重组抗冻肽在乳酸乳球菌中表达及其抗冻活性研究  

Expression of recombinant antifreeze peptide in Lactococcus lactis and its antifreeze activity

作　　者：张莉[1] 黄心阳 马添熠 吴金鸿[1] 汪少芸[1] 王正武[1] 

机构地区：[1]上海交通大学农业与生物学院,上海200240

出　　处：《食品与机械》2017年第10期123-127,144,共6页Food and Machinery

基　　金：国家自然科学基金项目(编号:31471623;21276154);国家重点研发计划项目(编号:2016YFD0400206)

摘　　要：为了优化抗冻蛋白SF-P的重组表达,利用乳酸链球菌素Nisin对已构建的重组乳酸乳球菌进行表达。通过对诱导时间、诱导pH、诱导温度和诱导剂Nisin浓度等诱导表达条件进行优化,利用SDS-PAGE和Western blot确定最佳的表达条件;通过比较冷冻胁迫前后菌体的生长状况、发酵活力和细胞内钠钾离子含量的变化,研究重组菌在冷冻胁迫作用下的生理功能特性。结果表明:优化后的最佳表达条件为pH 7.0,诱导剂Nisin浓度15ng/mL,温度25℃,诱导时间6h;SF-P2诱导重组菌株可以显著改善乳酸菌由于经受冷冻胁迫导致的对数生长延滞期和稳定生长延滞期的增加,表现出较强的酸化活力,并且可以有效降低冷冻胁迫过程对乳酸菌细胞膜通透性的影响,起到保护细胞生理功能的作用,表明SF-P2诱导重组菌具有显著的抗冷冻胁迫保护作用。In order to optimize the expression of antifreeze protein SF- P, using Nisin as the inducer to induced the expression of recombinant Lactococcus lactis. The expression conditions of induction time, induced pH, induced temperature and inducer Nisin concentration were optimized. The optimal expression conditions were determined by SDS-PAGE and Western blot. Furthermore, the physiological characteristics of recombinant bacteria under freezing stress were investigated by comparing the growth status, the acid production of bacteria and the changes of sodium and potassium contents before and after freezing stress. The results showed that the op- timal expression conditions were determined~ pH of 7.0, Nisin concentration of 15 ng/mL, temperature of 25℃, and incubation time of 6 h. The recombinant strain SF-P2 could significantly improved the growth of Lactococcus lactis in the logarithmic phase and the sta- ble growth lag following freezing, and bad a significant improvement in fermentation of L. lactis following freezing. It also could effectively reduced the effect of freezing stress on the permeability of cell membrane, which played a role in protecting the physiological function of cells. The results showed that the recombinant strain SF- P2 had significant protective effects against cold stress.

关 键 词：抗冻肽 乳酸乳球菌 重组表达 抗冻活性 冷冻胁迫 生理功能 

分 类 号：TS201.3[轻工技术与工程—食品科学]