http://dspace.cas.upm.edu.ph:8080/xmlui/handle/123456789/170 Bachelor thesis of BS Biology students 2026-05-12T07:31:56Z http://dspace.cas.upm.edu.ph:8080/xmlui/handle/123456789/3691 Cloning and Transformation of Salmonella typhi Flagellin Gene in the Yeast Expression Vector pPICZaA Ramos, Krzcht Odessa D.M.; Reyes, Elwilynne Q.T. Increased resistance to antibiotics and inefficient vaccines prompted the development of new vaccines against the typhoid bacterium Salmonella typhi. The object of the study was to clone and transform the antigenic hypervariable regions IV to VI of the S. typhi flagellin gene in the yeast expression vector pPICZaA, which will facilitate the production of stable recombinant yeast cells for the formulation of new vaccines. Plasmid pGTE-PCRII p23 containing the flagellin gene fragment and pPICZaA were isolated from Escherichia coli strain JM-109 and then subjected to restriction enzyme analysis using EcoRI/Xbal. The identified flagellin gene fragment was ligated to the yeast expression vector pPICZaA and the new construct was transformed into the E. coli strain DH5a. The transformants were selected based on their resistance to the antibiotic ZeocinTM and analyzed by restriction enzyme digestion with BgnI, EcoRI/Xbal, and HindIII/EcoRI. The new constructs, designated as pEO, were confirmed to be of the expected size - approximately equal to 4.1 kb. The pEO plasmids were isolated and transformed into the Pichia pastoris strain X-33 through electroporation (5 milliseconds at 1.5 kV) and the lithium chloride method. However, transformation in P. pastoris was unsuccessful. This may be due to one or several factors, such as technical and procedural errors. 2005-04-01T00:00:00Z http://dspace.cas.upm.edu.ph:8080/xmlui/handle/123456789/3680 A Taxonomic Survey of a Seagrass Community in the Northern Coast of Semirara Island, Antique Cedo, Joseph Paulo M. The dwindling stature of the ecosystem of today has drawn attention to its neglected aspects. It is only now that people are learning the importance of the seagrass community. The coexistence of Organisms in the estuarine regions has laid a bigger importance on seagrasses, thus, prompting this research. Using three transect lines of 100 meters in length each; a taxonomic survey of the seagrass community in the Northern Coast of Semirara Island, Antique was done. The results of the study show that after having computed for the Shannon's Diversity Index, the index was highest for seagrass (0.6393) while lowest for alga (0.3003). In Site C, the index was lowest for seagrass (0.2788), while highest for alga (0.4369). Likewise, it can be noted that the following species of seagrasses can be found in the sites: Enhalus acoroides, Cymodocea rotunda/a, Cymodocea sp., Halodule pinifolia, Halodule sp., and Halophila ovalis. Meanwhile, the following species of algae were found: Halimeda macroloba, Halimeda sp., Valonia sp., Galaxaura sp., and Dictyota sp. The seagrass community can be characterized by the dominant species, which is the Cymodecea rotundata. 1999-03-01T00:00:00Z http://dspace.cas.upm.edu.ph:8080/xmlui/handle/123456789/3676 Schistosoma Mansoni and S. Japonicum Cross-Reactive Antigens: Potential Candidate Molecules for a Universal Vaccine Abacan, Mary Ann R.; Receno, Pia Angela O. A universal vaccine which protects against both Schistosoma ma11s011i and japonicum infections is not available although it is highly desirable. This study addresses the need to identify cross-reactive antigens between the two schistosome species. This is the first step towards identification of cross reactive antigens which may potentially contribute to a universal schistosome vaccine in the future. In this study, the cross reactivity of S. mansoni antigens with S. japonicum infection sera were tested using the enzyme linked immunosorbent assay. Four S. manosni antigens, namely PB 1, PB2, P28 and P30 were tested with S. japonicum mouse, rabbit and human infection sera. Based on the graph and the statistical analysis using a student t-test, PB2 and P30 elicited a positive cross reaction. Between the two, PB2 exhibited greater cross reactivity. This data suggests that the S. mansoni antigens PB2 and P30 may be potential universal vaccine candidates. Future work should focus on determining whether S. mansoni antigen PB2 and P30 can protect mice against challenge infection with S. japonicum cercariae. 2000-04-01T00:00:00Z http://dspace.cas.upm.edu.ph:8080/xmlui/handle/123456789/3591 Partial Purification and Characterization of Phenoloxidase in Coconut Beetle Larvae (Oryctes rhinoceros L.) Umali, Janice; Yao, Jocelyn Coconut beetle larvae have a protein called phenoloxidase present in their hemolymph that is essential in arthropod immune response. Prior to characterization and isolation of an enzyme designing optimum assay conditions is crucial. This will stabilize the enzyme and ensure optimal activity. In this study, phenoloxidase activity was measured as a function of varying substrates, activators with their incubation periods and incubation temperatures, and buffer pH. The substrate 4-methylcatechol appeared as the best substrate for the enzyme. Among the activators tested, trypsin efficiently activated phenoloxidase within 20-60 minutes incubation periods at 30°C in sodium phosphate buffer with pH ranging from 6.0 to 8.0. The hemolymph was partially purified for pro-phenoloxidase through DEAE and SP ion-exchange chromatography. Fractions positive for enzyme activity were loaded on SOS-PAGE. Partially purified prophenoloxidase shows a molecular weight of 85-92 kDa while its active form (phenoloxidase) has a molecular weight of 62-67 kDa. 2002-03-01T00:00:00Z