Subjects -> BIOLOGY (Total: 3174 journals)
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BIOLOGY (1491 journals)            First | 1 2 3 4 5 6 7 8 | Last

Showing 201 - 400 of 1720 Journals sorted alphabetically
Biological Research     Open Access   (Followers: 1)
Biological Rhythm Research     Hybrid Journal   (Followers: 1)
Biological Theory     Hybrid Journal   (Followers: 3)
Biological Trace Element Research     Hybrid Journal  
Biologicals     Full-text available via subscription   (Followers: 7)
Biologics: Targets & Therapy     Open Access   (Followers: 1)
Biologie Aujourd'hui     Full-text available via subscription  
Biologie in Unserer Zeit (Biuz)     Hybrid Journal   (Followers: 36)
Biologija     Open Access  
Biology     Open Access   (Followers: 3)
Biology and Philosophy     Hybrid Journal   (Followers: 18)
Biology Bulletin     Hybrid Journal   (Followers: 1)
Biology Bulletin Reviews     Hybrid Journal  
Biology Direct     Open Access   (Followers: 9)
Biology Letters     Full-text available via subscription   (Followers: 44)
Biology Methods and Protocols     Open Access  
Biology of Sex Differences     Open Access   (Followers: 1)
Biology of the Cell     Full-text available via subscription   (Followers: 9)
Biology Open     Open Access  
Biology, Medicine, & Natural Product Chemistry     Open Access   (Followers: 2)
Bioma : Jurnal Ilmiah Biologi     Open Access  
Biomacromolecules     Hybrid Journal   (Followers: 23)
Biomarker Insights     Open Access   (Followers: 2)
Biomarkers     Hybrid Journal   (Followers: 4)
Biomass and Bioenergy     Partially Free   (Followers: 8)
Biomaterials     Hybrid Journal   (Followers: 55)
Biomaterials Advances     Full-text available via subscription   (Followers: 19)
Biomath     Open Access  
Biomatter     Open Access  
Biomechanics and Modeling in Mechanobiology     Hybrid Journal   (Followers: 8)
Biomedical Chromatography     Hybrid Journal   (Followers: 6)
Biomedical Engineering     Hybrid Journal   (Followers: 11)
Biomedical Engineering and Computational Biology     Open Access   (Followers: 11)
BioMedical Engineering OnLine     Open Access   (Followers: 4)
Biomedical Engineering: Applications, Basis and Communications     Hybrid Journal   (Followers: 4)
Biomedical Journal     Open Access   (Followers: 5)
Biomedical Science and Engineering     Open Access   (Followers: 5)
Biomedical Signal Processing and Control     Hybrid Journal   (Followers: 9)
BioMetals     Hybrid Journal   (Followers: 1)
Biometrical Letters     Open Access  
Biometrics     Hybrid Journal   (Followers: 51)
Biometrika     Hybrid Journal   (Followers: 21)
Biomimetic Intelligence and Robotics     Open Access  
Biomolecular NMR Assignments     Hybrid Journal   (Followers: 3)
Biomolecules     Open Access   (Followers: 1)
BioNanoScience     Partially Free   (Followers: 3)
Bionature     Open Access   (Followers: 1)
Biopreservation and Biobanking     Hybrid Journal   (Followers: 2)
Bioprocess and Biosystems Engineering     Hybrid Journal   (Followers: 9)
Bioresource Technology     Partially Free   (Followers: 9)
BioRisk     Open Access   (Followers: 2)
Biosaintifika : Journal of Biology & Biology Education     Open Access  
BioScience     Hybrid Journal   (Followers: 27)
Biosecurity and Bioterrorism: Biodefense Strategy, Practice, and Science     Hybrid Journal   (Followers: 3)
Biosemiotics     Hybrid Journal   (Followers: 1)
Biosensors     Open Access   (Followers: 3)
Biosensors and Bioelectronics     Hybrid Journal   (Followers: 27)
Biosensors and Bioelectronics : X     Open Access   (Followers: 2)
Bioseparation     Hybrid Journal   (Followers: 1)
Biosfer : Jurnal Biologi dan Pendidikan Biologi     Open Access  
Biosfer : Jurnal Tadris Biologi     Open Access  
BioSocieties     Hybrid Journal   (Followers: 3)
Biospecies     Open Access  
BIOspektrum     Hybrid Journal   (Followers: 5)
Biostatistics     Hybrid Journal   (Followers: 18)
Biosystematics and Ecology     Open Access   (Followers: 2)
Biosystems     Hybrid Journal   (Followers: 3)
Biosystems Diversity     Open Access  
Biota Amazônia     Open Access  
Biota Neotropica     Open Access  
Biotechnology Advances     Hybrid Journal   (Followers: 34)
Biotropia : The Southeast Asian Journal of Tropical Biology     Open Access  
Biotropica     Hybrid Journal   (Followers: 19)
Birth Defects Research     Hybrid Journal  
BJHM Open Research     Full-text available via subscription  
BMC Bioinformatics     Open Access   (Followers: 110)
BMC Biology     Open Access   (Followers: 50)
BMC Developmental Biology     Open Access   (Followers: 13)
BMC Evolutionary Biology     Open Access   (Followers: 58)
BMC Genomics     Open Access   (Followers: 69)
BMC Molecular and Cell Biology     Open Access   (Followers: 40)
BMC Proceedings     Full-text available via subscription   (Followers: 2)
BMC Research Notes     Open Access   (Followers: 3)
BMC Structural Biology     Open Access   (Followers: 8)
BMC Systems Biology     Open Access   (Followers: 16)
Boletín Científico : Centro de Museos. Museo de Historia Natural     Open Access  
Boletín del Centro de Investigaciones Biológicas     Open Access  
Boletín Micológico     Open Access  
Bone Reports     Open Access  
Bonorowo Wetlands     Open Access  
Borneo Journal of Resource Science and Technology     Open Access  
Bothalia : African Biodiversity & Conservation     Open Access  
Brain Science Advances     Open Access  
Brazilian Journal of Biological Sciences     Open Access  
Breastfeeding Medicine     Hybrid Journal   (Followers: 20)
Briefings in Bioinformatics     Hybrid Journal   (Followers: 43)
Briefings in Functional Genomics     Hybrid Journal   (Followers: 3)
British Poultry Abstracts     Hybrid Journal   (Followers: 3)
Brittonia     Hybrid Journal  
Bulletin de la Société Royale des Sciences de Liège     Open Access  
Bulletin of Experimental Biology and Medicine     Hybrid Journal  
Bulletin of Mathematical Biology     Hybrid Journal   (Followers: 9)
Bulletin of the Ecological Society of America     Open Access   (Followers: 4)
Bulletin of the Lebedev Physics Institute     Hybrid Journal  
Butlletí de la Institució Catalana d'Història Natural     Open Access  
CABI Agriculture and Bioscience     Open Access   (Followers: 1)
Caldasia     Open Access  
Cameroon Journal of Experimental Biology     Open Access  
Canadian Journal of Bioethics     Open Access  
Canadian Journal of Plant Pathology     Hybrid Journal   (Followers: 3)
Çanakkale Onsekiz Mart University Journal of Marine Sciences and Fisheries     Open Access  
Cancer Biology & Therapy     Open Access   (Followers: 11)
Cancer Cell International     Open Access   (Followers: 7)
Carbon Capture Science & Technology     Open Access  
Carbon Management     Hybrid Journal   (Followers: 5)
Carbon Resources Conversion     Open Access   (Followers: 2)
Caryologia : International Journal of Cytology, Cytosystematics and Cytogenetics     Partially Free  
Caucasiana     Open Access  
Cell     Full-text available via subscription   (Followers: 1140)
Cell Adhesion & Migration     Open Access   (Followers: 9)
Cell and Tissue Banking     Hybrid Journal   (Followers: 1)
Cell and Tissue Biology     Hybrid Journal   (Followers: 4)
Cell and Tissue Research     Hybrid Journal   (Followers: 5)
Cell Biochemistry and Function     Hybrid Journal   (Followers: 8)
Cell Biology and Development     Open Access   (Followers: 2)
Cell Biology and Toxicology     Hybrid Journal   (Followers: 10)
Cell Biology Education     Free   (Followers: 4)
Cell Biology International     Hybrid Journal   (Followers: 4)
Cell Biology International Reports     Hybrid Journal   (Followers: 2)
Cell Calcium     Hybrid Journal   (Followers: 2)
Cell Communication & Adhesion     Hybrid Journal   (Followers: 2)
Cell Cycle     Full-text available via subscription   (Followers: 5)
Cell Death and Differentiation     Hybrid Journal   (Followers: 7)
Cell Discovery     Open Access   (Followers: 2)
Cell Division     Open Access   (Followers: 1)
Cell Genomics     Full-text available via subscription   (Followers: 2)
Cell Metabolism     Full-text available via subscription   (Followers: 58)
Cell Proliferation     Open Access  
Cell Reports     Open Access   (Followers: 61)
Cell Reports Medicine     Open Access   (Followers: 3)
Cell Reports Methods     Open Access   (Followers: 1)
Cell Research     Hybrid Journal   (Followers: 11)
Cell Stress and Chaperones     Hybrid Journal   (Followers: 1)
Cell Surface     Open Access  
Cell Systems     Hybrid Journal   (Followers: 7)
Cells     Open Access   (Followers: 2)
Cells & Development     Hybrid Journal   (Followers: 3)
Cells Tissues Organs     Full-text available via subscription   (Followers: 1)
Cellular Immunology     Hybrid Journal   (Followers: 29)
Cellular Logistics     Full-text available via subscription  
Cellular Microbiology     Hybrid Journal   (Followers: 12)
Cellular Oncology     Hybrid Journal   (Followers: 3)
Cellular Reprogramming     Hybrid Journal  
Cellular Signalling     Hybrid Journal   (Followers: 10)
Ceylon Journal of Science     Open Access  
Channels     Open Access   (Followers: 1)
Check List : The Journal of Biodiversity Data     Open Access   (Followers: 2)
Chem     Hybrid Journal  
ChemBioEng Reviews     Full-text available via subscription   (Followers: 3)
Chemosensory Perception     Hybrid Journal  
Chirality     Hybrid Journal  
Chromosoma     Hybrid Journal  
Chromosome Research     Hybrid Journal   (Followers: 2)
Ciencia     Open Access  
Ciencia Amazónica (Iquitos)     Open Access  
Ciência ET Praxis     Open Access  
CienciaUAT     Open Access  
Cladistics     Hybrid Journal   (Followers: 7)
Climate Change Ecology     Open Access   (Followers: 14)
Clinical Dysmorphology     Hybrid Journal  
Clinical Phytoscience     Open Access  
Clinical Proteomics     Open Access   (Followers: 3)
Clinical Spectroscopy     Open Access  
Coevolution     Open Access  
Cogent Biology     Open Access  
Cognitive Neurodynamics     Hybrid Journal   (Followers: 2)
Cold Spring Harbor Perspectives in Biology     Full-text available via subscription   (Followers: 3)
Cold Spring Harbor Protocols     Full-text available via subscription   (Followers: 4)
Communication in Biomathematical Sciences     Open Access   (Followers: 2)
Communications Biology     Open Access  
Communications in Applied Sciences     Open Access  
Communications Materials     Open Access  
Communicative & Integrative Biology     Open Access  
Community Ecology     Full-text available via subscription   (Followers: 27)
Comparative Medicine     Full-text available via subscription   (Followers: 5)
Composite Interfaces     Hybrid Journal   (Followers: 6)
Comptes Rendus : Chimie     Open Access  
Comptes Rendus Biologies     Open Access   (Followers: 1)
Computational Biology Journal     Open Access   (Followers: 6)
Computational Mathematics and Mathematical Physics     Hybrid Journal   (Followers: 5)
Computer Methods in Biomechanics and Biomedical Engineering     Hybrid Journal   (Followers: 10)
Computer Methods in Biomechanics and Biomedical Engineering : Imaging & Visualization     Hybrid Journal  
Computers in Biology and Medicine     Hybrid Journal   (Followers: 11)
Connective Tissue Research     Hybrid Journal  
Contact (CTC)     Open Access  
Contributions to Plasma Physics     Hybrid Journal   (Followers: 3)
CRISPR Journal     Hybrid Journal  
Critical Reviews in Clinical Laboratory Sciences     Hybrid Journal   (Followers: 19)
Crustaceana     Hybrid Journal   (Followers: 6)
Cryobiology     Hybrid Journal   (Followers: 3)

