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Ethiopian Journal of Sciences and Sustainable Development
Number of Followers: 0  

  This is an Open Access Journal Open Access journal
ISSN (Print) 1998-0531 - ISSN (Online) 2663-3205
Published by Adama Science and Technology University Homepage  [1 journal]
  • Chemical Constituents of the Roots Extract of Dryopteris schimperiana and
           Evaluation for Antibacterial and Radical Scavenging Activities

    • Authors: Bayan Abdi, Emebet Getaneh, Temesgen Assefa, Aman Dekebo, Hailemichael Tesso, Teshome Abdo, Yadessa Melaku Ayana
      Pages: 1 - 8
      Abstract: Dryopteris schimperiana (Dryopteridaceae) is traditionally used in folk medicine of Ethiopia against bacteria and internal parasites. In view of its traditional use and absence of scientific reports, an attempt was made to explore the chemical constituents, antibacterial and radical scavenging activities of the solvent extracts of the root of Dryopteris schimperiana. In this regard, the root was successively extracted with n-hexane, CHCl3 and methanol to afford 5 g (2%), 2 g (0.8%) and 26.6 g (10.6%), respectively. The n-hexane and CHCl3 extracts showing similar TLC profile were mixed and fractionated over silica gel column chromatography which led to the isolation of two compounds identified as heptacosanol (1) and isorhmentin (2). The structures of the isolated compounds were accomplished using spectroscopic methods including UV-Vis, IR and NMR. To the best of our knowledge, these compounds have not been reported from the genus Dryopteries. The extracts and isolated compounds were evaluated for their antibacterial activities using agar well diffusion method against two Gram-positive bacteria (Staphylococcus aureus and Bacillus subtitis) and two Gram-negative bacteria (E. coli and Salmonella). The results showed that the n-hexane extract, methanol extracts and isolated compounds were active against all tested bacteria, with compound 2 shown to have an inhibition zone of 17 mm which is comparable with the positive control. Furthermore the extracts and isolated compounds were assessed for their radical scavenging activity using DPPH assay. Isorhmentin (2) displayed pronounceable % radical scavenging activity (82.8%) compared with ascorbic acid indicating its strong ability to act as radical scavenger. This study demonstrated that the antibacterial and radical scavenging activity of the root of D. shimperiana is accounted to the presence of isorhamnetin. Therefore, the biological activity displayed by the constituents of the roots of D. shimperiana corroborates the traditional use of this plant against bacteria.
      Key words: Dryopteris schimperiana, NMR, antibacterial activity, antioxidant
      PubDate: 2020-01-06
      DOI: 10.20372/ejssdastu:v7.i1.2020.153
      Issue No: Vol. 7, No. 1 (2020)
       
  • Isolation of Cellulose Degrading Bacteria from Rumen and Evaluation of
           Cellulase Production by the Isolate Using Lignocellulosic Substrate

    • Authors: Olyad Erba Urgessa, Yimeslal Atnafu Sima, Mahafuz Mohammed Adem, Ameha Kebede Ayele
      Pages: 8 - 17
      Abstract: The utilization of cheaper substrates reduces cost of cellulase production and there is the need for cellulolytic microbes capable of degrading lignocellulosic materials. Therefore, this study was aimed to isolate and identify bacteria from rumen fluid, and evaluate wheat straw, sorghum straw and bagasse for cellulase production. Rumen fluid were collected from cattle, goat and sheep slaughtered at Haramaya town abattoir. Wheat and sorghum straw, and bagasse were obtained from Haramaya University research plot and Wonji-Shewa Sugar Factory, respectively. One-way analysis of variance (ANOVA) was used for data analysis using SPSS version 20. Microscopic and Biochemical tests of potential cellulase producers were carried on Luria Bertoni Agar enriched with 1% Carboxymethyl cellulose of sodium (CMC-Na). Cellulase production was evaluated using submerged fermentation. The potential CMC degrading isolate (HUG-3b) and (HUS-2a) from goat and sheep rumen fluids, respectively, were identified as Pseudomonas sp. and isolate (HUC-4b) from cattle rumen fluid was identified as Aeromonas sp. Pseudomonas sp from goat rumen produced significantly the highest carboxymethyl-cellulase (CMCase) and filter-paperase (FPase) of 1.54 ± 0.10 U/ml, 1.46 ± 0.09 U/ml from fermentation of 1% w/v Carboxymethyl cellulose used as standard and 1% wheat straw, respectively (p < 0.05), whereas, Pseudomonas sp. from sheep rumen produced significantly the highest CMCase of 1.81 ± 0.27 U/ml from fermentation of 1% wheat straw(p < 0.05) and insignificantly highest FPase of 1.27 ± 0.22 U/ml from fermentation of 1% bagasse(p > 0.05). Aeromonas sp. produced insignificantly the highest CMCase and FPase of 2.31 ± 0.17 U/ml, 1.50 ± 0.02 U/ml from fermentation of 1% and 2% wheat straw, respectively (p > 0.05). It can be concluded that the fermentation of 1% and 2% wheat straw by Aeromonas can be utilized for the maximum production of cellulase.  Identification of the species or strain of isolate using molecular technique will be recommended.  
      PubDate: 2020-01-06
      DOI: 10.20372/ejssdastu:v7.i1.2020.127
      Issue No: Vol. 7, No. 1 (2020)
       
