摘要
为初步研究乳酸钠对单增李斯特菌生物被膜形成的抑制作用,作者首先采用结晶紫染色法检测不同质量浓度乳酸钠(0、2.5、5、10、20 g/dL)对单增李斯特菌生物被膜形成的抑制效果,其次探究乳酸钠对其生物被膜结构、胞外多糖和胞外蛋白、膜内细菌细胞活性及细胞膜完整性的影响,并采用荧光实时定量PCR(quantitative real-time PCR,qRT-PCR)检测其生物被膜相关基因motB、mogR、degU、flgE、dnaK、prfA及sigB的表达水平。结果表明,随着乳酸钠浓度的增高(2.5%～20%),其对单增李斯特菌生物被膜形成的抑制效果显著增强(p<0.05),抑制率分别为8.34%、32.2%、46.6%、55.2%。显微镜观察结果显示,经5 g/dL乳酸钠处理后,单增李斯特菌生物被膜结构明显变稀疏,厚度减少;同时胞外多糖和胞外蛋白质的形成量显著降低(p<0.05)。此外,该质量浓度下的乳酸钠可抑制膜内细菌细胞活性及破坏细胞膜的完整性,从而抑制新生物被膜的形成;实时定量PCR结果进一步显示,与单增李斯特菌生物被膜形成相关基因的表达显著下调(p<0.05)。本研究为乳酸钠可有效抑制单增李斯特菌生物被膜的形成提供科学依据。
The objective of this study was to investigate the inhibition effet of sodium lactate(NaL) on biofilm formation by Listeria monocytogenes. First of all,the crystal violet staining assay was used to evaluate the inhibition effect of NaL at different concentrations(0%,2.5%,5%,10% and 20%) on the biofilm formation of L. monocytogenes. Furthermore,the effets of NaL on its biofilm structure,polysaccharides,extracelluar proteins,cell activity and membrane integrity of L. monocytogenes biofilm cells were also investigated. Finally,the detection of the expression level of the biofilm-associated genes motB,mogR,degU,flgE,dnaK,prfA and sigB was performed by using quantitative real-time PCR(qRT-PCR). With the increase of the NaL concentration(2.5~20%),biofilm formation of L. monocytogenes was inhibited significantly(p<0.05) and the inhibition rate was 8.34 %,32.2 %,46.6 % and 55.2 %,respectively. Results of microscopy analysis showed that after 5 % NaL treatment,the structure of L. monocytogenes biofilm was forming instead of small clumps with reduction of thickness,and a significant decrease(p<0.05) was determined in total production of polysaccharides and extracelluar proteins of L. monocytogenes biofilm cells. In addition,5 % NaL inhibited the cell activity and membrane integrity of L. monocytogenes biofilm cells to suppress the development of new biofilms. qRT-PCR results revealed that NaL could downregulate biofilm-associated genes in L. monocytogenes and therefore to inhibit its biofilm formation. In conclusion,this study could provide a scientific basis for the effective inhibition of NaL on L. monocytogenes biofilm formation.
作者
付娇娇
王旭
刘海泉
孙晓红
谢晶
潘迎捷
赵勇
FU Jiaojiao;WANG Xu;LIU Haiquan;SUN Xiaohong;XIE Jing;PAN Yingjie;ZHAO Yong(College of Food Science and Technology,Shanghai Ocean University,Shanghai 201306,China;Shanghai Engineering Research Center of Aquatic-Product Processing & Preservation,Shanghai 201306,China;Laboratory of Quality & Safety Risk Assessment for Aquatic Product on Storage and Preservation(Shanghai),Ministry of Agriculture,Shanghai 201306,China)
出处
《食品与生物技术学报》
CAS
CSCD
北大核心
2019年第3期17-25,共9页
Journal of Food Science and Biotechnology
基金
国家自然科学基金项目(31271870
31571917)
国家"十二五"科技支撑计划项目(2015BAD17B01)
上海市科委计划项目(14DZ1205100
14320502100)
上海市科技兴农重点攻关项目(沪农科攻字2014第3-5号
2015第4-8号)
上海水产品加工及贮藏工程技术研究中心项目(11DZ2280300)