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BioRisk
Journal Prestige (SJR): 2.568
Citation Impact (citeScore): 6
Number of Followers: 2  

  This is an Open Access Journal Open Access journal
ISSN (Print) 1313-2644 - ISSN (Online) 1313-2652
Published by Pensoft Homepage  [58 journals]
  • Studies on the Bulgarian members of the family Chenopodiaceae s.
           stricto: a review

    • Abstract: BioRisk 18: 17-34
      DOI : 10.3897/biorisk.18.78548
      Authors : Vanya Stoyanova Boneva, Nadezhda Traycheva Petkova : The Bulgarian members of Chenopodiaceae are mainly ruderal and weed species; another part are halophytes. Over the last two decades, phylogenetic molecular studies have led to a number of taxonomic changes in the above mentioned family. Changes have also occurred in one of the largest genera – Chenopodium. The aim of the present study is to review the research on Bulgarian members of the Chenopodiaceae family. The data available in the literature on the taxonomic composition, chorology, morphological features and karyological variability of the species from their Bulgarian populations has been studied. A review of the phytochemical studies of Chenopodiaceae plants from their Bulgarian populations has been made. The systematized data is presented in chronological order, which allows for tracing the current level of study on the family in Bulgaria and opportunities for new research. HTML XML PDF
      PubDate: Wed, 27 Apr 2022 11:25:04 +030
       
  • Relocation and formation of new local population of Viola pumila Chaix
           – an endangered species in Europe and identification of measures for
           improvement of its habitat

    • Abstract: BioRisk 18: 1-16
      DOI : 10.3897/biorisk.18.76114
      Authors : Maria Zh. Kaschieva, Nikolay P. Nedyalkov : The meadow violet (Viola pumila Chaix) is an endangered species which is regionally extinct in many European countries. This is a stenobiontic species with a very limited distribution in Bulgaria. Only a few populations have been detected, and they consist of several tens to several hundreds of specimens. The meadow violet has limited reproductive abilities and weak competitiveness. The species is exposed to various anthropogenic threats, as the most significant of them are related to ploughing, conversion of the mesophilic meadows into arable lands, changes in the water regime of the habitats, the expansion of highly competitive species from the group of tufted cereal grasses and infrastructure construction. To date, information concerning the relocation of rare and endangered plant species in Bulgaria is rather scarce. In the present study we provide a protocol on our activities during a successful establishment of a new locality as part of our effort to successfully relocate one particular population of the meadow violet. The observations made after the relocation of the species over a two-year period (2020 and 2021) provided data on the successful relocation, and the creation of a new locality for the species. We discuss the conservation measures needed for this rare and endangered species, and efforts to increase its population, as well as the measures needed for effective management of the habitats of V. pumila (mainly 6510 “Lowland hay meadows”). HTML XML PDF
      PubDate: Wed, 27 Apr 2022 11:24:36 +030
       
  • Development of accurate chemical thermodynamic database for geochemical
           storage of nuclear waste. Part III: Models for predicting solution
           properties and solid-liquid equilibrium in cesium binary and mixed systems
           

    • Abstract: BioRisk 17: 407-422
      DOI : 10.3897/biorisk.17.77523
      Authors : Tsvetan Tsenov, Stanislav Donchev, Christomir Christov : The models described in this study are of high importance in the development of thermodynamic database needed for nuclear waste geochemical storage as well as for technology for extracting cesium resources from saline waters. In this study we developed new not concentration restricted thermodynamic models for solution behavior and solid-liquid equilibrium in CsF-H2O CsOH-H2O and Cs2SO4-H2O systems at 25 °C. To parameterize models we used all available experimental osmotic coefficients data for whole concentration range of solutions and up to saturation point. The new models are developed on the basis of Pitzer ion interactions approach. The predictions of new developed here models are in excellent agreement with experimental osmotic coefficients data (ϕ) in binary solutions from low to extremely high concentration (up to 21.8 mol.kg-1 for CsOH-H2O and up to 35.6 mol.kg-1 for CsF-H2O). The previously developed by Christov by Christov and co-authors and by other authors Pitzer approach based thermodynamic models for five (5) cesium binary systems (CsCl-H2O CsBr- H2O CsI-H2O CsNO3-H2O and Cs2SeO4- H2O) are tested by comparison with experimental osmotic coefficients data and with recommendations on activity coefficients (γ±) in binary solutions. The models which give the best agreement with (ϕ)- and (γ±) -data from low to high concentration up to m(sat) are accepted as correct models which can be used for solubility calculations in binary and mixed systems and determination of thermodynamic properties of precipitating cesium solid phases. The thermodynamic solubility products (ln Kosp) and the Deliquescence Relative Humidity (DRH) of solid phases precipitating from saturated cesium binary solutions (CsF(cr) CsCl(cr) CsBr(cr) CsI(cr) CsOH(cr) CsNO3(cr) Cs2SO4(cr) and Cs2SeO4(cr)) have been determined on the basis of evaluated and accepted binary parameters and using experimental solubility data. The reported mixing parameters [θ(Cs M2+) and ψ(Cs M2+ X)] evaluated by solubility approach for 15 cesium mixed ternary systems (CsCl-MgCl2-H2O CsBr-MgBr2-H2O CsCl-NiCl2-H2O CsBr-NiBr2-H2O CsCl-MnCl2-H2O CsCl-CoCl2-H2O CsCl-CuCl2-H2O CsCl-CsBr-H2O CsCl-RbCl-H2O Cs2SO4-CoSO4-H2O Cs2SeO4-CoSeO4-H2O Cs2SO4-NiSO4-H2O Cs2SeO4-NiSeO4-H2O Cs2SO4-ZnSO4-H2O and Cs2SeO4-ZnSeO4-H2O) are tabulated. HTML XML PDF
      PubDate: Thu, 21 Apr 2022 19:00:36 +030
       
  • Development of accurate chemical thermodynamic database for geochemical
           storage of nuclear waste. Part II: Models for predicting solution
           properties and solid-liquid equilibrium in binary nitrate systems

    • Abstract: BioRisk 17: 389-406
      DOI : 10.3897/biorisk.17.77487
      Authors : Stanislav Donchev, Tsvetan Tsenov, Christomir Christov : The main purpose of this study is to develop new thermodynamic models for solution behavior and solid-liquid equilibrium in 10 nitrate binary systems of the type 2–1 (Mg(NO3)2-H2O, Ca(NO3)2-H2O, Ba(NO3)2-H2O, Sr(NO3)2-H2O, and UO2(NO3)2-H2O), 3–1 (Cr(NO3)3-H2O, Al(NO3)3-H2O, La(NO3)3-H2O, Lu(NO3)3-H2O), and 4–1 (Th(NO3)4-H2O) from low to very high concentration at 25 °C. To construct models, we used different versions of standard molality-based Pitzer approach. To parameterize models, we used all available raw experimental osmotic coefficients data (φ) for whole concentration range of solutions, and up to supersaturation zone. The predictions of developed models are in excellent agreement with φ-data, and with recommendations on activity coefficients (γ±) in binary solutions from low to very high concentration. The Deliquescence Relative Humidity (DRH), and thermodynamic solubility product (as ln K°sp) of 12 nitrate solid phases, precipitating from saturated binary solutions have been calculated. The concentration-independent models for nitrate systems described in this study are of high importance for development of strategies and programs for nuclear waste geochemical storage. HTML XML PDF
      PubDate: Thu, 21 Apr 2022 19:00:35 +030
       
