柠檬酸高浓度发酵过程中糖化酶活性对柠檬酸发酵的影响  

Effects of the Aspergillus niger glucoamylase activity on citric acid high gravity fermentation

作　　者：赵祥颖[1] 乔君[1] 马钦元 刘建军[1] 田延军[1] 范宜晓[1] 赵晨[1] 

机构地区：[1]山东省食品发酵工程重点实验室,山东济南250013 [2]潍坊英轩实业有限公司,山东潍坊262400

出　　处：《食品与发酵工业》2015年第10期29-33,共5页Food and Fermentation Industries

基　　金：山东省泰山学者岗位建设工程经费资助(No.ts20130919);山东省自主创新专项(2012CX20505)

摘　　要：在进行柠檬酸高浓发酵的研究中发现,柠檬酸高浓发酵残糖高的主要原因是发酵料液中的糖化酶迅速失活、液化淀粉糖化不完全。对生产菌株分泌糖化酶的性质进行研究显示,该酶能够耐受较低pH值,在pH 2.0以下时仍能保留50%以上的酶活性,但对柠檬酸耐受性较差,20 g/L柠檬酸就会对酶活力造成强烈抑制,酶活力损失达90%以上。通过在发酵料液中预加商品糖化酶,加快糖化进程,及时完成糖化,解决了柠檬酸高浓度发酵残糖高的问题。A high residual total sugar concentration was discovered during the high gravity fermentation of citric acid, which was resulted from deactivation of glucoamylase activity of Aspergillus niger and thus incomplete saccharifi- cation of liquefied starch. The property of the glucoamylase secreted by A. niger YX-1217 was investigated and results showed that it could still keep above 50% of enzyme activity below pH 2.0. But, it had poor tolerance to citric acid, 20 g/L of citric acid would exert a strong inhibition on its enzyme activity and the damage would exceed 90%. In or- der to solve this problem, the commercial glucoamylase was added into the fermentation broth before the fermentation started. Based on the operation process, the saccharification process could be accelerated to a degree and it could be finished ahead of time, which would solve the problem of high residual total sugar in the citric acid high gravity fer- mentation.

关 键 词：黑曲霉 柠檬酸 高浓度发酵 糖化酶 残总糖 

分 类 号：TQ921.1[轻工技术与工程—发酵工程]