藏灵菇中嗜热链球菌高产胞外多糖发酵条件的优化

Optimization of exopolysaccharide production conditions fermented by Streptococcus thermophilus from Tibetan kefir

利用从藏灵菇中筛选的产胞外多糖(EPS)的嗜热链球菌(Streptococcus thermophilus)研究提高多糖产量的环境因素。针对影响胞外多糖合成的4个因素,采用4因素3水平L9(34)正交试验,确定了高产胞外多糖优化发酵条件,即发酵温度为32℃,发酵时间为16h,培养基起始pH值为6.5,接种量为3%。在此优化条件下,胞外多糖的产量是优化前的2.6倍。

In this paper, the Streptococcus thermophilus of exopolysaccharide （EPS） screened from Tibetan keftr grains was used to study environment factors on increasing exopolysaccharide yield. For four factors which affect synthesize of exopolysaccharide, the fermentation conditions of high yield exopolysaccharide were determined by the four factors and three levels orthogonal experiments L9 （3^4）. The optimal condition was as follows： fermentation temperature 32℃, fermentation time 16 h, culture medium origin pH value 6.5, amount of inoculation 3%. In the optimization conditions, the yield ofexopolysaccharide was 2.6 times before optimize.