Enhancing the antibacterial activity of Lactobacillus reuteri against Escherichia coli by random mutagenesis and delineating its mechanism  

作　　者：Enyun Ma Yingfeng An Guoyan Zhang Mei Zhao Muhammad Waheed Iqbal Hossain M.Zabed Xianghui Qi 

机构地区：[1]School of Food and Biological Engineering,Jiangsu University,301 Xuefu Road,Zhenjiang,212013,Jiangsu,China [2]College of Biosciences and Biotechnology,Shenyang Agricultural University,120 Dongling Road,Shenyang,110161,Liaoning,China

出　　处：《Food Bioscience》2023年第1期132-141,共10页食品生物科学（英文）

基　　金：supported by the National Natural Science Foundation of China(Grant No.31972042,32272284 and 32150410349);Foreign Expert Program,Ministry of Science&Technology,China(Grant No.QNJ20200214015,QN2022012005L and QN2022014006L);Innovation and Entrepreneurship Program of Jiangsu Province,China(Grant No.SSCBS20210929).

摘　　要：In this study,Limsolactobacillus reuteri was genetically modified through random mutagenesis with atmospheric and room temperature plasma(ARTP),and mutants were screened for their antibacterial activity against Escherichia coli using high-throughput screening(HTS),which finally provided a mutant strain named AR-148.The cell-free supernatant of AR-148(MCFS)exhibited 37%higher antibacterial activity on E.coli compared to the wild strain.Subsequently,the antibacterial effects of MCFS were studied at the cellular level,including membrane integrity,energy metabolism of key enzymes,DNA replication,and protein synthesis.The results revealed that MCFS exerted its antibacterial effects by disrupting cell membranes,affecting intracellular biomolecules(protein and DNA),and decreasing the contents of the intracellular enzymes(AKPase andβ-galactosidase).Further transcriptome analysis confirmed that MCFS had significant effects on the expression of genes in E.coli involved in energy metabolism,oxidative stress,cell wall and cell membrane integrity,and genetic information.In this way,the present study revealed the antibacterial mechanism of MCFS against a Gramnegative bacterium for the first time,providing an experimental insight into antibacterial activity,which might be useful for further development and application of MCFS in food industries.

关 键 词：ARTP mutagenesis Antibacterial activity Antibacterial mechanism Transcriptome analysis Cell-free supernatant 

分 类 号：TS201.3[轻工技术与工程—食品科学]