四川泡菜中乳酸菌的抗菌性研究

Antimicrobial Properties of Lactic Acid Bacteria in Sichuan Pickles

乳酸菌在发酵食品中可以降低食品的pH值并产生天然抑菌代谢物,发掘天然抗菌物质已成为当下的研究热点。试验通过对52株从四川泡菜中分离得到的乳酸菌进行抑菌活性筛选,得到10株具有良好抑菌活性的乳酸菌菌株;采用牛津杯法对这10株乳酸菌的抗菌能力与代谢产物酸度之间的关系进行了研究,并比较了其代谢产物分别对细菌和产璞酵母的抑菌能力大小;对乳酸菌的抗菌机理进行了初步探讨。结果显示:对于同一种指示菌,乳酸菌的代谢产物总酸度越高,其抑菌能力越强;将代谢产物总酸中和至pH 7.0后,仅1株乳酸菌L7仍具有抗菌特性,其抗菌能力明显下降;同种乳酸菌对细菌的抗菌作用较强,对酵母菌几乎无抑制作用。经鉴定L7为植物乳杆菌,其代谢物对细菌和产璞酵母均有良好的抑制作用,在泡菜发酵中起重要作用。

The lactic acid bacteria applied in food has a long history,they can reduce pH value and pro-duce antibacterial material.10 strains of lactic acid bacteria with well antibacterial activity are screened out from 52 strains of lactic acid bacteria in pickled vegetable in Sichuan.Then the antibacte-rial properties of 10 strains of lactic acid bacteria and the relationship between the antibacterial activity of lactic acid bacteria and their metabolites are studied,and the antibacterial ability of lactic acid bacte-ria metabolites of bacteria and yeast are compared by agar-well diffusion method.At last,the antibac-terial mechanism of lactic acid bacteria is studied.The result shows that,for the same indicator bacte-ria,the stronger the antibacterial activity of lactic acid bacteria,the higher the total acidity.After the metabolites are naturalized to pH 7 .0 ,only L7 has antibacterial properties ,but the antibacterial ability is not obvious.The antibacterial activity of the same lactic acid bacteria to bacteria is obviously better than to yeast,and almost has no inhibition to yeast.L7 is identified as lactobacillus plantarum, its metabolites play an important role in inhibiting bacteria and yeast in pickles.