Date of Completion

2023

Document Type

Thesis

Degree Name

Bachelor of Science in Biochemistry

Keywords

Lactic Acid Bacteria (LAB), Lactobacillaceae, Pediococcus acidilactici, Genomic analysis

Abstract

Lactic acid bacteria (LAB) are a classification of microorganisms within the phylum Firmicutes. They are recognized for their capacity to ferment carbohydrates and produce lactic acid. LAB can be found in diverse natural habitats, such as plants, animals, and fermented food items. Extensive research has been conducted on LAB due to their significant contributions to food fermentation, probiotics, and human health. Pediococcus acidilactici, a Gram-positive bacterium falling under the family Lactobacillaceae, is a specific member of the LAB group. As a homofermentative LAB, Pediococcus acidilactici is known for its prominent lactic acid production during fermentation and its ability to withstand challenging conditions, including low pH levels and high salt concentrations. The objective of this study was to isolate Pediococcus acidilactici from traditional Filipino foods and examine if this has cholesterol-regulating capabilities, including longganisa, burong isda, burong hipon, and balao-balao. The isolated bacteria were primarily subjected to physiological characterization to confirm their identification as Pediococcus acidilactici. Tests such as catalase test, osmotic and temperature tolerance, MRVP test, citrate utilization test, starch hydrolysis, hydrogen sulfide production, and indole production were conducted, and the results exhibited similar characteristics to Pediococcus acidilactici. To further verify the identity of the isolated bacteria, genomic analysis and agarose gel electrophoresis was performed at the Philippine Genome Center (PGC). The analysis revealed a similarity percentage of 90.67% to 99.59% and a gel band size of 1500 base pairs(bp), confirming that the identity of the isolated bacteria was indeed Pediococcus acidilactici. The PGC also conducted agarose gel electrophoresis, which resulted in a band size of 1500bp, supporting the identification. Finally, the cholesterol regulation potential of Pediococcus acidilactici was assessed through UV-vis spectrophotometry. The analysis showed a significant decrease of 67.23% to 86.38% in cholesterol levels compared to the standard cholesterol, indicating the ability of Pediococcus acidilactici to lower cholesterol. The findings of this study underscore the potential of Pediococcus acidilactici as a promising candidate for further research and potential applications as a cholesterol regulator. In conclusion, this study demonstrated that Pediococcus acidilactici strains isolated from traditional Filipino fermented foods exhibited physiological characteristics, genomic identity, and cholesterol-regulating capabilities consistent with Pediococcus acidilactici. These findings contribute to our understanding of the potential applications of Pediococcus acidilactici in cholesterol regulation and pave the way for further research in this field.

First Advisor

Walter Aljohn T. Espiritu

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