淡水鱼肠道中抗芽孢杆菌性乳酸菌的筛选与鉴定

缪璐欢; 杜静芳; 马欢欢; 吕欣然; 李莹; 白凤翎; 仪淑敏; 励建荣

doi:10.13386/j.issn1002-0306.2015.16.030

淡水鱼肠道中抗芽孢杆菌性乳酸菌的筛选与鉴定

Screening and identification of lactic acid bacteria with antagonistic Bacillus spp. derived from freshwater fish intestine

摘要

摘要: 从淡水鱼肠道中筛选对芽孢杆菌具有较强拮抗活性的乳酸菌,结果表明:从鲤鱼肠道分离的菌株LY-19对蜡样芽孢杆菌和地衣芽孢杆菌的抑菌直径分别为16.89 mm和17.43 mm,活性主要来自无细胞上清液,在p H3.0⁴.5范围内保持抗菌活性,经中性蛋白酶、胃蛋白酶、木瓜蛋白酶处理后丧失部分抑菌活性,对α-淀粉酶不敏感,在40¹21℃范围内处理30 min后其拮抗活性基本不变,初步判定乳酸菌产生的抑菌物质为II型非糖基化类细菌素。根据生理生化特性和16S r DNA鉴定为清酒乳杆菌（Lactobacillus sakei）。

Abstract: Lactic acid bacteria(LAB) strains with strong antagonistic activity to Bacillus spp. were isolated from freshwater fish intestine in the study. The results showed that the diameters of inhibiting Bacillus cereus and Bacillus licheniformis by strain LY-19 from carp intestinal were 16.89 mm and 17.43 mm,respectively. The antagonistic activity was mainly from cell-free supernatants(CFS). The antibacterial activity of CFS kept within p H3.0~4.5,and lowered by treating with neutral protease,pepsin and papain,but was not sensitive to α-amylase.The antagonistic activity remained by thermal treatment from 40 ℃ to 121 ℃ for 30 min. The inhibitory substance of LAB produced was preliminary determined as type II non- glycosylation bacteriocin. Strain LY- 19 was identified as Lactobacillus sakei according to physiological and biochemical characteristics and 16 S r DNA sequence analysis.