单增李斯特菌lmo0331基因缺失株的构建及对环境耐受性的影响

Construction and Environmental Tolerance of lmo0331 Gene Deletion Mutant Strain of Listeria monocytogenes

为了研究Lmo0331蛋白在单增李斯特菌环境适应性中发挥的作用,利用同源重组的技术构建LM90SB2△lmo0331基因缺失株,比较在不同温度、pH、渗透压下的生长特性和生物被膜形成能力与野毒株的差异。结果显示,在4℃环境下及含5g/L NaCl的BHI培养基中,LM90SB△lmo0331缺失株的生长速度显著高于LM90SB2野毒株(P<0.05);在pH9的碱性环境及含45mL/L乙醇的BHI培养基中,LM90SB2△lmo0331缺失株繁殖数量低于野毒株(P<0.05);其他条件下,LM90SB△lmo0331缺失株与野毒株的生长无显著差异;LM90SB2和LM90SB2△lmo0331在不同时间点生物被膜形成密度无显著差异。由此表明,Lmo0331蛋白可能在低温和碱性条件下发挥不同作用,这一结果为研究LM在胁迫环境生存机制奠定了基础。

To study the role of Lmo0331protein on environmental tolerance of Listeria monocytogenes(LM),based on homologous recombination technology,LM90SB2△lmo0331deletion mutant was constructed.The growth curves of LM90SB2and LM90SB2△lmo0331under different temperatures,pH,osmotic pressure and the ability of biofilm formation were detected.The growth of LM90SB2△lmo0331was better than that of LM90SB2at 4℃and 5g/L NaCl(P<0.05)BHI medium.The resistant ability of LM90SB2△lmo0331was significantly lower than that of LM90SB2in the alkali(pH9)and 45mL/L ethanol(P<0.05).The growth of LM90SB2△lmo0331and LM90SB2was not significantly different under other stress conditions.There was no significant different in biofilm formation ability between LM90SB2and LM90SB2△lmo0331at different time points.The results suggested that Lmo0331protein of Listeria monocytogenes plays different roles under low temperature and alkalinity stress conditions,which laid the foundation for study LM in environmental tolerance.