  • PREDICTIONS OF CLIMATE CHANGE ON AGRICULTURAL INSECT PESTS VIS-Ă€-VIS FOOD
           CROP PRODUCTIVITY: A CRITICAL REVIEW

    • Authors: Daniel Getahun
      Pages: 18 - 26
      Abstract: Climate change is a broad range of global phenomena created predominantly by burning fossil fuels, which add heat-trapping gases called greenhouse gases to Earth’s atmosphere. Insects are poikilothermic animals and thus sensitive to climate warming. Global warming and climate change will trigger major changes in diversity and abundance of arthropods, geographical distribution of insect pests, population dynamics, insect biotypes, herbivore plant interactions, activity and abundance of natural enemies, species extinction, and efficacy of crop protection technologies. Climate change also will have severe impacts on insects, especially honeybees, which pollinate crop plants and thus affect crop production highly. Combined effects of these will increase the extent of crop losses, and thus, will have a major bearing on crop production and food security. Prediction of changes in geographical distribution and population dynamics of insect pests will be useful for adapting pest management strategies to mitigate the adverse effects of climate change on crop production. This paper summarized the different ways in which climate change impacts on insect pests and will increase the extent of crop losses. Governments should respond to climate change both by reducing the rate and magnitude of change by reducing greenhouse gas emissions (mitigation), and by adapting to its impacts. Many impacts can be avoided, reduced or delayed by mitigation, but adaptation will be necessary to address impacts resulting from the warming which is already unavoidable due to past emissions. Therefore, there is a need to take a concerted look at the likely effects of climate change on crop protection and devise appropriate measures to mitigate the effects of climate change on food security.
      PubDate: 2020-01-06
      DOI: 10.20372/ejssdastu:v7.i1.2020.128
      Issue No: Vol. 7, No. 1 (2020)
       
  • Antibacterial steroids from roots of Bersama abyssinica

    • Authors: Fitsum Lemilemu, Solomon Girmay, Kebede Shenkute, Milkyas Endale
      Pages: 27 - 34
      Abstract: Bersama abyssinica is one of the medicinal plants used traditionally to treat various diseases such as leprosy, wound, diarrhea, fever, eye disease, rabies and tumor/cancer. Phytochemical screening test of dichloromethane/methanol (1:1) and methanol extracts revealed the presence of glycosides, alkaloids, tannins, flavanoids, saponins, terpenoids, steroids and phytosterols. Silica gel column chromatography separation of dichloromethane/methanol (1:1) root extracts afforded β-sitosterol (1), 7-hydroxysitosterol (2) and 2-methylamino-butyric acid (3) of which the latter is isolated for the first time from natural source. The crude extracts and isolated compounds were screened for in vitro antibacterial activity against strains of Salmonella thphimurium, Escherichia coli, Bacillus subtilis and Staphylococcus aureus. Dichloromethane/methanol (1:1) extract, methanol extract and β-sitosterol (1) showed moderate activity against E. coli and S. aureus (zone of inhibition 13±0, 13±2 and 12.6±0.48, respectively) and (zone of inhibition 13.6±0.55, 12±2, and 12.5±0.5 mm, respectively) compared to ciprofloxacin (28.6±1.25 and 26±5.1 mm) at 0.5 mg/mL. The structures of compounds were determined by spectroscopic techniques (IR and NMR) and comparison with literature report.
      PubDate: 2020-01-10
      DOI: 10.20372/ejssdastu:v7.i1.2020.156
      Issue No: Vol. 7, No. 1 (2020)
       
  • Investigation of Laser Surface Treatment on the Microstructure and
           Mechanical Properties of AlSiMn Alloy

