发酵豆制品中高产转氨酶菌株筛选及固态菌剂制备

为缩短传统大豆发酵制品后熟期，基于转氨反应这一主要风味形成途径，现从贵州各地采集风味良好的豆豉、腐乳等发酵样品，经稀释涂布平板法分离得到150株细菌。通过支链氨基酸转氨酶活力测定，从中筛选出WDH-8菌株具有最高酶活力，菌种鉴定后确定其为地衣芽孢杆菌，属安全益酵菌株，其支链氨基酸转氨酶活力达36.53U/mL。为便于生产应用，对该菌株进行固态菌剂培养基配方实验，以转氨酶活力为指标，培养基最佳配方为：黄豆粉25g、水料比1:1(V/m)、氯化钠添加量5%、葡萄糖添加量3%，其酶活力达到37.965U/mL。

Screening and Identification of Aminotransferase-producing Strain from Fermented Soybean Products and Preparation of Its Solid Starter Culture

In order to shorten the fermentation period of fermented soybean products,a total of 150 strains were isolated from top-quality fermented foods in Guizhou.Among these strains,strain WDH-8 was found to have the highest branched-chain aminotransferase activity.The strain was identified as Bacillus licheniformis that was a safe prebiotic yeast strain with a branched-chain aminotransferase activity of 36.53 U/mL.In order to facilitate practical applications,the preparation of its solid starter culture was investigated,and the optimal culture medium for achieving the highest branched-chain aminotransferase activity,37.965 U/mL,was determined to be composed of soybean power 25 g,material-to-water ratio 1:1,sodium chloride 5% and glucose 3%.