  • Pre-monitoring geochemical research of the river sediments in the area
           of Ada Tepe gold mining site (Eastern Rhodopes)

    • Abstract: BioRisk 17: 379-387
      DOI : 10.3897/biorisk.17.77466
      Authors : Dimitar Zhelev, Rumen Penin : The article depicts the geochemical properties of the landscapes in the Ada Tepe gold mine area before its launching. The research is conducted by examining the heavy metals (Cu, Pb, Zn, Co, Cr, Mn and Ni) content in samples of river sediments in the local landscapes. The research aims to analyse the concentration of heavy metals before the launch of gold mining. The study implements the coefficient of Clarke concentration. The deviation from the background concentrations is a ratio between the element concentration in the collected environmental samples and the Clarke value of the element. The coefficient has a scale from 0 to a particular positive value, corresponding to the level of enrichment of the sample in comparison to the background Clarke value. The values corresponding to the Clarke concentration are equal to 1, the lower values are between 0 and 1 (dispersion) and any value higher than 1 is a case of concentration (enrichment). The obtained results display the researched territory as a natural background area. The content of heavy metals in the river sediments of the researched area (mg/kg, median value) by chemical elements is Cu (15), Zn (72), Pb (17), Mn (461), Ni (35), Co (8) and Cr (60). That is the reason it could be defined as not impacted by human activities and it is not influenced by natural geochemical anomalies. Heavy metals do not pollute the researched landscapes before mining. This outcome is obtained by the geochemical content of the investigated heavy metals in the river sediments. HTML XML PDF
      PubDate: Thu, 21 Apr 2022 19:00:34 +030
       
  • Forests of Breznik municipality

    • Abstract: BioRisk 17: 367-377
      DOI : 10.3897/biorisk.17.77388
      Authors : Borislav Grigorov, Nikolay Velev, Assen Assenov, Momchil Nazarov, Beloslava Genova, Kiril Vassilev : The current study aims to uncover the forest habitat diversity of Breznik municipality, following the EUNIS Classification. Initial data was collected from the Ministry of Environment and Water and the Forestry Management Plans. Forest habitat polygons were spatially processed with the use of the ArcGIS 10.8.1 software package. Field studies were performed to add more detailed information to the analysis. The phytocoenoses of the forest habitats are dominated by Quercus dalechampii, Q. frainetto, Fagus sylvatica, Carpinus betulus. Some artificial plantations with Pinus nigra and P. sylvestris were also present, as well as with non-native species, such as Robinia pseudacacia and Quercus rubra. The results of this study could be used for more in-depth research of the Breznik municipality vegetation. HTML XML PDF
      PubDate: Thu, 21 Apr 2022 19:00:33 +030
       
  • Comparative determination of antimicrobial activity of the Balkan
           endemic species Stachys thracica Davidov during the process of ex situ
           conservation

    • Abstract: BioRisk 17: 357-365
      DOI : 10.3897/biorisk.17.77484
      Authors : Desislava Mantovska, Detelina Petrova, Lybomira Yocheva, Zhenya Yordanova : Stachys thracica Davidov – Thracian woundwort is a Balkan endemic plant included in The Red Data Book of Bulgaria with conservational status “rare”. The plants from genus Stachys have a long history of use to treat various diseases, inflammatory conditions, coughs, ulcers, genital tumors, and infected wounds. Due to its limited distribution the information on the biological activity and chemical composition of S. thracica is rather scarce. The aim of the present research is the comparative determination of the antimicrobial activity of methanolic extracts obtained from in situ wild, in vitro cultivated and ex vitro adapted S. thracica plants. The in vitro shoot culture of the Thracian woundwort was maintained in hormone-free MS medium under controlled environmental conditions. The methanolic extracts from in situ, in vitro cultivated and ex vitro adapted S. thracica plants were active mainly against Gram-negative bacteria. All three extracts showed equal activity against Acinetobacter calcoaceticus. The establishment of in vitro shoot culture and its subsequent adaptation in ex vitro conditions was an appropriate alternative approach for the ex situ conservation of S. thracica as well as for the study of its biological activity. HTML XML PDF
      PubDate: Thu, 21 Apr 2022 19:00:32 +030
       
  • Influence of some environmental factors on the distribution of
           zooplankton complexes in Mandra Reservoir, in Southeastern Bulgaria

    • Abstract: BioRisk 17: 343-355
      DOI : 10.3897/biorisk.17.77368
      Authors : Eleonora Fikovska, Dimitar Kozuharov, Marieta Stanachkova : The aim of the present study was to trace the influence of some environmental factors (w.temperature, wind, transparency, depth) on the distribution of zooplankton communities in the system Reservoir Mandra and the ecotone zones formed at the confluence of rivers Fakiyska, Sredetska, Izvorska and Rusokastrenska. Four samplings were performed at seven sites between February 2020 and January 2021. After determining the species composition and abundance, the results were subjected to structural analysis and Canonical Correspondence Analysis (CCA). A total of 67 taxa were identified, constituting about 48% of the Rotifera group, 27% of Cladocera and 19% of the Copepoda and only 6% from Protozoa. The Shannon-Weaver index for individual species diversity was between 2.37 and 0.62. The positive and negative correlation of zooplankton distribution in CCA shows that the relative abundance of any species depends on specific environmental variables. Analysis showed that temperature and wind had the strongest impact on the distribution of zooplankton. HTML XML PDF
      PubDate: Thu, 21 Apr 2022 19:00:31 +030
       
  • Pteromalid fauna (Hymenoptera, Pteromalidae) in oilseed rape (Brassica
           napus L.) fields in Bulgaria – species composition and perspectives for
           biological control

    • Abstract: BioRisk 17: 329-342
      DOI : 10.3897/biorisk.17.77454
      Authors : Ivaylo Todorov, Toshko Ljubomirov, Vlada Peneva : Parasitoid wasps belonging to the family Pteromalidae are widespread and abundant members of the insect communities in the temperate regions of the world. As many other chalcids do, pteromalids serve as natural enemies of the pests in various crops and play an important role in the biological control of these harmful insects. Here we present the results of a field study in Bulgaria which was focused on the diversity of family Pteromalidae in ten oilseed rape fields. All samples were collected by sweep netting on the border line or inside the crop field. A total of 93 pteromalid specimens belonging to 26 taxa were gathered. The most abundant genus was Mesopolobus – 67% of the sampled pteromalids. The most numerous species in the samples was Mesopolobus morys – a well-known key parasitoid of the cabbage seed weevil, Ceutorhynchus obstrictus, in Europe. One species – Halticoptera patellana, is recorded for the first time in Bulgarian fauna. Clearfield oilseed rape fields had relatively higher parasitoid abundance and richness than the fields treated by conventional technology. In the present work we discuss the overall species composition of Pteromalidae obtained from the studied areas and present our point of view on the perspectives for biological control of oilseed rape pests. HTML XML PDF
      PubDate: Thu, 21 Apr 2022 19:00:30 +030
       
  • Monitoring bumblebee pollinator visits to the medicinal plant Gentiana
           asclepiadea L. (Gentianacese) – a comparison between the periods
           1990–1994 and 2017–2020

    • Abstract: BioRisk 17: 317-327
      DOI : 10.3897/biorisk.17.76577
      Authors : Ekaterina Kozuharova, Vasil Simeonov : Ever increasing data continue to indicate the decline of bumblebee populations. The key factors causing declines in their abundance and diversity are: 1) habitat destruction, 2) loss of floral resources, 3) emerging diseases, 4) increased use of pesticides (particularly neonicotinoids). The aim of this study is to monitor bumblebee visits to Gentiana asclepiadea L, recording pollinator species, and taking measurements of seed set. This plant species is chosen for two reasons: 1) similar data is available from our previous research in the 1990’s and 2) this montane plant species is supposed to be less exposed to hazards from pesticides and habitat destruction. Three study sites were chosen in Mt. Vitosha (SW Bulgaria) where natural populations of G. asclepiadea occur in 1990. The observations of bumblebee activity in the flowers of G. asclepiadea were conducted during the flowering seasons (August and September) of 2017 – 2020 at the same study sites and compared to the data obtained in the previous period (1990–1994). The free pollination fruit set was tested by monitoring of 100 G. asclepiadea flowers each year for development of fruit capsules. The seed set was tested by counting the matured seeds and non-fertilised ovules of 10 fruit capsules each year. A slight decline in bumblebee activity was recorded in 2017 – 2020 in comparison to 1990–1994. This is reflected in the fruit set and the seed set. Our data demonstrates that even in a mountain habitat, where there are fewer direct hazards to bumblebees, that pollination effectiveness has been suppressed over time. This corresponds to a research study which provides evidence that insect biomass fell by 76% in German nature reserves between 1989 and 2016. HTML XML PDF
      PubDate: Thu, 21 Apr 2022 19:00:29 +030
       
  • Plant products with acetylcholinesterase inhibitory activity for
           insect control

