Isolation and identification of lactic acid bacteria from fermented vegetables and analysis for use as probiotics

• Main Authors: Chi-Lin Tsai, 蔡吉齡
• Other Authors: Tsong-Rong Yan
• Format: Others
• Language: zh-TW
• Published: 2002
• Online Access: http://ndltd.ncl.edu.tw/handle/10275930483187551698

碩士 === 大同大學 === 生物工程研究所 === 90 === Most lactic acid bacteria (LAB) are generally recognized as safe (GRAS) for human consumption, and used world wide in fermented dairy. LAB are widely distribution among animals and plants. Some of them are also considered as probiotics. LAB isolated form traditional fermented vegetables are different from that of cheese, yogurt, and fermented meat. Because LAB have large economic benefits in the industrial of fermented food products and milk products, it is important to screen LAB which have probiotics properties or specific functions. The purpose of this study was to survey the lactic acid bacteria flora of some Taiwanase local fermented vegetables and tried to find some LAB as usable probiotics. Total LAB counts of seven randomly sampled fermented vegetables were analyzed. The average of total LAB counts in five brands of chinese pickled vegetables were over 107 CFU/mL, however one brand of acidified vegetables and acidified bamboo shoot were less than that of pickled vegetables. Among the isolated LAB flora, 288 colonies with high acid producing ability were selected for further analysis. Through biochemical and microbial tests, 147 of 288 colonies were identified as Lactobacillus casei, 6 of 288 colonies were identified as Lactobacillus fermentum, 37 of 288 colonies were identified as Lactobacillus acidophilus, 94 of 288 colonies were identified as Lactococcus plantarum, and 4 of 288 colonies were identified as Lactococcus lactis. Through acid tolerance (pH 2.0, pH 3.0) and bile salts tolerance (0.2%、0.3%、0.4% bile salts) assays, 33 of 288 colonies were selected as high acid and bile salt tolerants. Analysis of the 33 colonies with simulated digestive tract analysis, adhere to Caco-2 cell, antimicrobial activity assay, and oligosaccharides digestiable assay, 6 colonies of Lactococcus plantarum strain E38, E46, E51 and Lactobacillus casei strain E7, E15,V38 were found to be could tolerant from digestive system, could adhere to Caco-2 cell, could restrain pathogen bacteria growth,and could digest isomaltooligosaccharides and gentiooligosaccharides.