采用平板透明圈法初筛、摇瓶复筛,从半年鱼露发酵液中筛选到1株产蛋白酶乳酸菌T1。考察其生理生化性质、酶学特性,并加入鱼露发酵液中进行发酵试验。结果显示:经形态特征观察,初步鉴别T1乳酸菌为芽孢杆菌属(Bacillus sp.);其最适生长温度为32℃,pH为5.5;所产蛋白酶酶活最适温度为40℃,pH为7.0,最适条件下酶活力达72.2U/mL;添加T1乳酸菌发酵45 d,其TSN、AAN含量分别达到2.16 g/100 mL和0.89 g/100mL,接近国家一级鱼露标准,游离氨基酸总量为5 070.28 mg/100 mL,比同期自然发酵增加了1.05倍。

In order to find useful microorganisms that accelerate fish sauce fermentation,we used the method of transparent circle and shaking culture and isolated a proteinase producing Lactic acid bacteria T1 from 6-month-fermented fish sauce.We investigated the proteinase's physiological and biochemical properties,enzymatic properties and add it to fish sauce for fermentation test.The results showed: the optimum growth temperature of T1 was 32℃,pH was 5.5;the optimum temperature of proteinase was 40℃,pH was 7.0,the enzyme activity reached 72.2 U/mL;preliminary identified T1 was Bacillus sp.T1 played a positive contribution to the accelerated of fish sauce fermentation.After fermented for 45 days T1 was added to raw material of fish sauce,the contents of TSN and AAN were 2.16 g/100mL and 0.89g/100 mL which is close to the national standard of A grade fish sauce.The contents of free amino acid increased 1.05 times to 5 070.28 mg/100g.