    • Abstract: BioRisk 17: 309-315
      DOI : 10.3897/biorisk.17.77052
      Authors : Borislav Georgiev, Milena Nikolova, Ina Aneva, Anatoli Dzhurmanski, Boriana Sidjimova, Strahil Berkov : Acetylcholinesterase (AChE) inhibitors are widely used in Alzheimer’s treatment, but they are also crucial for their action on organophosphorus insecticides. The latter exert their toxicity by inhibiting the AChE enzyme in insects, leading to their death. Amaryllidaceae alkaloids have been proven to be potent AChE inhibitors. In the present study methanolic extracts and essential oils being obtained from species of Asteraceae, Lamiaceae, Brassicaceae and Amaryllidaceae were evaluated in vitro for AChE inhibitory activity. Ellman’s colourimetric method, with modifications, was used for AChE activity evaluation. According to the activity level, the tested plant products were divided into three categories. First: plant products with strong activity comparable to that of galanthamine; second: plant products with medium activity, with IC50 value about 1 mg/ml and the last group with low activity, with IC50 value greater than 1 mg/ml. Essential oils of Origanum vulgare subsp. hirtum Ietswaart., Satureja pilosa Vel., Monarda fistulosa L., Thymus longedentatus (Degen & Urum.) Ronniger and the methanolic extract of Leucojum aestivum L. showed the most potent activity and were referred to as the first group. Carvacrol was identified as the main component of the most active essential oils. In L. aestivum extract, galanthamine was found as the main alkaloid. The obtained results indicate that essential oils and alkaloid-rich plant extracts possess the strongest AChE inhibitory activity. This gives us a reason to recommend these plant products to be tested for insecticidal activity in the future. HTML XML PDF
      PubDate: Thu, 21 Apr 2022 19:00:28 +030
       
  • Pollinators of Lavandula angustifolia Mill., an important factor for
           optimal production of lavender essential oil

    • Abstract: BioRisk 17: 297-307
      DOI : 10.3897/biorisk.17.77364
      Authors : Hristo Valchev, Zdravko Kolev, Bilyana Stoykova, Ekaterina Kozuharova : Lavender essential oil is widely used in pharmacy, perfumery and the food industry. It is one of the key essential oils in aromatherapy due to its valuable pharmacological properties. The producers of lavender essential oil are well aware that the greatest quantity of oil is obtained near the end of the inflorescence anthesis and that oil quantity is correlated with the pollination as unpollinated flowers drop down. In addition, it has been demonstrated that oil quality is also highest at the end of the flowering period, related to the gradual increase of monoterpenes (particularly the valuable linalool) and the decrease of sesquiterpenes during flower ontogenesis. The aim of this preliminary study was to measure the occurrence of spontaneous self-pollination in Lavandula angustifolia Mill. and to identify external pollinators. The field experiments were performed in a lavender plantation near Gorna Lipnitza Village, north Bulgaria and in the ex-situ lavender collection in the experimental plot of the Botanical Garden of Sofia University. It was revealed that spontaneous self-pollination did not occur in flowers from which external pollinators had been excluded. Exposed flowers were pollinated by polylectic insects, such as honeybees, several species of bumblebees and butterflies. Wild pollinators (particularly bumblebees) dominated over honeybees at both study sites. Our observations showed that all pollinators actively collected nectar. The pollen baskets of most bees were full, indicating the active consolidation of pollen adhering to the pollinators’ bodies. Although lavender growers tend to place beehives in the fields for optimal essential oil production, it is also crucial to conserve wild pollinators. HTML XML PDF
      PubDate: Thu, 21 Apr 2022 19:00:27 +030
       
  • Evaluation of viral infection levels in intensive and organic
           poultry farming

    • Abstract: BioRisk 17: 287-296
      DOI : 10.3897/biorisk.17.77398
      Authors : Plamen M. Kirov, Radostina I. Alexandrova : Whereas early organic farming was mainly focused on plant production, in the last decade, the number of organically-managed poultry farms within the European Union has increased significantly. Similar to organic crop production, organic animal farming is based on the same principles: welfare-friendly, sustainable production and resource utilisation without or with very little addition of synthetic substances, such as antibiotics and antiparasitic treatments. These practices, as well as the access to wild animals, make the free-range poultry production systems predisposed to different viral diseases and, thus, associated with potentially higher public health risks or reduction in production quality. On the other hand, intensive farming amplifies the impact of viral diseases due to high density, low genetic diversity and elevated immunodeficiency. The aim of this analytical study is to compare free-range with intensive poultry systems and the occurrence of different viral diseases in these types of farms in the EU over the past decade. The research is based on official data from the statistical office of the European Union, as well as official data from the Member countries. The results were similar in each country and demonstrate that free-range production has a higher incidence of viral diseases with high zoonotical potential. This makes year-round surveillance absolutely necessary, as well as the need for implementation of additional criteria and requirements towards free-range systems. HTML XML PDF
      PubDate: Thu, 21 Apr 2022 19:00:26 +030
       
  • Organic vs conventional farming of oil-bearing rose: Effect on
           essential oil and antioxidant activity

    • Abstract: BioRisk 17: 271-285
      DOI : 10.3897/biorisk.17.77488
      Authors : Mima Todorova, Ana Dobreva, Nadezhda Petkova, Neli Grozeva, Mariya Gerdzhikova, Petya Veleva : The aim of this study was to establish whether the type of the agricultural system has any influence on the essential oil production and antioxidant activity of industrial cultivated Rosa damascena Mill. in the Rose valley, Bulgaria. Six private farms from Kazanlak (Rose) Valley, Southern Bulgaria were included in the study conducted in the period 2019–2020. The first three selected farms are designated within the conventional farming and the other three are certificated as organic farms. GC/FID and GC/MS analyses were performed; the contents of total polyphenols and flavonoids in the methanol extracts from rose petals were determined. Additionally, the antioxidant activity of rose extracts was evaluated by four reliable methods: 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2´-azino-bis-3-ethylbenzthiazoline-6-sulphonic acid (ABTS), ferric reducing antioxidant power (FRAP), and cupric reducing antioxidant capacity (CUPRAC) assays. The impact of the agricultural system on the essential oil composition and antioxidant activity was evaluated by ANOVA statistical analysis. The results obtained showed that organic farming produced essential oil with a higher linalool and geraniol content and lower β-citronellol + nerol concentrations than conventional farming. It was found that organic farming production demonstrated a better antioxidant activity evaluated by the three DPPH, ABTS, and CUPRAC methods according to the averaged data for two years, 806.82, 797.66 and 1534.40 mM TE/g dw versus 510.34, 521.94 and 917.48 mM TE/g dw for CF, respectively, with high statistical significance for the DPPH and ABTS analyses. Consequentially, the rose extracts from the organic farming accumulated more phenolic compounds that corresponded to the higher antioxidant potential of the organic roses. HTML XML PDF
      PubDate: Thu, 21 Apr 2022 19:00:25 +030
       
  • Sexually-manifested variations in pigmentation of Boeckella poppei
           (Copepoda, Calanoida) from Livingston Island (Maritime Antarctica)

    • Abstract: BioRisk 17: 263-269
      DOI : 10.3897/biorisk.17.75988
      Authors : Ivan Pandourski, Vesela Evtimova, Lyubomir Kenderov : Antarctic environments are exposed to high levels of ultraviolet radiation (UVR) that are often detrimental to their biota. Recent studies suggest that the genus Boeckella (Copepoda, Calanoida) has a high level of plasticity in terms of its reaction to UVR, which enables its wide distribution in various water bodies in Antarctica. Boeckella poppei is common in freshwater habitats of all three main biogeographic regions in Antarctica: sub-Antarctic islands, maritime and continental. We present for the first time a specific photoprotective response in populations of B. poppei from Livingston Island, Maritime Antarctica. In non-ovigerous females and in males, we observed uniform distribution of carotenoids in the body, while these pigments were almost entirely concentrated in the ovisacs of mature females. We consider this as a means of progeny protection from the teratogenic influence of the high level of UVR in Antarctic environments. Unequivocally, such adaptation would facilitate the expansion of B. poppei on the continent through colonisation and survival in shallow freshwater habitats. Given that the Antarctic environment is dynamically changing over the past decades and the accelerated retreat of permanent ice cover is a premise for the formation of shallow ponds, B. poppei could be a suitable indicator for reflecting the ongoing global environmental changes in Antarctica. HTML XML PDF
      PubDate: Thu, 21 Apr 2022 19:00:24 +030
       
  • Seasonal variations of the microflora of wedge clam Donax trunculus
           (Linnaeus, 1758) from the region of Arkutino (Bulgarian Black Sea
           aquatory)

    • Abstract: BioRisk 17: 253-262
      DOI : 10.3897/biorisk.17.77097
      Authors : Sevginar Ibryamova, Borislava Pavlova, Elitca Stanachkova, Seniha Salim, Aysel Lyatif, Dimitar Dimitrov, Darina Bachvarova, Nesho Chipev, Nikolay Natchev, Tsveteslava Ignatova-Ivanova : The main goal of the present study was to investigate the impact of the state of the environment on the microbiota of the wedge clam Donax trunculus (Linnaeus, 1758) from the region of Arkutino (Bulgarian Black Sea aquatory). The species Enterococcus hirae was isolated during the summer (from May to August). The species P. mendocina prefers the warmer months and the species P. alcaligenes the colder ones. The temperature followed a course of decrease during the period September 2020 to January 2021, followed by a slow increase from February 2021. Comparing May 2020 with May 2021, it became evident that in 2021 the temperature was 1.5 °C lower. We can say that the number of the species P. alcaligenes was twice as high in May 2021. It is likely that this species preferred lower optimum temperatures and constant other parameters. For the species Enterococcus hirae such dependence was not observed - the number remained constant in May, but with increasing temperature the number of microorganisms decreased during the summer months. The species seemed to preferably develop at pH 7.78. The species A. gyllenbergii preferably grows at temperatures between 20.3–25.7 °C and the optimal temperature was 25.7 °C. For C. farmeri the optimum conditions were temperature 26.2 °C and pH 7.3. The species E. vulneris was probably related not only to the increase in water temperature, but also to the anthropogenic factor, as it was found only in July. HTML XML PDF
      PubDate: Thu, 21 Apr 2022 19:00:23 +030
       
