副溶血性弧菌拮抗菌的筛选及其拮抗条件

Screening and Antagonistic Conditions of Antagonistic Bacteria Against Vibrio parahaemolyticus

对分别分离自菜园土壤、大蒜植株、大豆植株、蔓花生植株、淡水湖淤泥、仙人掌植株、芹菜植株、细菌型豆豉和日本纳豆的可产抗大肠杆菌活性物质的42株细菌进行筛选,获得1株对副溶血性弧菌具有较强拮抗作用的菌株JNT02,其发酵液对副溶血性弧菌的抑菌圈直径为(20.87±0.83)mm;经16SrDNA序列分析和系统发育分析,菌株JNT02与枯草芽孢杆菌位于同一簇群,同源性达100%,初步鉴定为枯草芽孢杆菌;枯草芽孢杆菌JNT02在改良兰迪培养基中24h可完全杀灭共培养的副溶血性弧菌,并且种子液带入的抗菌物质对其拮抗作用有累积效应,在氯化钠碱性蛋白胨水培养基中枯草芽孢杆菌JNT02对副溶血性弧菌却只有一定抑制作用,在人工海水中没有拮抗作用;改良兰迪培养基有利于枯草芽孢杆菌JNT02产抗菌物质。结果表明,枯草芽孢杆菌JNT02对副溶血性弧菌的拮抗作用主要依赖于其代谢产生的抗菌活性物质,取决于环境条件是否有利于其产生抗菌活性物质,而并非是否有利于其生长。

The strain JNT02, which showed significantly inhibitory effects on the growth of Vibrio parah- aernolyticus with （20.87＋0.83） mm diameter of antibiotic circle fermented broth for antimicrobial activity assay, was screened from 42 bacterial strains isolated from vegetable garden soils, garlic plants, soybean plants, vine peanut plants, freshwater lake silts, cactus plants, celery plants, bacterial soybean lobster sauce and Japanese natto especially producing antibiotic substances against Escherichia coll. The strain JNT02 was classified into Bacillus subtilis base on 16S rDNA sequence and phylogenic analysis. In the im- proved Landy media, B. subtilis JNT02 completely killed the co-cultured V. parahaemolyticus in 24 h, and the enhancement of antagonistic effects of the antimicrobial substances brought from the B. subtilis JNT02 seed broth were also demonstrated. However, B. subtilis JNT02 showed weak inhibitory effects a- gainst the growth of V. parahaemolyticus in alkaline-peptone-water media and no antagonistic effects in artificial seawater. The improved Landy media were propitious to the antimicrobial substance production of B. subtilis JNT02. The findings indicated that the antagonistic action of B. subtilis JNT02 against V. parahaemolyticus was via the antimicrobial substance producing, and depended on the conditions of the an- timicrobial substance production, in stead of the growth of B. subtilis JNT02.