乳酸菌的筛选及高产酸菌株的常压室温等离子体诱变选育

Screening of lactic acid bacteria and breeding of high acid producing strain by ARTP mutation

为了筛选优质乳酸菌,建立乳酸菌的常压室温等离子体(atmospheric and room temperature plasma,ARTP)诱变方法,获得高蛋白酶活性的高产酸菌株。该研究从新疆4种传统酸奶中分离出12株疑似乳酸菌,经16S rRNA基因序列扩增和测序分析,确定分离株分属于乳植杆菌属(Lactiplantibacillus)和链球菌属(Streptococcus)的4个种。通过透明圈法和酶活力测定,筛选出5株产蛋白酶的乳酸菌,并对其中1株蛋白酶活性最高而产酸能力较弱的德氏乳植杆菌保加利亚亚种Y8菌株采用ARTP诱变技术进行了育种,获得1株蛋白酶活性稳定且高产酸的菌株Y8-6,为进一步开发相关优质乳酸菌资源及其在食品发酵工业中的应用奠定了基础。

In order to obtain high-quality lactic acid bacteria,the atmospheric and room temperature plasma(ARTP)mutagenesis method was used to screen high acid-producing isolates with high-protease activity.Twelve strains of lactic acid bacteria were isolated from four kinds of traditional yogurt in Xinjiang.Based on 16S rRNA gene sequences analysis,the isolates were identified as four species in genus Lactiplantibacillus and genus Streptococcus.Five protease-producing strains were screened out by clear circle method and enzyme activity measurement.Lactiplantibacillus delbrueckii subsp.Bulgaricus Y8 with the highest protease activity and weak acid production capacity was mutagenized by ARTP,after which a strain Y8-6 with stable protease activity and high acid production was obtained.These laid the foundation for the further development of related high-quality lactic acid bacteria resources and their application in the food fermentation industry.