小肠结肠炎耶尔森氏菌是革兰氏阴性食源性致病菌，能够在食物以及食品加工设备表面形成生物膜。生物膜可以增强菌株的生存能力并危害食品安全。该文以分离自速冻食品且具有强生物膜形成能力的小肠结肠炎耶尔森氏菌C1967-1作为出发菌株。通过蛋白质组分析生物膜与浮游态细菌中的蛋白表达差异。GO富集分析表明富集程度最大的前9个GO条目中，7个条目在生物膜中呈现下调趋势。仅GO:0046873（金属离子跨膜转运蛋白活性）条目在生物膜中未呈现明显上下调趋势。KEGG富集结果表明富集程度最大的前20个KEGG通路主要涉及碳水化合物、氨基酸和脂质的代谢过程。亚细胞定位分析结果表明，45.65%的差异蛋白位于细胞质内。为进一步验证蛋白质组数据，从GO:0046873条目中筛选出生物膜上调蛋白MgtA并敲除基因mgtA。结果表明，mgtA的敲除没有抑制菌株的生长，但ΔmgtA的生物膜量下降约80%且生物膜结构松散。综上所述，研究结果为小肠结肠炎耶尔森氏菌生物膜形成机制以及其在食品行业生物膜防控提供重要理论依据。

Yersinia enterocolitica is a gram-negative foodborne pathogen that can form biofilms on the surfaces of food and food processing equipment. Biofilms can enhance strain viability and affect food safety. In this study, Y. enterocolitica strain C1967-1 isolated from quick-frozen food, which has a strong ability to form biofilms, was evaluated. Proteomics analysis was used to analyze the differences in protein expression between the biofilms and planktonic bacteria. Gene Ontology (GO) enrichment analysis demonstrated that, among the top nine GO categories with the highest degree of enrichment, seven showed downregulation trends in biofilms. Only GO:0046873 (metal ion transmembrane transporter activity) did not show significant upregulation or downregulation trends in biofilms. The Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment results suggested that the top 20 KEGG pathways with the highest degree of enrichment mainly involved metabolism of carbohydrates, amino acids, and lipids. The subcellular localization analysis results revealed that 45.65% of differential proteins were located in the cytoplasm. The upregulated protein MgtA of the biofilm was selected from GO:0046873, and the gene mgtA was knocked out to further verify the proteomics data. The results indicated that the knockout of mgtA did not inhibit strain growth. However, the biofilm amount of ΔmgtA was reduced by approximately 80%, and the structure of the biofilm was loosened. In summary, these results provide an important theoretical basis for the biofilm formation mechanism of Y. enterocolitica and the prevention of bacterial biofilm formation in the food industry.

广东省基础与应用基础研究重大项目（2020B0301030005）；广东特支计划项目（2021TQ06N119）；广东省重点实验室（2020B121201009）