高温大曲中高产糖化酶菌株的筛选鉴定及固态发酵条件优化

对高温大曲中高产糖化酶菌株进行分离和鉴定,并对筛选得到的菌株进行发酵条件的优化。结果表明:试验前期获得的8株产酱香菌株中GX06菌株产糖化酶能力最强,同等条件下其糖化酶活力为706.13 U/g;通过形态观察及16S r DNA序列同源性分析,初步鉴定该菌株为Bacillus cereus;通过单因素和正交试验确定该菌株的最佳产酶条件为:以尿素为最佳氮源,以麸皮为最佳碳源,初始p H值6.0,接种量9%,在50℃下发酵70 h后,其产物糖化酶活性可达917.03 U/g。

Filtering and Identifying of High-yield Glucoamylase Strains from High Temperature Daqu and Optimization of Solid State Fermentation Conditions

Isolate and identify high-yield glucoamylase strains from high temperature Daqu and optimize the fermentation conditions of filtered strains. The results showed that, the 8 Jiangxiang-producing strains obtained from early stage of test, the GX06 strain has the strongest ability of producing glucoamylase, activity of glucoamylase is 706.13 U/g under the same conditions; by morphological observation and rDNA 16S sequence homology analysis, the strain was identiifed as Bacillus cereus; the best enzyme production conditions of the strain were determined by single factor and orthogonal test: using urea as the best nitrogen source, using wheat bran as the best carbon source, initial pH value of 6.0, inoculation amount of 9%, after 70 h fermentation under 50℃, the glucoamylase activity of its production is up to 917.03 U/g.