酱香大曲中高温放线菌的筛选及其产蛋白酶条件优化

该研究从酱香大曲中分离筛选出高产蛋白酶的高温放线菌，对菌株进行形态学观察、生理生化试验和分子生物学鉴定，并通过单因素试验和正交试验研究其产蛋白酶的最适条件。结果表明，分离筛选到一株高产蛋白酶菌株，经鉴定，该菌株为普通高温放线菌（Thermoactinomyces vulgaris）。该菌株产蛋白酶的最优条件为pH 6.5，发酵温度45℃，发酵时间5 d，在此条件下，蛋白酶活力最高，为214.99 U/g，这对酱香大曲中酱香风味物质形成的研究有一定的参考意义。

Screening of high-temperature actinomycetes in sauce-flavor Daqu and optimization of protease-producing conditions

The high-temperature actinomycetes with high protease yield was isolated and screened from sauce-flavor Daqu, identified by morphological observation, physiological and biochemical tests and molecular identification, and the optimum conditions for protease production were studied by single factor tests and orthogonal tests. The results showed that a proteinase-producing strain was isolated and screened, which was identified as Thermoactinomyces vulgaris. The optimal conditions for protease production by the strain were pH 6.5, fermentation temperature 45 ℃ and time 5 d, under the conditions, the protease production activity of the strain was the highest, which was 214.99 U/g, which had certain reference significance for the study on the formation of pickles flavor substances in sauce-flavor Daqu.