Effect of fermentation conditions on production and characteristic of exopolysaccharide from lactic acid bacteria

• Main Authors: Chia-Chu, Weng, 翁嘉鞠
• Other Authors: 張勝善
• Format: Others
• Language: zh-TW
• Published: 2007
• Online Access: http://ndltd.ncl.edu.tw/handle/18197778156862106364

碩士 === 國立中興大學 === 動物科學系所 === 95 === The production of exopolysaccharide by lactic acid bacteria is growth-associated in MRSL (MRS+2% lactose) medium. A higher exopolysaccharide production can be found in MYPL medium (9% skim milk + 0.35% yeast extract+ 0.35% peptone+ 5% lactose), compared to the MRSL medium. The highest exopolysaccharide production can be achieved by the end of stationary phase in both media. There is high-molecular-mass exopolysaccharide synthesis in MRSL medium after incubation for 8 to 12 hours. The level of sodium cholate in the medium decreases as the cell growth and exopolysaccharide production increase, suggesting that there is an exopolysaccharide binding effect to the sodium cholate. Deconjugation activity of lactic acid bacteria is maximum in the late exponential phase of growth. The cell survival rate of lactic acid bacteria under the stress of acid, bile or gastrointestinal tract is low in MYPL medium.