产细菌素海洋乳酸菌的筛选及细菌素抑菌机制

Screening of Bacteriocin-producing Marine Lactic Acid Bacteria and Bacteriocin-inhibiting Mechanism

【目的】筛选海洋源产细菌素乳酸菌,探讨细菌素抑菌机制。【方法】从市售海鱼的肠道中筛选出一株对金黄色葡萄球菌(Staphylococcus aureus)和大肠埃希菌(Escherichia coli)有较强抑菌效果的菌株GOFEL226,通过16S rDNA序列鉴定乳酸菌,用乙酸乙酯提取细菌素,利用分光光度法、电导率法、扫描电镜技术探究细菌素的抑菌机制。【结果】菌株GOFEL226为戊糖乳植物杆菌(Lactiplantibacillus pentosus),GFEB226细菌素对金黄色葡萄球菌和大肠埃希菌的最小抑菌质量浓度为0.883 mg/mL;其对指示菌的生长有明显的抑制作用,可导致细胞的蛋白质、核苷酸、带电离子泄漏到细胞外,对细胞膜具有破坏作用。【结论】GFEB226细菌素可通过破坏革兰阳性和革兰阴性菌的细胞膜,使其胞内物质泄漏到胞外,进而导致细胞的死亡。

【Objective】The aim of this paper is to screen bacteriocin-producing lactic acid bacteria from marine fish,and analyze the bacteriostatic mechanism of the bacteriocin.【Method】A strain of GOFEL226,which has strong antibacterial effect on Staphylococcus aureus and Escherichia coli,was screened from the intestinal tract of Marine fish.The species of lactobacillus was identified by 16S rDNA sequence analysis.Bacteriocin was extracted by ethyl acetate,and the antibacterial mechanism of bacteriocin was investigated by spectrophotometry,conductivity method and scanning electron microscopy.【Result】The strain GOFEL226 was Lactiplantibacillus pentosus,and the minimum inhibitory concentration(MIC)of GFEB226 bacteriocin against S.aureus and E.coli was 0.883 mg/mL.GFEB226 bacteriocin obviously inhibited the growth of indicator bacteria,leading to the leakage of proteins,nucleotides and charged ions in the cell to the outside of the cell,and damaging the cell membrane.【Conclusion】GFEB226 bacteriotin can damage the cell membrane of Gram-positive and Gram-negative bacteria,causing the leakage of intracellular substances to the outside of the cell,thus can cause cell death.