植物乳杆菌XCT-1对温和气单胞菌群体感应及生物膜形成的抑制作用

Inhibitory Effects of Lactobacillus plantarum XCT-1 on Quorum Sensing and Biofilm Formation of Aeromonas sobria

利用双层琼脂扩散法从辽宁葫芦岛农家腌芥菜中获得对温和气单胞群体感应有较强抑制活性的菌株XCT-1,该菌株经生理生化和16S r RNA序列被鉴定为植物乳杆菌。4 mg/mL菌株XCT-1代谢产物的粗提物对温和气单胞菌生物膜的抑制率为38%,显微镜观察显示其粗提物能够减少细菌生物膜的形成。扫描电镜结果表明:菌株XCT-1粗提物不仅降低了温和气单胞菌生物膜的生成量,而且使其生物膜结构疏松。菌株XCT-1粗提物经100℃30 min后其抑制活性保持不变,而经胃蛋白酶、木瓜蛋白酶、中性蛋白酶、胰蛋白酶和碱性蛋白酶处理后活性完全丧失。初步确定菌株XCT-1粗提物中的群体感应抑制成分为蛋白类物质,具有热稳定性。研究表明菌株XCT-1粗提物中的蛋白类物质主要通过干扰温和气单胞群体感应系统抑制其生物膜的形成。

Strain XCT-1 with inhibitory activity toward quorum sensing of Aeromonas sobria was isolated from homemade pickled leaf mustard(Huludao,Liaoning)using double agar diffusion method,which was identified as Lactobacillus plantarum by physiology and biochemical test and 16 S rRNA sequence analysis.4 mg/mL crude extract from strain XCT-1 inhibited the biofilm formation of A.sobria and inhibitory rate reached 38%.Light microscopy further demonstrated that crude extract from strain XCT-1 decreased biofilm formation of A.sobria.The scanning electron microscope images revealed that crude extract from strain XCT-1 not only decreased the production of biofilm of A.sobria,but also loosed the structure of biofilm.The crude extract from strain XCT-1 remained inhibition activity after incubation at 100℃for30 min,however,its activity completely lost after treatment with pepsin,papain,neutral protease,trypsin and alcalase.Therefore,the inhibition ingredient of crude extract from strain XCT-1 was preliminarily determined as proteins with heatstable.Theses results demonstrated that the inhibitory effect proteins of crude extract from strain XCT-1 on the biofilm formation of A.sobria through interfering its quorum sensing system.