00000ctm a22000003a 4500 UP-8027390931313988696 Buklod 20170823162927.0 m |o d | ta 170823s2017 xx d r |||| u| (iLib)UPVIS-00048618233 Gift VML/nllb/08/23/2017 eng LG 995 2017 F5 H47 Herbalega, Precious Dee L. Screening and characterization of bacteriocin-producing lactic acid bacteria isolated from Balao-balao, a fermented rice-shrimp mixture byPrecious Dee L. Herbalega. Miagao, Iloilo University of the Philippines Visayas 2017. ix, 85 leaves. Thesis (M.S. Fisheries-Fish Processing Technology) -- Miagao, Iloilo : Institute of Fish Processing Technology, College of Fisheries and Ocean Sciences, University of the Philippines Visayas, June 2017. Lactic acid bacteria (LAB) from Philippine traditional fermented rice-shrimp mixture locally known s balao-balao was isolated and screened. From a total of 20 selected acid-producing isolates, four isolates (LM8, LM12, LM17, LM20) showed promising inhibitory activity against pathogens (S. aureus, E. coli, B subtilis and V. harveyi). Among the four isolates, LM12 showed the highest inhibitory activity. Optimum incubation period to achieve the highest activity was observed at 48 h. Isolate LM12 was identified as Pediococcus pentosacerus by phenotypical tests and 16s rDNA analysis. Complete inactivation on the activity of the cell free suoernatant was observed after treatment with trypsin and Preoteinase-K. The inhibitor activity was not affected by the addition of catalase and hydrogen peroxide thus the antimicrobial substance was proteinaceous in nature. Its molecular weight was approximately 5 kDa by Tris-Tricine SDS-PAGE. The bacteriocin of P. pentosaceus LM12 was sensitive to proteases but insensitive ti lipase and amylase. It was also pH (pH 2.0-11.0) and temperature stable (00C-1210C). After testing P. pentosaceus LM12 bacteriocin, results showed that it was active against both Gram-positive and Gram-negative bacteria. This is the first report of a bacteriocin-producing P. pentosaceus isolated from a fermented fish product with positive antagonism against Gram-positive and Gram-negative bacteria. Pediococcus pentasaceus. Lactic acid bacteria. Bacteriocin. Molecular weight. Litopenaeus vannamei. Simora, Rhoda Mae C., M.Sc. Chairman, Thesis Committee. UPVIS UPV-CFOS LG 995 2017 F5 H47 UPVIS UPV-GL LG 995 2017 F5 H47 Thesis