近年来，国内外学者对细菌生物膜形成机理进行了大量研究，但益生菌生物膜形成机理尚不清楚。该实验室前期以Lactobacillus plantarum GIM1.648（L. plantarum GIM1.648）为模型菌，探究了生物膜形成对L. plantarum GIM1.648抗逆性和抑菌性能的影响。但未涉及生物膜形成机理。对益生菌生物膜形成机理的了解将有助于今后通过分子手段促进生物膜的形成，进而提高益生菌的性能。因此，该文对L. plantarum GIM1.648生物膜的形成机理进行了研究。对差异基因进行GO功能富集分析，与浮游态相比，差异基因共注释到338个GO条目，且蛋白质和多糖的合成与代谢过程影响L. plantarum GIM1.648在静电纺纤维膜表面生物膜的形成；KEGG富集分析显示，差异基因共注释到56个代谢通路，主要集中于嘧啶代谢、双组分系统和色氨酸生物合成等通路，这会促进生物膜形成。此外，调控脂肪酸生物合成、肽聚糖合成和ABC转运的相关基因表达上调，利于菌体耐受不良环境。生物膜态细胞luxS基因表达量是浮游态细胞的8.7倍。该研究初步阐明了L. plantarum GIM1.648形成生物膜的机理，为后续利用生物膜提高益生菌在应用过程中的稳定性奠定了基础。

In recent years, the formation mechanism of bacterial biofilms has been frequently investigated by researchers locally and abroad, but the formation mechanism of probiotic biofilms remains unclear. In our laboratory, Lactobacillus plantarum GIM1.648 has been used as a model strain to explore the effects of biofilm formation on stress resistance and antibacterial properties. However, the mechanism of biofilm formation has not been elucidated. Understanding the mechanism of probiotic biofilm formation will aid in promoting the formation of biofilms through molecular methods in the future, thereby enhancing the efficacy of probiotics. Therefore, the formation mechanism of the L. plantarum GIM1.648 biofilm was investigated in this study. Gene Ontology (GO) function enrichment analysis showed that the differentially expressed genes between the biofilm and planktonic state were annotated to 338 GO entries. The synthesis and metabolism of proteins and polysaccharides were found to affect the biofilm formation of L. plantarum GIM1.648 on the surface of electrospun fiber membranes. Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis showed that the differentially expressed genes were annotated to 56 pathways; pyrimidine metabolism, the two-component system, and tryptophan biosynthesis of L. plantarum GIM1.648 were identified as key factors in promoting biofilm formation. In addition, the expression levels of genes related to the regulation of fatty acid biosynthesis, peptidoglycan synthesis, and ABC transport were upregulated, which beneficial for enhancing the tolerance of the bacteria to adverse environmental conditions. The luxS gene expression level of the biofilm cells was 8.7 times that of the planktonic cells. This study provides a preliminarily clarification of the formation mechanism of L. plantarum GIM1.648 biofilm, thus establishing a basis for utilizing biofilms to improve the stability of probiotics.

广东省重点领域研发计划项目（2022B0202050002）；广州市科技计划项目（202206010165）