  • Seasonal changes in the pro/antioxidant status of mussels Mytilus
           galloprovincialis (Lamarck, 1819) from Bulgarian Black Sea coastal
           habitats

    • Abstract: BioRisk 17: 241-251
      DOI : 10.3897/biorisk.17.77279
      Authors : Elina Tsvetanova, Almira Georgieva, Nesho Chipev, Albena Alexandrova : The pro/antioxidant status of marine macrozoobentic organisms is being increasingly applied in environmental monitoring and conservation programs. The oxidative stress level in marine bivalves can provide valuable information not only on the health of the organisms and their populations, but also on the current state of habitats and ecosystems. The aim of the present study was to make the first comprehensive investigation of the seasonal changes in the antioxidant activity in different organs (gills, digestive gland and foot) of M. galloprovincialis from representative Bulgarian Black Sea coastal habitats. The lipid peroxidation and glutathione levels, as well as activities of the antioxidant enzymes catalase, superoxide dismutase, glutathion peroxidase, glutathion reductase, glucose-6-phosphate dehydrogenase and glutathione-S-transferase of the organs were measured spectrophotometrically. Our hypothesis was that enhanced environmental pressure during the summer season, induced by multiple factors (biogenic, abiogenic and anthropogenic) led to weakening of the antioxidant protection in mussels at the beginning of autumn. The reaction of the mussel organism to the multiple stress factors was specific for the target organ and the type of the biomarker. Significant differences were present in the activity of the antioxidant system in mussels from the northern and southern coastal locations. The seasonal changes in the pro/antioxidant status of mussels were primarily due to specific seasonal changes in factors concerning the marine environment at the concrete locality. Further research is obviously needed to confirm the present results and provide a more complete data of seasonal and spatial changes in the antioxidant defense system of mussels from the Bulgarian Black Sea coastal area and their implementation in biomonitoring programs. HTML XML PDF
      PubDate: Thu, 21 Apr 2022 19:00:22 +030
       
  • Influence of proline and methyl jasmonate priming on in vitro seed
           germination and seedling development of Chelidonium majus L

    • Abstract: BioRisk 17: 227-240
      DOI : 10.3897/biorisk.17.77465
      Authors : Iva Doycheva : Drought, salinization and heavy metal pollution of soils are main stress factors with an increasing impact on the deterioration of soil quality, yield and crop quality. Seed priming shows good results in improving seed germination, seedling growth and plant development. Proline (Pro) and metyl jasmonate (MeJA) show stimulating activity and help plants overcome stress. The study investigated the effect of Pro, MeJA and hydropriming on seeds sown on water agar supplemented with different concentrations of heavy metals (Cd, Pb, Zn) (HM), NaCl or Polyethylene glycol 6000 (PEG 6000). Chelidonium majus is a medicinal species which is grown as a crop in some parts of Europe. It is an ingredient in some remedies and is becoming an increasingly popular object of research regarding its biological activities. The low concentrations of all heavy metals applied increased the germination of all variants of seeds – control, hydroprimed and those which were Pro and MeJA primed. Seed priming with Pro and MeJA promoted high germination percentage of seeds germinated on water agar with NaCl. PEG 6000 at its higher concentration (5%) slightly increased the seed germination of all variants. The growth of roots and hypocotyls was inhibited by HM and NaCl. However, PEG 6000 slightly influenced their growth. HTML XML PDF
      PubDate: Thu, 21 Apr 2022 19:00:21 +030
       
  • Light and auxin treatments affect morphogenesis and polyphenolics
           productivity in Artemisia alba Turra cell aggregates in vitro

    • Abstract: BioRisk 17: 213-225
      DOI : 10.3897/biorisk.17.77452
      Authors : Dobrina Pecheva, Kalina Danova : Artemisia alba Turra is an essential oil-bearing shrub, with a Euro-Mediterranean distribution widespread in the south-eastern parts of Europe. Phytochemical investigations have evidenced the presence of volatile mono- and sesquiterpene derivatives, as well as non-volatile sesquiterpenoids, flavonoids and phenolic acids contributing to the anti-inflammatory, antimicrobial, antioxidant and pro-apoptotic activity of different preparations, obtained from the plant. The current research aims at elucidation of the potential for biotechnological polyphenolic compounds productivity of non-differentiated cell lines of the plant. For this purpose, non-differentiated cell aggregates were initiated from either leaf or root explants of the sterile grown plant. They were cultivated either in the dark or at 16/8 h photoperiod in liquid media, supplemented with N6-benzyladenine (BA) as auxin. The cytokinin effects of indole-3-butyric acid (IBA) and 1-naphthalene acetic acid (NAA) were compared. It was established that NAA supplementation was superior to IBA and light treatment – to dark growth conditions in terms of polyphenolics productivity. In addition, NAA supplementation led to better expressed compaction and larger size of the cell aggregates as compared with IBA. The results of the present experiment indicate that secondary metabolites productivity in vitro is a dynamic process closely related to the plant’s growth and development and is in close relation to the interactions of the plant with its environmental conditions. HTML XML PDF
      PubDate: Thu, 21 Apr 2022 19:00:20 +030
       
  • Screening of Amorpha fruticosa and Ailanthus altissima extracts for
           genotoxicity/antigenotoxicity, mutagenicity/antimutagenicity and
           carcinogenicity/anticarcinogenicity

    • Abstract: BioRisk 17: 201-212
      DOI : 10.3897/biorisk.17.77327
      Authors : Teodora Todorova, Krassimir Boyadzhiev, Aleksandar Shkondrov, Petya Parvanova, Maria Dimitrova, Iliana Ionkova, Ilina Krasteva, Ekaterina Kozuharova, Stephka Chankova : The aim of the present study was to evaluate the potential genotoxic/antigenotoxic, mutagenic/antimutagenic, and carcinogenic/anticarcinogenic effect of Amorpha fruticosa (AF) fruit, Ailanthus altissima bark hexane (AAEH) and methanol (AAEM) extracts on a model system Saccharomyces cerevisiae. Plants were identified and extracted by Ekaterina Kozuharova. Three concentrations of each extract were tested – 10, 100 and 1000 µg/ml. In vitro pro-oxidant/antioxidant activities were evaluated by DPPH and DNA topology assay. The potential genotoxic/antigenotoxic, mutagenic/antimutagenic and carcinogenic/anticarcinogenic effects were revealed in vivo by: Zimmermman’s test on Saccharomyces cerevisiae diploid strain D7ts1, and Ty1 retrotransposition test on S. cerevisiae haploid strain 551. Zeocin was used as a positive control. Based on the in vitro antioxidant activity the extracts could be arranged as follows: AF>AAEM>AAEH. AAEH possessed moderate oxidative potential. No genotoxic and mutagenic capacity was obtained in vivo for extracts tested. The levels of total aberrants, convertants and revertants were comparable with the control ones. No Ty1 retrotransposition was induced by extracts treatment. Further, the extracts possessed well-expressed antigenotoxic, antimutagenic and anticarcinogenic activity. Significant reduction of the total aberrants, reverse point mutations and Ty1 retrotransposition was obtained. Only the AF extract was found to reduce the levels of zeocin-induced mitotic gene conversion. The three extracts did not possess any genotoxic, mutagenic and carcinogenic effect on Saccharomyces cerevisiae. Based on their protective activity, they can be arranged as follows: AF>AAEM>AAEH which corresponds well with their phytochemical composition. Further experiments could provide more detailed information concerning the mode of action of extracts, as well as their main constituents. HTML XML PDF
      PubDate: Thu, 21 Apr 2022 19:00:19 +030
       
  • Polar and non-polar fraction from Origanum vulgare spp. hirtum
           methanolic extract – differences in their bioactivity on Chlamydomonas
           reinhardtii test system

    • Abstract: BioRisk 17: 191-200
      DOI : 10.3897/biorisk.17.78169
      Authors : Maria Dimitrova Todorova, Petya Nikolaeva Parvanova, Teodora Ivanova Todorova, Milena Tihomirova Nikolova, Strahil Hristov Berkov, Stephka Georgieva Chankova : Aim: To compare the bioactivity of both polar and non-polar fraction of Origanum vulgare spp. hirtum methanolic extract on Chlamydomonas reinhardtii. Material and methods: The polar and non-polar fractions were derived from aerial parts of Origanum vulgare ssp. hirtum, collected during the flowering stage from the ex-situ collection of IBER-BAS. GC/MS analysis of both fractions was done following the standard protocol. The measured mass spectra were deconvoluted by the Automated Mass Spectral Deconvolution and Identification System (AMDIS), before comparison with the databases. Chlamydomonas reinhardtii 137C+ (WT) was used as a test system. Spot-test, cell survival fraction (SF), test of “visible mutations” and CFGE (for measurement of induced DNA double-strand breaks (DSBs)) were applied. Results: The polar fraction did not possess genotoxic, mutagenic as well as DNA-damaging effect. The situation with the non-polar fraction was quite different. Even at the lowest concentration of 250 ppm, cell survival was decreased by 60% (SF = 0.41 ± 0.08). Treatment with concentrations equal to/or greater than 500 ppm resulted in around 100% lethality. A mild mutagenic effect was obtained for the concentration of 250 ppm non-polar fraction (IM = 4.83 ± 0.004). Well-expressed and concentration-dependent induction of DSBs for even the strong DNA fragmentation was observed after the treatment with the non-polar fraction. Conclusions: The different bioactivity of the two fractions correlated well with their different chemical composition. The polar fraction, rich in sugars, organic acids and flavonoid glycosides, did not possess genotoxic and mutagenic potential. The strong genotoxic potential of the non-polar fraction might be related to carvacrol content (37.08%), which is not present in the composition of the polar fraction. To the best of our knowledge, this study provides the first information that the carvacrol-rich non-polar fraction of Origanum vulgare spp. hirtum methanolic extract possesses genotoxic, mutagenic and DNA damaging effect on some low eukaryotes, such as C. reinhardtii. Further experiments with carvacrol should be done in order to clarify the exact mechanism of action. HTML XML PDF
      PubDate: Thu, 21 Apr 2022 19:00:18 +030
       
