1株乳酸菌所产类细菌素Lactobacillin SD-22的初步研究

自泡菜中分离的329株乳酸菌中筛选出1株具有较广抑菌活性的菌株SD-22,经鉴定为短乳杆菌(Lac- tobacillus brevis)。在排除酸性产物和过氧化氢的干扰后,SD-22菌株发酵液对金黄色葡萄球菌(Staphyloccocus aureus),枯草芽孢杆菌(Bacillus subtilis),蜡状芽孢杆菌(Bacillus cereus)等革兰氏阳性菌和大肠杆菌(Esche- richia coli),鼠伤寒沙门氏菌(Salmonella typhimuniuns)等革兰氏阴性菌具有较好的抑制作用,而且对部分真菌也有抑制作用;经胰蛋白酶、胃蛋白酶和蛋白酶K处理后发酵液抑菌活性略有下降,表明该活性物质为非蛋白成分或起抑菌作用的非单一物质。该活性物质不同于一般细菌素,属于类细菌素,命名为LactobacillinSD-22。它具有很好的热稳定性,在酸性条件下稳定且活性高,对蛋白酶敏感性低,且具有较广的抗菌谱。

Preliminary Studies on Bacteriocin-like Substance Synthesized by Lactobacillus

A strain,identified as Lactobacillus brevis,SD-22,having ability in producing inhibitory activity substance,was screened from 329 isolates of lactic acid bacteria from pickles.Without the effect of organic acids and hydrogen peroxide,supernatant of the liquid culture of SD-22 showed significant inhibitory activity against gram-positive bacteria,including Staphyloccocus aureus,Bacillus subtilis,Bacillus cereus and gram- negative bacteria such as Escherichia coli,Salmonella typhimuniuns.Inhibition of some kind of epiphyte was also found.After treatment with trypsin,pepsin and proteinase K,the culture's inhibitory activity de- creased slightly.The inhibitory substance,termed as Lactobacillin SD-22 showed good heating stability, high activity at low pH,low sensitivity to proteinases and a broad antibacterial spectrum.This indicated it belongs to a kind of bacteriocin-like substance.