一株细菌型豆豉发酵菌种的筛选及鉴定

摘要

从临沂细菌型豆豉中筛选出一株适于豆豉生产的高产蛋白酶菌种,并对此菌种进行鉴定。结果表明：采用酪蛋白平板初筛,制曲复筛,根据曲样蛋白酶酶活以及游离态含量共选出5株优良菌株用于豆豉的制作,由成品豆豉的理化指标和感官评定认为D2号菌种发酵的豆豉风味好,滋味鲜美。结合生理生化和16SrDNA序列分析初步鉴定D2号菌种为枯草芽孢杆菌,该菌株来源于豆豉,属于安全菌种,具有研究开发价值。%A bacteria producing high protease and suiting for fermenting lobster sauce from bacteria lobster sauce of Lin Yi was screened and identified.The result showed that five high-yield strains of protease were screened by casein plate and re-screened by starter making.According to the enzyme activity and free nitrogen＇s content of startor of lobster sauce,five superior strains were used to ferment lobster sauce respectively.According to the sensory tests,physical and chemical indexes of five products,the Lobster Sauce fermented by D2 strain had a good flavor and the product was very delicious.Combining physiological characters and the sequence analysis of 16S ribosomal DNA,the strain D2 was preliminarily identified as Bacillus subtilis.The strain from lobster sauce was safe,therefore it was worth further studying and developing.