  • On the mode of action of Origanum vulgare spp. hirtum methanolic
           extract and essential oil on Chlamydomonas reinhardtii

    • Abstract: BioRisk 17: 179-190
      DOI : 10.3897/biorisk.17.77313
      Authors : Maria D. Todorova, Petya N. Parvanova, Teodora I. Todorova, Georgi D. Dronchev, Milena T. Nikolova, Strahil H. Berkov, Stephka G. Chankova : Aim: To reveal whether methanolic extract and essential oil from Origanum vulgare subsp. hirtum in doses causing even low levels of mortality in aphids, would have harmful effects on plants-genotoxic, mutagenic and/or DNA damaging. Materials and methods: Aerial parts of Origanum vulgare ssp. hirtum from the ex-situ collection of IBER, BAS during flowering were collected. Extraction and isolation procedures, as well as GC/MS analysis of essential oil and methanolic extract were performed by standard protocols. The components were identified by comparing their relative retention times to the retention times of authentic standards, and with mass spectra with the NIST. Test system: Chlamydomonas reinhardtii strain 137 C+ (WT). Endpoints: “clonal” assay, the test of “visible mutations”, constant field gel electrophoresis. Statistics: GraphPad Prism version 6.04 (San Diego, USA) and One-way Analysis of Variance ANOVA with multiple comparisons using the Tukey method. Results: A good correlation was observed between chemical composition of essential oil and methanolic extract, and their mode of action. Our genotoxic and double strand breaks results demonstrated mild genotoxic and statistically non-significant DNA damaging potential of methanolic extract and concentration-dependent well - expressed genotoxic and DNA damaging potential of essential oil. A good relationship between increased double strand breaks levels and decreased survival might be related to one of the main constituents of essential oil, suspected to be carvacrol. No mutagenic effect for ME and EO was found. Conclusion: Well-expressed toxic/genotoxic capacity of essential oil, as well as its capacity to damage DNA inducing double strand breaks, but the absence of mutagenic potential, could be considered as a good reason to recommend Origanum vulgare subsp. hirtum essential oil as a promising candidate for purposes of “green” technologies. HTML XML PDF
      PubDate: Thu, 21 Apr 2022 19:00:17 +030
       
  • State of the antioxidant defense system in wedge clams from Bulgarian
           Black Sea as a measure of resistance to environmental impacts

    • Abstract: BioRisk 17: 169-178
      DOI : 10.3897/biorisk.17.77384
      Authors : Almira Georgieva, Elina Tsvetanova, Nesho Chipev, Albena Alexandrova : Pollution and climate change can induce oxidative stress (OS) in aquatic organisms. Reduced activity or incoordination between antioxidant enzymes in marine bivalves may cause cellular impairment with effects on higher levels of ecological organization. The present study aims to assess the condition factor and the activity of antioxidant enzymes catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GPx), glutathione-S-transferase (GST), and glutathione concentration (GSH) in soft tissues of Donax trunculus (Linnaeus, 1758) as indicators of the state of marine ecosystems along the Bulgarian Black Sea coast. The wedge clams were sampled manually from different localities in June and in September. The activity of antioxidant enzymes and GSH concentrations varied both seasonally and among localities. Higher values of GSH, SOD and GPx were registered in wedge clams collected in autumn compared to those collected in summer. In wedge clams higher activity of the major phase II detoxification enzyme GST was observed in summer at localities with intensive tourism, suggesting an activation of the cell detoxification processes, presumably in response to increased environmental pressure. In conclusion, the observed presence of elevated enzyme activities suggested activation of the antioxidant protection system of the wedge clams in response to environmental pressure, indicating their ability to cope with induced OS and adapt to local conditions, and thus maintain ecosystem health. HTML XML PDF
      PubDate: Thu, 21 Apr 2022 19:00:16 +030
       
  • Application of residual sludges from wastewater treatment technologies for
           construction of biofertiliser

    • Abstract: BioRisk 17: 157-168
      DOI : 10.3897/biorisk.17.77463
      Authors : Mihaela Belouhova, Dobromira Yaneva, Yana Topalova : To stimulate plant development in phytoremediation or in the cultivation of non-food crops in potentially contaminated soils, a biotechnologically created product could be applied. The aim of this study was to explore the possibility of creation of biofertiliser, based on activated sludge combined with bacterial strain with detoxifying and plant growth promoting properties. The presented study is focused on the effect of phenol in the following concentrations: 5 mg/l, 100 mg/l, 250 mg/l, 500 mg/l and 1000 mg/l on the metabolic activity of Brevibacillus laterosporus BT271. The gradual increased concentration of phenol was used to study the metabolic activity of mineralised activated sludge and B. laterosporus BT271. The CTC/DAPI staining showed high activity of the bacteria even at the highest concentration. The greatest amount of biomass was accumulated at 5 mg/l phenol (4.44 × 107 cells/ml). At this toxicant concentration, a total dehydrogenase activity of 5.72 × 10-4 μg H+/ml*min was found. Studies of the metabolic activity of microorganisms in experiments involving a combination of mineralised activated sludge, B. laterosporus BT271 and phenol at three concentrations (5 mg/l, 250 mg/l and 1000 mg/l) showed the highest value for dehydrogenase activity in the variant with average phenolic concentration (up to 6.39 × 10-6 μg H+/ml*min. The results proved the detoxification potential of B. laterosporus BT271 when different concentrations of phenol were present. The combination of a mineralised activated sludge and selected highly active biodegrading B. laterosporus BT271 showed valuable properties of detoxification and metabolic activity and keep these potentials up to 1000mg/l phenol. HTML XML PDF
      PubDate: Thu, 21 Apr 2022 19:00:15 +030
       
  • Natural zeolites as detoxifiers and modifiers of the biological effects of
           lead and cadmium in small rodents: A review

    • Abstract: BioRisk 17: 147-155
      DOI : 10.3897/biorisk.17.77435
      Authors : Michaela Beltcheva, Peter Ostoich, Iliana Aleksieva, Roumiana Metcheva : The present investigation analyzes the literature about the toxicity of Cd and Pb in small rodents’ organisms and the role of natural zeolites as modifiers of the biological effects. An array of ecotoxicological, morpho-physiological, hematological, genetic and biochemical methods as most representative are under discussion as a basic point for further exploration of biological effects in laboratory mice. The review of existing results demonstrated that there is abundant data on the sorption of lead and cadmium by modified natural zeolites in water and soils. Nevertheless, there is insufficient data on the ion exchange capacity and biological effects of this sorbent in living organisms, especially regarding Cd detoxification. On the basis of the current review, it is possible to conclude that future investigations in this field will elucidate the potential of the use of zeolites as successful detoxifiers against heavy metals and other toxic elements in living organisms. HTML XML PDF
      PubDate: Thu, 21 Apr 2022 19:00:14 +030
       
  • In vitro reconstitution of complexes of stress HliA protein with
           pigments

    • Abstract: BioRisk 17: 139-146
      DOI : 10.3897/biorisk.17.77306
      Authors : Lubov Sharapova, Nadezhda Yurina : Proteins similar to Hli (high light inducible) proteins of cyanobacteria are present in all photosynthetic eukaryotes and are necessary for survival in various stressful conditions, although their exact function is not fully understood. In current study, the recombinant stress-induced protein HliA of cyanobacterium Synechocystis was isolated and characterised for the first time. The synthetic gene of HliA protein was created and cloned into plasmid for expression of recombinant protein with Hisx6-tag at the C-terminus in bacteria. Recombinant HliA protein of Synechocystis was isolated by metal-affinity chromatography. The HliA protein was reconstituted with chlorophyll a and carotenoids. Using circular dichroism spectroscopy, it was shown that chlorophyll a and carotenoids interact in vitro with the HliA protein. The binding of pigments to the HliA protein favours the protective function of this protein. Apparently, Hli proteins are involved in the coordinated delivery of pigments for the biogenesis of photosynthetic complexes, thereby reducing the risk of accumulation of phototoxic free chlorophyll molecules. Current results are important for understanding the processes of photoprotection in either cyanobacteria or algae and higher plants. HTML XML PDF
      PubDate: Thu, 21 Apr 2022 19:00:13 +030
       
  • Cellular susceptibility and oxidative stress response to menadione of
           logarithmic, quiescent, and nonquiescent Saccharomyces cerevisiae cell
           populations

    • Abstract: BioRisk 17: 127-138
      DOI : 10.3897/biorisk.17.77320
      Authors : Polya Galinova Marinovska, Teodora Ivanova Todorova, Krassimir Plamenov Boyadzhiev, Emiliya Ivanova Pisareva, Anna Atanasova Tomova, Petya Nikolaeva Parvanova, Maria Dimitrova, Stephka Georgieva Chankova, Ventsislava Yankova Petrova : The aim of the present study was to compare cellular susceptibility and oxidative stress response of S. cerevisiae logarithmic (log), quiescent (Q), and non-quiescent (NQ) cell populations to menadione – a well-known inducer of oxidative stress. Three main approaches were used: microbiological – cell survival, molecular – constant field gel electrophoresis for detection of DNA double-strand breaks (DSB), and biochemical – measurement of reactive oxygen species (ROS) levels, oxidized proteins, lipid peroxidation, glutathione, superoxide dismutase (SOD) and catalase on S. cerevisiae haploid strain BY4741. The doses causing 20% (LD20) and 50% (LD50) lethality were calculated. The effect of menadione as a well-known oxidative stress inducer is compared in the log, Q, and NQ cells. Survival data reveal that Q cells are the most susceptible to menadione with LD50 corresponding to 9 µM menadione. On the other hand, dose-dependent DSB induction is found only in Q cells confirming the results shown above. No effect on DSBs levels is observed in log and NQ cells. Further, the oxidative stress response of the cell populations is clarified. Results show significantly higher levels of SOD and ROS in Q cells than in log cells after the treatment with 100 µM menadione. On the other side, higher induction of oxidized proteins, malondialdehyde, and glutathione is observed after menadione treatment of log cells. Our study provides evidence that Saccharomyces cerevisiae quiescent cells are the most susceptible to the menadione action. It might be suggested that the DNA damaging and genotoxic action of menadione in Saccharomyces cerevisiae quiescent cells could be related to ROS production. HTML XML PDF
      PubDate: Thu, 21 Apr 2022 19:00:12 +030
       
