Authors:Kinsley Meg G. Perez, Julius A. Parcon, Emmanuel Ryan C. de Chavez Abstract: Prior to this study, there had been no malacofaunal study in the University of the Philippines Laguna Land Grant (UPLLG). To address this, a diversity survey of its freshwater and land mollusks was conducted. A total of 25 quadrats (15 m2) on upstream and downstream stations along Dakil River and its tributaries for freshwater mollusks and 12 quadrats (100 m2) for land snails were set randomly to correlate their diversity patterns with environmental variables. From 115 individuals of freshwater mollusks, seven species (six gastropods, one bivalve) belonging to six families (Ampullariidae, Corbiculidae, Lymnaeidae, Neritinidae, Thiaridae, and Viviparidae) were identified. On the other hand, seven species belonging to three families (Ariophantidae, Camaenidae, and Chronidae) were identified among 28 land snail individuals. Malacofaunal survey revealed that the area along Dakil River has low diversity in both freshwater mollusk (H’=1.40) and land snail (H’=1.19). Generalized linear mixed models (GLMM) revealed river velocity was the most significant predictor for species richness of freshwater mollusks, and abundance was highly affected by temperature and inversely affected by canopy cover. Furthermore, altitude was the most significant predictor for species richness of land snails and canopy cover for abundance. Understanding the molluscan diversity could help determine the environment and ecological conditions of the watershed for its effective management and conservation. PubDate: 2022-04-28 Issue No:Vol. 33, No. 2 (2022)
Authors:Gil M. Penuliar, Renz Joseph R. Artezuela Abstract: Fructophilic lactic acid bacteria (FLAB) is a recently discovered group of lactic acid bacteria that prefers fructose as carbohydrate source. The isolation of FLAB from fructose-rich niches like flowers, in particular, and the gut of insect pollinators suggests that it may be used as probiotics. The objective of this study was to determine if FLAB can be isolated from flowers at the Institute of Biology, University of the Philippines Diliman, and to screen them for antimicrobial activity against bacteria that are commonly associated with intestinal diseases. A total of 20 different isolates were obtained from 14 species of flowers. All isolates were identified as LAB, but only 17 out of 18 isolates were osmotolerant in 30% fructose, and only 8 out of 15 isolates had higher absorbance in Fructose Yeast Peptone Broth, which are characteristics of presumptive FLAB. Seven isolates exhibited inhibitory activity in at least three test bacteria in the primary screening and only four isolates had inhibitory activity in at least two test bacteria, particularly against Enterococcus faecalis and Campylobacter jejuni, in the secondary screening. DNA sequencing and phylogenetic analysis identified isolates MFPS 4.1 and MFRU 7.2 as Weissella spp. The in vitro antimicrobial activities of these isolates can be studied further for possible applications in food and medicine, and their low sequence similarities suggest that the isolates might be novel Weissella species. PubDate: 2022-04-28 Issue No:Vol. 33, No. 2 (2022)
Authors:Michael R. Noel+, Edna A. Aguilar, Alangelico O. San Pascual Abstract: Papaya plants (Carica papaya L.) were assessed for tree and fruit morphological traits. During eight months of drought conditions, papaya plants showed signs of drought from March to May 2016. Drought affected fruit development and fruit qualities. Significant decrease in fruit weight, length, width, flesh thickness, and seed weight were observed in drought-affected papayas; however, total soluble solids (TSS) of fruit flesh were significantly higher compared to the TSS of fruits harvested during normal conditions. Drought-tolerant papaya trees were selected based on morphological responses. Drought-tolerant papaya trees were significantly taller and had thicker stems, wider crowns, and more functional green leaves compared to drought-affected trees. Selected plants that thrived well under drought condition were identified for use in breeding. Recovery of plants was evident in increase in fruit weight, length, and width. Correlation of fruit characters of selected drought-tolerant papaya trees revealed that fruit weight was strongly positively correlated with fruit length, fruit width, peel weight, flesh thickness, and TSS. PubDate: 2022-04-28 Issue No:Vol. 33, No. 2 (2022)
Authors:Marte C. Villena, Mona B. Antivola, Janelle Stephanie M. Torrefiel, Rheo B. Lamorena-Lim Abstract: The study of the spectroscopy of solid materials is not as extensive compared to that of homogeneous liquid solutions. Optical properties, such as reflectance, transmittance, and absorbance, may be used for the characterization of new materials. Qualitative characterization of colored materials and quantitative determination of surface modification and band gap analysis through the Tauc plot method were obtained using visible-reflectance spectroscopy. Differentiation of reflectance peaks was observed in the spectra of colored papers and acrylic spray paints. Expected trends of higher reflectance according to the ability of a color to reflect light were also observed. Surface analysis through the reflectance method indicated that spectra of pristine and surface-modified samples showed a significant difference in signals, which is attributed to the roughening and contamination of the surface of the materials. Using the Tauc plot method on the absorbance spectrum data of an electrodeposited zinc oxide film, the calculated BGE was 3.80 eV, with a 15.15% deviation from its literature value of 3.30 eV. In addition, zinc sulfide, which was chemically deposited on glass slides, had an average band gap of 3.0 eV, with an 8.82% error against its literature value of 3.4 eV. These experiments on specular reflectance of solid materials, particularly optical and new materials, may be incorporated in undergraduate laboratory courses. PubDate: 2022-04-28 Issue No:Vol. 33, No. 2 (2022)
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