    • Authors: Moera Gutu, Habtamu Beri Tufa
      Pages: 35 - 43
      Abstract: This work investigates high-temperature properties of AlSiMn alloy after laser remelting by continuous mode CO2 laser energy. Substrate materials were prepared after solutionized heat- treated at 510oC for 5 h followed by artificially aged at 160oC for six hours. The result of the finding showed high improvement in mechanical properties by 80% of heat-treated samples. The formation of fine dendrite microstructure, rode like larger secondary dendrite and sound metallurgical bonded morphology played a great role. The maximum laser modified thickness of 2.23 mm was achieved.
      PubDate: 2020-01-10
      DOI: 10.20372/ejssdastu:v7.i1.2020.134
      Issue No: Vol. 7, No. 1 (2020)
       
  • Determination of Residue Levels of DDT and Its Metabolites in Khat and
           Cabbage Samples using QuEChERS Sample Preparation Method Combined with
           GC-MS Detection

    • Authors: Chala Regassa, Teshome Tolcha, Kefyalew Gomoro, Negussie Megersa
      Pages: 44 - 53
      Abstract: A  simple and selective quick, easy, cheap, effective, rugged and safe (QuEChERS) extraction technique coupled with gas chromatography mass spectrometric detection (GC-MS) was developed and validated for simultaneous determination of 1,1,1-trichloro-2,2-di(4-chlorophenyl)ethane (p,p'-DDT) and its main metabolite 1,1-dichloro-2,2-bis(4-chlorophenyl) ethylene(p,p'-DDE) and 1,1-dichloro-2,2-bis(4-chlorophenyl) ethane (p,p'-DDD) in cabbage and Khat samples. The linearity of the analytical response was acceptable with correlation coefficients of 0.992 or better. The precision associated with the analytical method, expressed as %RSD were lower than 8.6 and 9.1% for the intraday and interday precision, respectively.The limit of detection (LOD) and limit of quantification (LOQ) of the proposed method for cabbage sample were in the range of 0.023–0.04 mg/kg and 0.09–0.14 mg/kg respectively. The LOD and LOQ of the proposed method for Khat sample were in the range of 0.02–0.06 mg/kg and 0.07–0.19 mg/kg respectively. The LOD and LOQ of the method were below the maximum residue level set by European Commission for the pesticides in both samples. The recoveries of the method were ranging from 97.16 to 107.99 for cabbage and 72.1 to 90.55 for Khat sample. The analytical applications of this method indicates the presence of p,p'-DDE, p,p'-DDD and p,p'-DDT in both cabbage and Khat samples.
      PubDate: 2020-01-10
      DOI: 10.20372/ejssdastu:v7.i1.2020.119
      Issue No: Vol. 7, No. 1 (2020)
       
  • SCREENING OF SOME BOTANICAL INSECTICIDES AGAINST MAIZE WEEVIL, SITOPHILUS
           ZEAMAIS MOTSCH. (COLEOPTERA: CURCULIONIDAE), ON MAIZE

    • Authors: Daniel Getahun, Mulatwa Wondimu
      Pages: 54 - 62
      Abstract: Maize is one of the major cereal crops grown for food in Ethiopia and the maize weevil, Sitophilus zeamais is a major insect pest of stored maize. Controlling of the pest by use of synthetic insecticides is raising serious concern on the environmental safety, consumer health hazards and high costs for subsistence farmers and thus there is a need to develop alternative safe and cheap methods of insect control strategies such as the use of insecticidal botanicals against the storage pest. The aim of this study was to evaluate the efficacy of powders of seeds of Azadrichta indica, Millettia ferruginea and Jatropha curcas, leaves of Croton macrostachyus and Euphorbia schimperiana and to screen the minimum effective dose of each botanical for the management of maize weevil. The plant materials were collected air-dried under shade, ground separately into a fine powder using micro plant grinding machine. Three, four, and five grams of powder of each botanical were added to each 100 g of clean maize in each 250 cm3 glass jar and mixed uniformly by shaking. A standard insecticide, Pirimiphos-methyl 2 % dust (2 g) and untreated check were included for comparison. Twenty-six newly unsexed emerged adult weevils were placed in each jar and covered with muslin cloth. The treatments were arranged in completely randomized design (RCD) with three replications. Weevil mortality was recorded at 3, 7, 14, 21, and 28 days after initial infestation. During the last counting, both dead and alive weevils were counted and removed and the grains were kept under the same conditions for the emergence of F1 generation. The numbers of F1 progeny weevils emerging were recorded every other day for 33 days. Seed germination was tested using 15 randomly picked seed from undamaged grains from each jar. A significant difference (P < 0.05) was observed between all the botanicals at all rates and the untreated control three to 28 days after treatment. The cumulative mortality 28 days after infestation was very high (97.43 –100%) and there was no significant difference between all the botanicals at all rates and the standard chemical. No significant difference was observed (P > 0.05) in the number of emerged F1 among the botanical treatments and the chemical insecticide, but significant difference was recorded between these treatments and the control at 1 and 2 days and cumulative emerged progeny after 28 days. Seed germination test generally revealed over 77 seed viability and no significant difference was found among all the treatments. The study revealed that the botanicals can be used as components of maize weevil management options as they caused high weevil mortality and very low fecundity and showed insignificant effect on seed viability. However, the impacts of consumption of the botanically treated maize on humans need further study.  
      PubDate: 2020-01-10
      DOI: 10.20372/ejssdastu:v7.i1.2020.149
      Issue No: Vol. 7, No. 1 (2020)
       
