De Angelis Maria, Siragusa Sonya, Campanella Daniela, Di Cagno Raffaella, Gobbetti Marco
Department of Soil, Plant and Food Science, University of Bari Aldo Moro, Bari, Italy.
Proteomics. 2015 Jul;15(13):2244-57. doi: 10.1002/pmic.201400363. Epub 2015 Apr 10.
This study investigated the relative abundance of extracellular and cell wall associated proteins (exoproteome), cytoplasmic proteins (proteome), and related phenotypic traits of Lactobacillus plantarum grown under planktonic and biofilm conditions. Lactobacillus plantarum DB200 was preliminarily selected due to its ability to form biofilms and to adhere to Caco2 cells. As shown by fluorescence microscope analysis, biofilm cells became longer and autoaggregated at higher levels than planktonic cells. The molar ratio between glucose consumed and lactate synthesised was markedly decreased under biofilm compared to planktonic conditions. DIGE analysis showed a differential exoproteome (115 protein spots) and proteome (44) between planktonic and biofilm L. plantarum DB200 cells. Proteins up- or downregulated by at least twofold (p < 0.05) were found to belong mainly to the following functional categories: cell wall and catabolic process, cell cycle and adhesion, transport, glycolysis and carbohydrate metabolism, exopolysaccharide metabolism, amino acid and protein metabolisms, fatty acid and lipid biosynthesis, purine and nucleotide metabolism, stress response, oxidation/reduction process, and energy metabolism. Many of the above proteins showed moonlighting behavior. In accordance with the high expression levels of stress proteins (e.g., DnaK, GroEL, ClpP, GroES, and catalase), biofilm cells demonstrated enhanced survival under conditions of environmental stress.
本研究调查了植物乳杆菌在浮游和生物膜条件下生长时细胞外和细胞壁相关蛋白（外蛋白质组）、细胞质蛋白（蛋白质组）的相对丰度以及相关表型特征。植物乳杆菌DB200因其形成生物膜和黏附于Caco2细胞的能力而被初步选定。荧光显微镜分析表明，与浮游细胞相比，生物膜细胞变得更长且自聚集水平更高。与浮游条件相比，生物膜条件下消耗的葡萄糖与合成的乳酸之间的摩尔比显著降低。差异凝胶电泳（DIGE）分析显示，浮游和生物膜状态的植物乳杆菌DB200细胞之间存在外蛋白质组差异（115个蛋白点）和蛋白质组差异（44个）。发现上调或下调至少两倍（p < 0.05）的蛋白质主要属于以下功能类别：细胞壁和分解代谢过程、细胞周期和黏附、转运、糖酵解和碳水化合物代谢、胞外多糖代谢、氨基酸和蛋白质代谢、脂肪酸和脂质生物合成、嘌呤和核苷酸代谢、应激反应、氧化/还原过程以及能量代谢。上述许多蛋白质表现出兼职行为。与应激蛋白（如DnaK、GroEL、ClpP、GroES和过氧化氢酶）的高表达水平一致，生物膜细胞在环境应激条件下表现出更强的存活能力。