  • Comparative study on the oxidative stress of commercially important fish
           species from localities with different ecological conditions along the
           Bulgarian Black Sea coast

    • Abstract: BioRisk 17: 117-126
      DOI : 10.3897/biorisk.17.77300
      Authors : Albena Alexandrova, Yordan Raev, Dimitar Dimitrov, Nesho Chipev, Elina Tsvetanova, Almira Georgieva, Violin Raykov : The aim of the present study was to perform a pilot assessment and analysis of the oxidative stress (OS) level in four commercially important fish species (round goby, red mullet, sprat and horse mackerel) from different localities of the Bulgarian Black Sea coast. The fish were sampled during trawl selectivity experiments. The OS level in the fish was assessed by measuring lipid peroxidation (LPO), glutathione concentration (GSH), activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and glutathione-S-transferase (GST), as well as acetylcholine esterase (AChE) in gills and liver. Round goby and red mullet caught in the Nessebar Bay showed clear signs of OS with the highest levels of LPO and GST activities, accompanied by the lowest AChE activities in both liver and gills. On the contrary, round goby caught near Maslen Nos (a region with good ecological conditions) were least affected by OS with low LPO and high GSH concentrations and SOD activity. There were no significant differences in the OS bioindicators of horse mackerel from the different localities. Sprat caught in Nessebar Bay, compared to those caught from the other localities, showed presence of OS indicated by lower GSH levels and relatively higher CAT, GPx and GST activities, accompanied by low AChE activity in gills. It can be concluded that round goby and red mullet were more vulnerable to OS induced by marine environmental factors than the horse mackerel and sprat. However, their antioxidant defense system allows them to tolerate and adapt to the environment of their habitats. Further studies are needed for the assessment of OS in important fish species in the Bulgarian part of the Black Sea. HTML XML PDF
      PubDate: Thu, 21 Apr 2022 19:00:11 +030
       
  • Saccharomyces cerevisiae yeast cells as a test system for assessing Zeocin
           toxicity

    • Abstract: BioRisk 17: 105-116
      DOI : 10.3897/biorisk.17.77227
      Authors : Polya Marinovska, Teodora Todorova, Anna Tomova, Emiliya Pisareva, Krassimir Boyadzhiev, Martin Dimitrov, Petya Parvanova, Maria Dimitrova, Stephka Chankova, Ventsislava Petrova : Having unique genetic machinery and a high degree of conservation with higher eukaryotes, the yeast Saccharomyces cerevisiae is recognised as a smart experimental system for studying the modes of chemical toxicity. The present study was undertaken to elucidate the changes in the intracellular redox homeostasis and key macromolecule structure following exposure to Zeocin. Cell populations of logarithmic, quiescent (Q) and non-quiescent (NQ) cells of Saccharomyces cerevisiae BY4741 were used as a model to examine the cytotoxic effect of this radiomimetic. The levels of endogenous ROS, oxidized lipids, carbonylated proteins, and glutathione were analysed after treatment with Zeocin (IC50). An increase in ROS production and respectively increased oxidative stress was detected in all three types of cell populations, with the highest degree being observed in proliferating S. cerevisiae BY4741 cells. The stress response of both proliferating and stationary phase (Q and NQ) cells to Zeocin included an overexpression of glutathione. The quiescent cells also showed very low DNA susceptibility to high Zeocin concentration (100–300 µg/ml), presented as no induced double-strand breaks (DSBs) in the macromolecule. Based on our research it could be concluded that the cellular physiological state is a critical factor determining the resistance to environmental stress with Q cells being the most robust. HTML XML PDF
      PubDate: Thu, 21 Apr 2022 19:00:10 +030
       
  • Assessment of PAHs accumulation in Donax trunculus (Linnaeus, 1758)
           (Bivalvia, Donacidae) from the Bulgarian Black Sea Coast

    • Abstract: BioRisk 17: 95-104
      DOI : 10.3897/biorisk.17.77343
      Authors : Stanislava K. Georgieva, Mona D. Stancheva, Zlatina V. Peteva, Tsveteslava I. Ivanova, Albena V. Alexandrova : Anthropogenic pollution of marine ecosystems is one of the main sources of polycyclic aromatic hydrocarbons (PAHs). Marine bivalves are often used as bioindicators of environmental pollution due to their wide distribution and capability of xenobiotic bioaccumulation. The aim of the present study was to assess the presence of PAHs in soft tissues of wedge clams Donax trunculus (Linnaeus, 1758), collected from sublittoral sandy habitats at different locations off the Bulgarian Black Sea coast. Wedge clams from the different locations showed variations in the content of accumulated PAHs’ compounds. The concentrations of PAHs were measured by gas chromatography system with mass spectrometry detection. The total PAHs content (sum of 13 PAHs’ compounds) measured was in the range from 5.59 to 50.50 ng/g wet weight and was comparable with other European studies. The compounds phenanthrene and fluorene were most abundant in all analyzed samples. The results showed that low molecular weight (LMW) PAHs (2 and 3 aromatic rings) were predominant, accounting for 91% of the total PAHs levels, while high molecular weight (HMW) PAHs (4–5- and 6- rings) presence was 8.9% on average. The ratio LMW/HMW PAHs was higher than one, suggesting predominant pollution of petrogenic origin. The concentrations of benzo (a)pyrene did not exceed the limit set in EC Regulation although it was detected in 20% of the analyzed samples. In conclusion, maximum overall PAHs content was found in clams from Arkutino, while minimum PAHs content was present in samples from Elenite. The Sum PAH4 (sum of four polycyclic aromatic hydrocarbons: benzo[a]pyrene, chrisene, benzo[a]anthracene, and benzo[b]fluoranthene) in the wedge clams for all localities studied was below legislation limits. Data from the present research can be used for assessing pollution levels in the marine environment and also risk of human exposure to PAHs using D. trunculus as bioindicator species. HTML XML PDF
      PubDate: Thu, 21 Apr 2022 19:00:09 +030
       
  • Heavy metal stress response of microalgal strains Arthronema africanum and
           Coelastrella sp. BGV

    • Abstract: BioRisk 17: 83-94
      DOI : 10.3897/biorisk.17.77483
      Authors : Zornitsa Karcheva, Zhaneta Georgieva, Alexander Tomov, Detelina Petrova, Miroslava Zhiponova, Ivanina Vasileva, Ganka Chaneva : The present study compared the stress response of two microalgal strains – Arthronema africanum (Cyanoprokaryota) and Coelastrella sp. BGV (Chlorophyta), after heavy metals’ treatment. Changes of algal growth, pigment and protein content were analyzed after adding Cu, Cd and Pb (50 µM and 100 µM) to the nutrition medium. It was found that Cd and Pb significantly inhibited growth and protein biosynthesis of microalgae, but the effect of Cu remained less pronounced. In both strains, a decrease of chlorophyll content was observed, while carotenoid content markedly increased, especially in Coelastrella sp. BGV biomass. The addition of 100 µM Cd and 100 µM Pb to the medium caused a strong enhancement of malondialdehyde in both microalgal strains, which corresponded to the significant increase of superoxide dismutase and catalase activity. The antioxidant enzymes appeared to be differently altered by heavy metals’ exposure. The activity of SOD in the Arthronema africanum cells was most strongly affected by Cd, in contrast to Coelastrella sp. BGV that was highly increased by 100 µM Pb. The application of 100 µM Cd and 100 µM Pb increased in a similar manner catalase activity in both microalgae. The strains that were studied showed a high absorption capacity for metal ions, especially for Pb, which was absorbed largely than Cd and Cu. For that reason, we assumed that both microalga and, in particular, Coelastrella sp. BGV, could be successfully used for treatment of contaminated water bodies. HTML XML PDF
      PubDate: Thu, 21 Apr 2022 19:00:08 +030
       
  • Trace metal accumulation in tissues of wedge clams from sandy habitats
           of the Bulgarian Black Sea coast

    • Abstract: BioRisk 17: 73-81
      DOI : 10.3897/biorisk.17.77290
      Authors : Darina Bachvarova, Mona Stancheva, Tsveteslava Ignatova-Ivanova, Sevginar Ibryamova, Nesho Chipev, Albena Alexandrova : The aim of the present study was to carry out an initial screening of trace metals bioaccumulation in soft tissues of the wedge clam (Donax trunculus Linnaeus, 1758) from different localities of the Bulgarian Black Sea coastal area and to evaluate the bioindicator potential of this species. Wedge clams were collected in June and September 2020 from sublittoral sandy habitats at different localities of the Bulgarian Black Sea coast. Soft tissues of individual clams were digested with nitric acid followed by ICP-OES analytical determination. The content of trace metals in the wedge clams differed significantly amongst localities. Higher metal content was present in wedge clams from Sveti Vlas, Shkorpilovtsi, Slanchev Bryag, Ahtopol and Kranevo. The highest values of lead (Pb) (2.51 mg/kg) and cadmium (Cd) (0.32 mg/kg) were found in samples from Sveti Vlas and the highest concentration of copper (Cu) (34.12 mg/kg), iron (Fe) (269.52 mg/kg) and nickel (Ni) (0.32 mg/kg) were detected in wedge clams from Shkorpilovtzi. Maximum content of chromium (Cr) (0.58 mg/kg) was present in samples from Slanchev Bryag, together with high values of Fe. The highest concentration of zinc (Zn) (18.04 mg/kg) together with high values of Cr and Fe were measured in wedge clams from Irakli. In conclusion, the wedge clams from the localities known to have higher coastal inflows and touristic pressures, i.e. Varna, Shkorpilovtzi, Sveti Vlas, Slanchev Bryag and Ahtopol accumulated significantly higher metal elements in their tissues. Only few significant seasonal differences in the concentration of metal elements in wedge clams were present and the observed seasonal variations were probably connected to the hydrological parameters of the ecosystems. The wedge clam D. trunculus is a suitable bioindicator for assessment and monitoring of metal pollution in the Bulgarian Black Sea environment. HTML XML PDF
      PubDate: Thu, 21 Apr 2022 19:00:07 +030
       
