Screening of lactic acid bacteria isolated from traditional fermented products: Potential probiotic bacteria with antimicrobial and cytotoxic activities
Date of Publication
2015
Document Type
Master's Thesis
Degree Name
Master of Science in Biology
Subject Categories
Biology
College
College of Science
Department/Unit
Biology
Thesis Adviser
Esperanza C. Cabrera
Defense Panel Chair
Delia C. Ontengco
Defense Panel Member
Chona Camille E. Vince Cruz
Patricio Elvin L. Cantiller
Abstract/Summary
Thirty (30) isolates of lactic acid bacteria (LAB) from traditionally-prepared fermented products specifically fermented soy-bean paste, fermented mustard and fermented rice-fish mixture were studied for their in vitro antimicrobial and cytotoxic activies. Seventeen (17) isolates were identified as Lactobacillus plantarum, while 13 isolates were identified as Enterococcus spp using 16s rDNA sequences. Disc diffusion method was used to determine the antibacterial activity of LAB against Staphylococcus aureus (ATCC 25923) and Escherichia coli (ATCC 25922), while the modified agar overlay method was used to determine the antifungal activity of LAB isolates on the yeast Candida albicans, and the dermatophytes Microsporum gypseum, Trichophyton rubrum and Epidermophyton floccosum. The filter-sterilized LAB supernatants were evaluated for their cytotoxicity to mammalian colon cancer cell lines (HT-29 and HCT116) and normal human dermal fibrolasts (HDFn) using resazurin assay (PrestoBlueTM) . Colchicine was the positive control. No antimicrobial activity was observed against the bacterial test organisms and the yeast Candida albicans. On the other hand, all of the tested LAB strains were fungicidal for all the test dermatophytes. Cytotoxicity index profiles of the supernatants of the 15 randomly picked LABs and negative control (brain heart infussion broth) suggest nontoxicity to the cells when compared to colchicine, whereas all LAB supernatants were found to be cytotoxic to HT- 29 and HCT116 colon cancer cell lines. Results provide strong support for the role of the lactic acid bacteria studied in antimicrobial treatment and anticancer therapy.
Abstract Format
html
Language
English
Format
Electronic
Accession Number
CDTG006531
Shelf Location
Archives, The Learning Commons, 12F Henry Sy Sr. Hall
Physical Description
1 computer optical disc ; 4 3/4 in.
Keywords
Lactic acid bacteria; Anti-infective agents; Probiotics
Recommended Citation
Agcaoili, G. T. (2015). Screening of lactic acid bacteria isolated from traditional fermented products: Potential probiotic bacteria with antimicrobial and cytotoxic activities. Retrieved from https://animorepository.dlsu.edu.ph/etd_masteral/5038