高糖和氮源对鼠李糖乳杆菌(Lactobacillus rhamnosus)L-乳酸发酵的影响  

Effects of high sugar concentration and nitrogen sources on L-lactic acid fermentation using Lactobacillus rhamnosus

作　　者：李海军[1] 林建群[1] 林建强[1] 曲音波[1] 董锡文[1] 

机构地区：[1]山东大学生命科学学院微生物技术国家重点实验室,济南250100

出　　处：《工业微生物》2006年第4期22-27,共6页Industrial Microbiology

摘　　要：鼠李糖乳杆菌经实验室耐高糖高酸选育,能够在高糖浓度下高效高产L-乳酸。以酵母粉为氮源和生长因子,葡萄糖初始浓度分别为120 g/L和146 g/L,摇瓶培养120h,L-乳酸产量分别为104g/L和117.5g/L,L-乳酸得率分别为86.7%和80.5%。高葡萄糖浓度对菌的生长和乳酸发酵有一定的抑制。增加接种量,在高糖浓度发酵条件下,可以缩短发酵时间,但对增加乳酸产量效果不明显。乳酸浓度对鼠李糖乳杆菌生长和产酸有显著的影响。初始乳酸浓度到达70g/L以上时,鼠李糖乳杆菌基本不生长和产酸,葡萄糖消耗也被抑制。酵母粉是鼠李糖乳杆菌的优良氮源,使用其它被测试的氮源菌体生长和产酸都有一定程度的下降。用廉价的黄豆粉并补充微量维生素液,替代培养基中的酵母粉,可以使产酸浓度和碳源得率得以基本维持。A homofermentative strain, Lactobacillus rhamnosus was domesticated to produce L-lactic acid with high efficiency and productivity under high sugar and lactic acid concentrations. After 120 h of fermentation in flasks, using yeast extract as the nitrogen source and growth factors, 120 g/L and 146 g/L of glucose were converted to L-lactic acid of 104 g/L, and 117.5 g/L, respectively. At high sugar concentration, the increasement of inoculation volume from 5 % to 15 %, reduced the fermentation period but the L-lactic acid production was not obviously increased. The initial lactic acid concentration over 30 g/L strongly inhibited the cell growth and L-lactic acid production. When initial lactic acid concentration was increased to 70 g/L, cell growth and L-lactic acid production were completely stopped. Yeast extract was the best nitrogen source, while the other tested nitrogen sources reduced the cell growth and lactic acid production. Cheap soybean flour supplemented with a mixture of vitamins could replace the relatively expensive yeast extract in culture medium for maintaining the level of L-lactic acid production.

关 键 词：L-乳酸 鼠李糖乳杆菌 发酵 

分 类 号：TQ922.9[轻工技术与工程—发酵工程]