甲基营养芽孢杆菌SK21.002产果聚糖蔗糖酶的发酵条件优化

Optimization of culture conditions for levansucrases by Bacillus methylotrophicus SK 21.002

摘要: 通过研究甲基营养芽孢杆菌SK21.002产果聚糖蔗糖酶的发酵条件,通过单因素实验和正交实验确定其最适产酶的发酵培养基为:蔗糖80g/L,酵母提取物10g/L,胰蛋白胨10g/L,K₂HPO₄ 8g/L,MgSO₄ 1g/L,NaCl 2g/L;最适产酶的发酵条件为:初始pH6.5,发酵温度30℃,装液量30%,接种量2%,发酵周期21h。在以上条件下发酵培养,果聚糖蔗糖酶活力可达到9.76U/mL,是优化前的3.75倍。

Abstract: The culture medium and culture conditions of Bacillus methylotrophicus SK 21.002 producing levansucrases were investigated.By single-factor experiment and orthogonal test, the optimal culture medium was determined as follows:sucrose 80g/L, yeast extract 10g/L, tryptone 10g/L, K₂HPO₄ 8g/L, MgSO₄ 1g/L, NaCl 2g/L, while the optimal culture conditions were initial pH6.5, fermentation temperature 30℃, medium volume 30%, inoculation ratio 2%, fermentation time 21h.Under these conditions, the yield of levansucrases reached 9.76U/mL, which was 3.75 times higher than it before optimization.