摘要
Lactic acid bacteria(LAB)are often exposed to ionizing radiation(IR)in the process of mutagenesis and food processing,and high doses of IR can cause damage and death to LAB.LlrG,a response regulator(RR)in twocomponent system(TCS),holds a significant role in enabling LAB to adapt to the environment.In our previous study,the expression of LlrG protein in Lactococcus lactis subsp.lactis IL1403(L.lactis IL1403)was significantly increased after induction by IR.To explore the IR adaptation mechanism of L.lactis IL1403 regulated by LlrG,the gene llrG in L.lactis IL1403 was overexpressed(L.lactis IL1403-llrG)and the transcriptomics and proteomics were studied.Results showed that L.lactis IL1403-llrG had significantly higher survival rate and stronger antioxidant capacity under IR conditions compared with L.lactis IL1403-p(L.lactis IL1403 contained pMG36e).Meanwhile,the transcriptomics and proteomics analyses indicated that the overexpression of llrG resulted in the enhancement of oxidation-reduction process,response to stimulus and carbohydrate metabolism and the downregulation of amino acid biosynthesis.This research provided a new perspective on understanding the adaptive mechanism of L.lactis IL1403 response to IR based on LlrG.Furthermore,L.lactis strain with IRstress tolerance characteristic could act as a reference for the application in IR sterilization of probiotic fermented dairy products.
基金
supported by the Zhongyuan Sci-Tech Innovation Leading Talents(254000510040)
the National Natural Science Foun-dation of China(32172211)
the Key Science Research Projects of Higher Education Institutions in Henan Province(21A530006)
the Henan Provincial Natural Science Foundation General Program(252300421403)
the Key Research and Development and Promo-tion Projects of Henan Province(232102310293).
