肠膜明串株菌Leuco 4的筛选、鉴定及产糖条件的优化

摘要

A bacterial strain Leuco-4 capable of expressing high yield of exopolysaccharide on M17-sucrose agar was isolated from pickles of Yunnan and was identified as Leuconostoc mesenteroides (CGMCC NO.6432). The optimized conditions for Leuco 4 to biosynthesize polysaccharides was found to be a combination of 10%(w/w) skimmed milk, sucrose concentration of 5%(w/v), inoculation ratio of 2%(v/w), fermentation temperature of 28 ℃, respectively. After cultivated aerobically at shaker of 180 r/min for 80 hours under the optimized conditions, the polysaccharide in the fermentation broth of L. mesenteroides Leuco-4 reached 11 g/L.%以M17蔗糖培养基为筛选模型，从云南泡菜中筛选得到一株高产多糖的菌株Leuco 4，经鉴定为肠膜明串珠菌（CGMCC NO.6432）。对该菌株进行产糖条件优化实验后发现：在脱脂乳浓度10%（质量分数）、蔗糖浓度5%（w/v）、接种量2%（v/w）、发酵温度28℃的条件下，180 r/min摇床培养80 h后发酵液中多糖含量可达到11 g/L以上。