复合保鲜剂对腐生葡萄球菌的抑菌活性及其作用机理  

Antibacterial activity and mechanism of complex preservative on Staphylococcus saprophyticus

作　　者：朱亚珠[1] 林森森[1] ZHU Ya-zhu;LIN Sen-sen(Zhejiang International Maritime College, Zhoushan , Zhejiang 316021, China)

机构地区：[1]浙江国际海运职业技术学院,浙江舟山316021

出　　处：《食品与机械》2018年第4期158-162,共5页Food and Machinery

基　　金：浙江省自然科学基金面上项目(编号:LY15C200015);舟山市公益类科技项目(编号:2014C31052)

摘　　要：以山梨酸钾、双乙酸钠和异抗坏血酸钠作为复合保鲜剂的基本成分,研究其对虾皮中腐生葡萄球菌的抑菌作用。通过酶标法来确定复合保鲜剂对腐生葡萄球菌的最小抑菌浓度(MIC),测定抑菌活力、细菌生长曲线、细胞膜完整性、碱性磷酸酶(AKP)含量等指标,并结合细菌超微结构观察,综合评价复合保鲜剂对腐生葡萄球菌的作用效果。结果表明:复合保鲜剂能明显降低腐生葡萄球菌的生长速率,其最低抑菌浓度(MIC)为109μg/mL,最低杀菌浓度(MBC)为219μg/mL,抑菌活力均在使用初期的作用最强(约3h);随着作用时间的延长,菌液中的碱性磷酸酶量显著增多,在260nm处的吸收值显著增加,表明菌体内部核酸与蛋白质外泄,菌体细胞壁与细胞膜受到破坏。此外,电镜扫描结果显示,试验组的菌体发生干瘪破裂现象,细胞质从细胞内大量渗出。故一定浓度的复合保鲜剂对虾皮中的腐生葡萄球菌有抑制(杀灭)作用,对细胞体有一定破坏作用。The antibacterial effects of complex preservative of sorbate,sodium diacetate and sodium erythorbate on Staphylococcus saprophyticus in shrimps were investigated in this study.To determine the minimum inhibitory concentration of compound preservative on tested strain by ELISA method（MIC）,and determination of antimicrobial activity,bacterial growth curve,cell membrane integrity,alkaline phosphatase（AKP）levels and other indicators,combined with the observation of ultrastructure of bacteria,were used to evaluate the antibacterial influence of composite preservative on the S.saprophyticus.The results showed that the complex preservative can significantly reduce the growth rate of S.saprophyticus,its MIC is109μg/mL,the minimum bactericidal concentration（MBC）of219μg/mL,antimicrobial activity at the initial stage of use（around3 h）was the strongest.The amount of alkaline phosphatase in bacterial solution significantly increased with the prolongation of time,and the absorbance at 260 nm was significantly increased.It indicated that the bacterial DNA and protein leakage,cell wall and cell membrane was destroyed.Scanning electron microscopy showed that the dry rupture occurred for the experimental group,as well as rupture of cell wall and cytoplasm from the cell exudation.The compound preservative agent of certain concentration had inhibitory（killing）effect on S.saprophyticus in shrimps and showed certain destructive effect to the cell.

关 键 词：复合保鲜剂 腐生葡萄球菌 抑菌机理 

分 类 号：TS202.3[轻工技术与工程—食品科学]