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UPV Theses and Dissertations

Permanent URI for this communityhttps://hdl.handle.net/20.500.14583/10

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Adviser: search.filters.advisor.Sabada, Resurreccion B.Committee Chair: search.filters.chair.Nievales, Marie Frances P.

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    Antimicrobial activity of macrofungal basidiomycetous mycelia against Vibrio spp.
    Bagacay, Jann Felnesh Exe V. (Division of Biological Sciences, College of Arts and Sciences, University of the Philippines Visayas, 2023-06)
    Aquaculture is vital for global food security, producing 50% of the world’s fish. However, infectious diseases caused by fish pathogens like Vibrio species can lead to significant production losses. To address this issue, antimicrobial agents are commonly used. Macrofungal fruiting bodies and mycelia produce bioactive compounds with antimicrobial properties. This study aims to: (a) assess antimicrobial activity in isolated macrofungal samples against the fish bacterial pathogens Vibrio parahaemolyticus and Vibrio cholerae, (b) compare two methods (agar plug and crude extracts) for antimicrobial activity, (c) determine the minimum inhibitory concentration (MIC) using agar well diffusion and the agar plug methods, and (d) identify the macrofungal isolate with the highest antimicrobial activity. Ten morphospecies were collected from the University of the Philippines Visayas Miagao Campus. The samples were evaluated using the agar plug and agar well diffusion methods. The results showed antimicrobial activity against Vibrio cholerae and Vibrio parahaemolyticus. The activity index ranged from 0 to 0.83 and 0.22 to 0.78 for agar wells, and 0 to 1.00 and 0.70 to 1.30 for agar plugs, against V cholerae and V. parahaemolyticus, respectively. Termitomyces globulus and Trametes sp. 1 exhibited the highest activity indices using the agar plug and agar well diffusion methods, respectively. Statistical analysis confirmed significant differences in antimicrobial activity against both test organisms. These findings demonstrate the potential of macrofungi as a valuable source of antimicrobial compounds for controlling fish pathogens in aquaculture. Further research could lead to the identification and utilization of these compounds to minimize production losses and improve disease management in aquaculture.
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    Assessment of damage to mangroves in Taklong Island National Marine Reserve, Guimaras, Philippines: 10 years after the 2006 oil spill
    Amistas, Jhon Robert (Division of Biological Sciences, College of Arts and Sciences, University of the Philippines Visayas, 2017-06)
    Approximately 2 million liters of bunker C was spilled by M/T Solar I off the coast of southern Guimaras on August 11, 2006. This is the worst oil spill in the country to date that affected the mangroves within Taklong Island National Marine Reserve, Nueva Valencia, Guimaras. Rapid assessment of impacts on the mangroves was done one month after the spill and long-term monitoring was done from 2007-2014. This study was conducted to determine the mangrove status 10 years after the spill in terms of community structure. Specifically, it determined a) species composition, b) stand basal area, c) stand height, d) relative density, e) relative dominance, e) relative frequency, f) importance value, g) index of diversity, h) species evenness, i) density of seedling, saplings, and trees. In addition, leaf area was also determined as an indicator of the health conditions of the species present. The same five stations in earlier studies were used, namely Bagaman, Pototan, Taklong Island (oiled), Tandog and Taklong Island (unoiled), Nueva Valencia, and Guimaras. Results showed that the community structure showed an improvement, especially in stand, basal area, wilding, and tree density while no change in terms of species diversity due to the absence of new species. The leaf areas of mangroves in Bagatnan indicated some signs of stress but showed an improvement since 2006. In general, the oil-affected mangroves in TINMR have shown signs of recovery. However, it is recommended that additional monitoring activities be conducted.
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    Inhibition of bacterial Biofilm formation by selected wild Macrofungi from Miagao, Iloilo
    Anacita, Beatrice L. (Division of Biological Sciences, College of Arts and Sciences, University of the Philippines Visayas, 2023-07)
    Biofilms are complex bacterial communities with high-stress tolerance and antimicrobial resistance, posing a global health concern. Mushrooms are known for their bioactive compounds, including antimicrobial properties, and may offer a solution for inhibiting biofilm formation. This study investigates the biofilm inhibition activity of wild macrofungi collected in Miagao, Iloilo. Five basidiomycetous macrofungi—Panaeolus sp., Chlorophyllum hortense, Lentinus concavus, Hexagonia hydnoides, and Daedalea sp.—were characterized. Bacterial strains were treated with equal concentrations of ethanolic mycelial extracts from the macrofungi samples and evaluated for adherence and inhibition percentage using a microtiter plate assay at 37°C for 72 hours. The results showed strong inhibition (>50%) of all macrofungi extracts against S. aureus. Hexagonia hydnoides exhibited the highest inhibition against both S. aureus (84.3%) and E. coli (14.1%). Chlorophyllum hortense, Lentinus concavus, Daedalea sp., and Panaeolus sp. demonstrated 83.7%, 82.4%, 81.25%, and 80% inhibition of S. aureus biofilm formation, respectively. However, the inhibition observed with all extracts against E. coli was not statistically significant (all <15%). The significant findings, particularly in inhibiting S. aureus biofilm production, indicate the presence of biological activity in the tested macrofungal extracts. These findings suggest their potential usefulness in the search for antibiofilm treatments