  • Environmental impact assessment of discharge of treated wastewater
           effluent in Upper Iskar sub-catchment

    • Abstract: BioRisk 17: 59-71
      DOI : 10.3897/biorisk.17.77381
      Authors : Veronika Yordanova, Yovana Todorova, Mihaela Belouhova, Lyubomir Kenderov, Valentina Lyubomirova, Yana Topalova : The upper Iskar sub-catchment is one of Bulgaria’s most important economic and socially significant water sources because of its role in supplying Sofia with drinking water. Among the critical factors that carry potential high-risk levels for water quality in this hydrosystem are the discharge from the Samokov Wastewater Treatment Plant (WWTP), diffuse pollution from agriculture, and the percolation of untreated sewage from the small villages. In this study, we assessed the effect of treated wastewater effluent on water quality, and on the ecological state and microbial communities in the river sector of Samokov’s WWTP discharge area. The assessment was based on the complex use of chemical and microbiological indicators and biological quality elements. The concentrations of organics, nutrients and microcomponents were determined with results confirming the expected increase for parameters associated with the discharge of urban wastewater. The ecological state, according to macrozoobenthos indicators, was “good” throughout the river sector but local deterioration was registered in a proximal location downstream of the WWTP outfall. The analysis of stream water and bed sediment microbial communities by a fluorescent technique showed the high metabolic activity and intensive transformation processes in addition to high abundance registered with standard cultivation methods. The importance of the studied sub-catchment for the functioning of the urban water cycle, and for the quality of Sofia’s drinking water, underlines the need to extend an existing monitoring program with a more detailed assessment of the environmental impact of wastewater discharge. HTML XML PDF
      PubDate: Thu, 21 Apr 2022 19:00:06 +030
       
  • Radiation status of soils from the region of the Eastern Rhodopes
           (Southern Bulgaria)

    • Abstract: BioRisk 17: 45-57
      DOI : 10.3897/biorisk.17.77432
      Authors : Milena Hristozova, Radoslava Lazarova : Local values of natural radiation background in soils from unexplored regions in the Eastern Rhodopes were established. The impact of anthropogenic activity as a potential risk for increase in radiation background was assessed. Soil samples from areas near the liquidated lead-zinc mines – Madzharovo, gold mine – Ada Tepe, Krumovgrad, lead-zinc complex – Kardzhali, Neochim – Dimitrovgrad, deposits for extraction of gneiss, marble quarries, etc. were analyzed to study possible contamination. Specific activity of natural radionuclides 210Pb, 238U, 226Ra, 235U, 232Th, 40K and technogenic 137Cs in the studied samples was determined by gamma spectrometric analysis with Multichannel analyzer DSA 1000, production of CANBERRA and HPGe-detector. HTML XML PDF
      PubDate: Thu, 21 Apr 2022 19:00:05 +030
       
  • Differences in bacterial functional profiles from loamy sand and clay loam
           textured soils under fungicide QuadrisR impact

    • Abstract: BioRisk 17: 31-43
      DOI : 10.3897/biorisk.17.76939
      Authors : Michaella Petkova, Anelia Kenarova, Silvena Boteva, Stela Georgieva, Christo Chanev, Galina Radeva : The non-target effect of the fungicide QuadrisR on the bacterial community from grassland loamy sand (LS) and cropland clay loam (CL) soils with unknown history of fungicide usage was investigated. QuadrisR was applied to soil mesocosms at 0.0 mg kg-1 (Az0), 2.90 mg kg-1 (Az1), 14.65 mg kg-1 (Az2) and 35.0 mg kg-1 (Az3) calculated towards the active ingredient azoxystrobin (Az). Response of bacterial communities to QuadrisR was investigated during a 120-day incubation experiment, evaluating the shifts in bacterial catabolic profiles by the community-level physiological profiling (CLPP) technique and Biolog EcoPlatesTM method. QuadrisR decreased the overall catabolic activity (AWCD) of soil bacterial communities and the rate of decrease was independent of soil type and fungicide concentration. Fungicide affected negatively the utilisation of amines and positively that of amino acids in both soil types, whereas the effects on other carbon guilds (carbohydrates, carboxylic acids and polymers) corresponded closely to the respective soil type and fungicide concentration. Results indicated the presence of non-target effects of QuadrisR on bacterial functioning; hence, it is important to address the fungicide side-effects on soil health. HTML XML PDF
      PubDate: Thu, 21 Apr 2022 19:00:04 +030
       
  • Correlation between bacterial abundance, soil properties and heavy
           metal contamination in the area of non-ferrous metal processing plant,
           Southern Bulgaria

    • Abstract: BioRisk 17: 19-30
      DOI : 10.3897/biorisk.17.77458
      Authors : Radina Nikolova, Michaella Petkova, Nikolai Dinev, Anelia Kenarova, Silvena Boteva, Dimitar Berov, Galina Radeva : In the present study, the correlation between bacterial abundance and soil physicochemical properties along the heavy metal contamination gradient in the area of non-ferrous metal processing plant was assessed. Our results showed that bacterial abundance (number of heterotrophic bacteria and number of 16S rRNA gene copies) decreased with 45–56% (CFU) and 54–87% (16S rRNA gene) along the Zn, Pb and Cd contamination gradient. The total bacterial abundance (16S rRNA gene) increased exponentially in contrast to the abundance of heterotrophic bacteria. The reduction of bacterial abundance in heavily contaminated soil indicated that the soil properties (soil pH, total organic carbon, inorganic ions, soil texture) could modify the effects of heavy metals and the response of microorganisms to that stress in long-term contaminated soils. HTML XML PDF
      PubDate: Thu, 21 Apr 2022 19:00:03 +030
       
  • Ecocide – global consequences (pesticides, radionuclides, petroleum
           products)

    • Abstract: BioRisk 17: 7-18
      DOI : 10.3897/biorisk.17.77438
      Authors : Roumiana Metcheva, Peter Ostoich, Michaela Beltcheva : The problem of environmental pollution is becoming increasingly important on a global scale. Man has oversaturated the environment of his habitat with harmful and most often toxic waste. It is difficult to describe all the toxic substances, as a separate book can be written for each group. The term “ecocide” has been introduced, which reflects large-scale destruction of the natural environment. We will focus only on three classes of pollutants that are of particular concern, creating environmental conflicts. These are: • Pesticides are extremely toxic and create large amounts of non-degradable waste. It accumulates in tissues and organs of target organisms, becoming toxic and causing serious pathological changes in the body, mainly at the cellular and subcellular levels, causing various diseases and as a result, serious changes in the structure and functions of the populations and the whole ecosystem are increasingly observed. • Waste from the nuclear industry and radioactive fallout from nuclear explosions. It is especially dangerous that radioactive elements can be concentrated in certain organs. • Petroleum products - often large quantities end up in the seas and oceans, along with industrial waste of various kinds, impossible to compensate for by nature and they pose a serious threat to ecosystems, many of which have already been destroyed. At the submolecular level, chemical and physical effects can lead to genetic rearrangements (mutations); destructive ionization in the tissues of every living being, sometimes with completely unexpected consequences for humans. HTML XML PDF
      PubDate: Thu, 21 Apr 2022 19:00:02 +030
       
  • International seminar of ecology – 2021 “Current trends of
           ecology”

    • Abstract: BioRisk 17: 1-5
      DOI : 10.3897/biorisk.17.84978
      Authors : Stephka Chankova : none HTML XML PDF
      PubDate: Thu, 21 Apr 2022 19:00:01 +030
       
  • Citizen scientists significantly improve our knowledge on the non-native
           longhorn beetle Chlorophorus annularis (Fabricius, 1787) (Coleoptera,
           Cerambycidae) in Europe

    • Abstract: BioRisk 16: 1-13
      DOI : 10.3897/biorisk.16.61099
      Authors : Matthias Seidel, Maren Lüttke, Christian Cocquempot, Katy Potts, Wil J. Heeney, Martin Husemann : The Asian bamboo borer Chlorophorus annularis is a beetle species that has been introduced in many countries globally. Originating in Southeast Asia, it can now be found in the Americas, South Africa, the Middle East, Australasia and Europe. The literature record of the species in Europe consists of findings of single individuals usually associated with imported bamboo products. A general European effort in surveying C. annularis was never undertaken, since the overall scientific consensus was that the species cannot establish here. Yet, recent records in Genk, Torhout (Belgium) and in Hamburg (Germany) do not seem directly associated with a recently imported product and hence may indicate otherwise. Such a shortfall in recording commonly imported, potentially invasive species may be counteracted through citizen science initiatives, allowing for continuous, high density monitoring. In this paper we present thirteen new records of the species from five European countries, including two new country records, mostly going back to interested citizen scientists. HTML XML PDF
      PubDate: Tue, 9 Mar 2021 16:44:00 +0200
       
 
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