利用双层平板法从浙东传统腌制冬瓜中筛选得到1株具有抑菌活性的乳酸菌,命名为L34.以大肠杆菌、金黄色葡萄球菌、枯草芽孢杆菌和蜡状芽孢杆菌为指示菌,利用牛津杯法测定乳酸菌发酵上清液的抑菌活性,发现其抑菌活性物质具有热稳定性,对部分蛋白酶敏感;抑菌活性随p H值的降低而增强,表现出对酸的依赖性.结合生理生化实验和16S r DNA序列比对结果,鉴定L34为植物乳杆菌.
One lactic acid bacteria with antibacterial activity was obtained from pickled wax gourd in Eastern Zhejiang by using the double-plate method, and named as L34. The antibacterial activity of lactic acid fermentation supernatant was measured by of oxford cup method, with the Escherichia coli, Staphylococcus aureus, Bacillus subtilis and Bacillus cereus as indicator bacteria. The results showed that antibacterial substances are thermally-stable, sensitive to some kinds of the proteases. The antibacterial activity increased with the decrease in p H. It showed a dependence of the acids. The strain was identified as Lactobacillus by 16 S r DNA molecular identification method.