一株乳酸杆菌ZL43的分离鉴定及抑菌机制初探

Preliminary study on the identification and antibacterial mechanism of a lacid acid bacteria ZL43

目的:对从泡菜中分离到有较强抑菌活性的乳酸菌ZL43进行鉴定,并对其抗菌谱和抑菌机制进行研究。方法:采用形态学、生理生化特征结合16S r DNA序列分析,对菌株ZL43进行鉴定;采用杯碟法测定ZL43的抗菌谱;通过ZL43对大肠杆菌细胞超微结构、细胞蛋白的合成等方面的研究,探讨ZL43的抑菌机制。结果:菌种鉴定结果表明,ZL43为短乳杆菌(Lactobacillus brevis);ZL43对革兰阳性细菌和革兰阴性细菌均具有较好的抑制作用。扫描电镜结果表明ZL43可以导致大肠杆菌细胞壁破裂或形成孔洞;SDS-PAGE分析表明ZL43能影响大肠杆菌蛋白质的表达与合成。结论:短乳杆菌ZL43具有广谱抑菌活性,可以使细菌的细胞壁破裂或形成孔洞,导致胞内一些物质泄漏,并影响细菌蛋白的合成,使细胞生长受到抑制,进而导致其死亡。

Objective： A lacid acid bacteria ZL43, had strong inhibitory activity, was screened from pickles. Methods： Strain ZL43 was identified according to morphological, physiological, biochemical properties, and 16S rDNA sequence homolog comparison. The antibacterial spectrum of strain ZL43 was studied by cup-plate method. The effects of strain ZL43 on cell ultrastructure, protein synthesis of Escherichia coli were evaluated. Results： The strain ZL43 was identified as Lactobacillus brevis. It exhibited strong inhibitory activity against the gram-positive bacteria, including Micrococcus luteus, Bacillus subtilis, Staphyloccocus aureus. A strong activity was also observed against the gram-negative bacteria such as Escherichia coli, Salmonella gullinarum, Pseudomonas aeruginosa. Under scanning electron microscope, it was observed that the cell wall of Escherichia coli was ruptured by fermentation supernatant form strain ZL43 and holes were formed. SDS-PAGE suggested that fermentation supernatant from strain ZL43 had effect on protein synthesis in Escherichia coli cells. Conclusion： Lactobacillus brevis ZL43 had wide antibacterial spectrum. It inhibited Escherichia coli by rupturing the cell wall, and effecting protein synthesis.