为了获得淡豆豉的发酵菌株,为淡豆豉的生产工艺标准化打下基础,首先结合形态及生理生化方法、16S rDNA序列比对和系统进化树构建对自然发酵淡豆豉中分解蛋白能力强的优势菌株进行鉴定,然后以这些优势菌株为发酵剂制作淡豆豉,测定淡豆豉的氨基酸态氮、三氯乙酸可溶性蛋白和肽分子量分布。结果表明:自然发酵淡豆豉中存在2种具有不同菌落形态的分解蛋白能力强的优势菌株,分别命名为DANDC1和DANDC2,它们都属于枯草芽孢杆菌。纯种发酵淡豆豉的氨基酸态氮、三氯乙酸可溶性蛋白和在5 000~2 000 u、2 000~1 000 u、1 000~500 u这3个分子量段的肽含量都显著高于蒸煮大豆,不同菌株发酵对淡豆豉的氨基酸态氮、三氯乙酸可溶性蛋白和肽分子量分布也都有显著影响。

To gain starter culture for laying the foundation for standardization of Dandouchi production technology,the predominant strains which had strong ability to decompose protein in naturally fermented Dandouchi were identified by morphological,physiological and biochemical methods,16S rDNA sequence alignment and phylogenetic tree construction firstly.Then amino acid nitrogen(AAN),trichloroacetic acid soluble protein(TCASP) and peptide molecular weight distribution(PMWD) of Dandouchi made by above strains were determined.Results showed that there were two kinds of predominant strains with different colonial morphology and strong ability to decompose protein in naturally fermented Dandouchi.They,named as DANDC1 and DANDC2,both belonged to Bacillus subtilis.The content of AAN,TCASP and peptides which molecular weight were 5 000～2 000 u,2 000～1 000 u and 1 000～500 u of Dandouchi made by starter culture were significantly higher than those of autoclaved soybean.Fermentation by different strains also significantly affected AAN and TCASP content and PMWD of Dandouchi.