农家大酱作为东北地区传统的发酵性食品,在其发酵过程中,乳酸菌是影响农家大酱香气、滋味、色泽等的重要微生物。所以传统的农家大酱中,乳酸菌资源较为丰富。该实验旨在从农家大酱中筛选出耐盐性优良的乳酸菌菌株,有助于缩短大酱的生产周期、提高食品安全性和稳定产品质量,为构建东北地区乳酸菌菌种资源库做出贡献。实验中从传统农家大酱中筛选出耐盐性优良的乳酸菌菌株5株,当Na Cl浓度增加到12%时,菌株SY4-2、DL3-1、DL4-5、FS1-11、FS5-5的OD600值在0.097~0.137之间。对菌株提取DNA,经PCR扩增后,测其16S r DNA序列,并与基因库中基因序列进行同源性比较,经鉴定2株为屎肠球菌,3株为植物乳杆菌。

Farmers' soybean paste is a traditional fermented food in the northeast. In the process of its fermentation,lactic acid bacteria are important microorganisms which affect the aroma,taste and color of farm peasant sauce.Therefore,lactic acid bacteria resource is rich in traditional farmers' soybean paste. This study was designed to filter out the superior salt resistance lactic acid bacteria to shorten soybean paste production cycle,improve food safety and stable product quality,and thus contribute to lactic acid bacteria resource repository in Northeast. In this experiment,5 strains of excellent salt resistance lactic acid bacteria were screened from farmers' soybean paste. When the concentration of Na Cl increased to 12%,the OD600 values of strain SY4-2,DL4-5,DL3-1,FS1-11,and FS5-5 were between 0. 097 ~ 0. 137. The DNA extracted from these strains were measured by 16 s r DNA sequencing after PCR amplification,and then compared with those of homologous gene sequences in gene Banks. Two strains were identified as the Excrement enterococcus and three strains were identified as Lactobacillus plantarum.