食物分离株细菌素RM1的特性及应用研究

Characterization and Application of Enterocin RM1 Produced by Food Isolates Enterococcus faecalis

乳酸菌产生的细菌素由于其作为天然防腐剂和化学防腐剂的天然替代品而受到越来越多的关注。对从食物分离株RM1产生的细菌素(Ent-RM1)的特性及应用进行了研究,结果表明:筛选的细菌素Ent-RM1具有较高的热稳定性和较宽的pH稳定性,对蛋白酶K敏感。用16%的三-三甲基十二烷基硫酸钠聚丙烯酰胺凝胶电泳分析,Ent-RM1的分子量约为4.0k^4.5kDa。硫酸铵沉淀法提取的Ent-RM1(44.7 IU/m L Nisin当量)对接种到牛乳中的单核细胞增生李斯特菌Scott A有杀菌作用,对蜡状芽孢杆菌ATCC 11778具有抑菌作用。在磷酸盐缓冲液与高压处理联合作用,EntRM1对大肠杆菌K12表现出协同灭活作用,表明Ent-RM1对控制食品工业中的细菌污染具有实际应用价值。

Bacteriocins produced by lactic acid bacteria have received increasing attention due to their potential use as natural preservatives and as natural substitute for chemical preservatives.A bacteriocin(Ent-RM1)from food isolate Enterococcus faceail was selected for its characteristics and application.The results showed that Ent-RM1 had the properties of thermal stability,sensitive to protease K and stable in a wide range of pH.According to the gel electrophoresis analysis of SDS-PAGE,the molecular weight of Ent-RM1 was estimated to be4.0 k^4.5 k Da.Ent-RM1(44.7 nisin equivalent IU/m L)extracted by ammonium sulfate precipitation method had bactericidal effect on Listeria monocytogenes Scott A and bacteriostatic effect on Bacillus cereus ATCC 11778 in sterile milk.Although Ent-RM1 had no activity against Gram-negative bacteria,it displayed synergistic inactivation of Escherichia coli K12 when combined with HPP in PBS,indicating EntRM1 had practical application to control bacterial contamination in the food industry.