  • Households’ Willingness to Pay for Livestock Insurance in Karrayyu
           Pastoralist Community: An Attempt for Risk Reduction.

    • Authors: Jeleta Gezahegne Kebede, Birku Reta Entele, Alemayehu Ethiopia Derege
      Pages: 63 - 78
      Abstract: The study aim to investigate pastoralist community’s willingness to pay (WTP) and factors that determine their willingness to pay for index based livestock insurance scheme. Using survey data collected by systematic sampling method, the study adopted an interval data logit model and estimated households’ WTP for index based livestock insurance for camels, cattle and goats & sheep’s separately. The study finding reveals that there is huge demand for livestock insurance scheme following recurrent drought and increased chance of losing their livestock. The estimated result shows that total WTP for camel, cattle and goat and sheep is about 2.7, 4.27, and 4.4 million birr per year respectively. Age of household head, family size, number of camel size and value of household asset have significant positive effect; where as  non-farm income and distance from local market have negative effect on households’ probability of joining Camel insurance. The cattle model shows that value of household assets have negative effect and size of the cattle has positive effect on the probability of households’ willingness to join cattle insurance and their WTP. The goat and sheep model shows that number of goat and sheep has positive effect; income from livestock and age of household head has negative effect on households’ probability of joining livestock insurance and WTP.  In all models, the starting bid price has negative significant effect on the demand for livestock insurance, confirming the law of demand. Policy suggestion is that public or private insurance company can intervene through supply of livestock insurance for commercial purposes as well as to mitigate the side effect of covariate shocks leading to smooth consumption and stable income stream of households. Preferential policy intervention for camel insurance may yield better outcome as the community gives more value to the camel.
      PubDate: 2020-01-15
      DOI: 10.20372/ejssdastu:v7.i1.2020.114
      Issue No: Vol. 7, No. 1 (2020)
       
  • Combination of Organic and Inorganic Fertilizer Improves Tef (Eragrostis
           tef) Yield and Yield Components and Soil Properties on Nitisols in the,
           Central Highlands of Ethiopia

    • Authors: Girma Chala Tulu
      Pages: 79 - 87
      Abstract: A field experiment was made to evaluate combination of organic and inorganic fertilizers on yield and yield components of tef and soil properties. The study was conducted for three consecutive cropping seasons (2015-2017) on farmers’ fields in Welmera district of Oromiya Regional State. The objective of this study was to evaluate the response of organic and inorganic nutrient source on growth and yield of tef under balanced fertilizers. The treatments included eleven selected combinations of organic and inorganic nutrient sources (Farm yard manure, Compost, Nitrogen and Phosphorus). The design was randomized complete block with three replications. Results revealed that tef yield and yield components were significantly affected by the application of organic and inorganic fertilizer sources. The highest tef grain yield (2042.6 kgha-1) was obtained from the applications of 25% compost with 75% recommended nitrogen and phosphorus fertilizer. While, highest biomass yield (8535.4 kgha-1) was obtained from the applications of full doses of recommended N and phosphorus fertilizers. Application of the different organic fertilizers improves the organic matter, Total N, available P and pH of the soil in the study area. The result also showed that the highest marginal rate of return was obtained from application of 50% FYM (farm yard manure) + 50% recommended nitrogen and phosphorus fertilizer, which is economically the most feasible alternative for tef production on nitisols of central Ethiopian highlands. Therefore, based on the MMR application of 50% FYM (farm yard manure) + 50% recommended nitrogen and phosphorus fertilizer can be recommended for tef production for the study areas.
      PubDate: 2020-02-05
      DOI: 10.20372/ejssdastu:v7.i1.2020.145
      Issue No: Vol. 7, No. 1 (2020)
       
 
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