具抑菌活性的乳酸菌的筛选

Screening of lactic acid bacteria with antibacterial activity

采用筛选培养基从泡菜中筛选乳酸菌株,并对其进行生化鉴定.以大肠杆菌、金黄色葡萄球菌、沙门氏菌为指示菌,采用抑菌圈法测定所筛菌株的抑菌活性.生化鉴定结果显示,筛选的3株乳酸菌分别为嗜热链球菌、植物乳杆菌及鼠李唐乳杆菌,但仅植物乳杆菌对金黄色葡萄球菌有抑菌作用,抑菌效果为发酵液>上清液>菌悬液.成功获得了1株对金黄色葡萄球菌有抑菌作用的植物乳杆菌,该植物乳杆菌中起抑菌作用的主要是发酵液中的胞外代谢产物.

The lactic acid bacteria was screened by using selective media from the kimchi and identifiying their species by commercial kits. The antibacterial activity of the screened lactic acid bacteria was deter- mined with inhibition zone method by using E. coli, Staphylococcus aureus and Salmonella as indicator bacteria. The biochemical identification shows that the three lactic acid bacteria screened from the kimchi were Lactobacillus plantaru,Streptococins thermopilos,and Lactobacillus rhamnosus GG. Only Lactoba- cillus plantaru has antibacterial effect on Staphylococcus aureus. The fermentation broth of the Lactoba- cillus plantarum has the best bacteriostatic effect on Staphylococcus aureus, and the bacterial supernatant of the Lactobacillus plantarum has better bacteriostatic effect than that of the suspension. A Lactobacil- lus plantarum strain with antibacterial activity was successfully screened,and the extracellular metabo- lites of Lactobacillus plantarum possess a major inhibitorv effect