发酵菌株HGPA20的蛋白酶活性及形态学研究

Research on the Protease Activity and Morphology of Fermented Strain HGPA20

传统的家庭自制豆酱是利用空气中的微生物自然发酵而成,这个过程酱醅表面附着了大量的真菌,某些功能菌株产生胞外蛋白分解大豆蛋白,使其变成人体能直接吸收利用的小肽。研究从东三省各地采集家庭自制豆酱,对豆酱上的真菌进行分离、培养及纯化。通过酪蛋白平板初筛获得具有蛋白酶活性的菌株35株。通过发酵复筛提取其粗酶液,用福林酚法测定蛋白酶活性,筛选出1株具有较高蛋白酶活性的曲霉菌HGPA20,经标准培养、形态学鉴定,确定该菌为米曲霉。

The traditional home-made soybean paste is fermented by microorganism in the air,and the fungi grow the most part of soybean mash surface.Some functional strains can produce extracellular protease to decompose soybean protein into small peptide for absorption and utilization of human body.The study collects the home-made soybean paste from different places in northeast of China, and isolate,cultivate and purify the fungi on the soybean paste.Use casein plating method to select 35 strains with protease activity.Through secondary screening of fermentation,the crude enzyme fluid has been extracted.One strain named HGPA20 with high protease activity has been screened out using Folin-phenol reagent method.Through standard cultivation and morphological identification,it confirms that this strain is Aspergillus oryzae .