Bacillus lehensis G1 is an alkaliphilic bacterium that is capable of surviving in environments up to pH 11. Secretome related to bacterial acclimation in alkaline environment has been less studied compared to cytoplasmic and membrane proteome. The aim of this study was to gain better understanding of bacterial acclimation to alkaline media through analyzing extracellular proteins of B. lehensis. The pH range for B. lehensis growth was conducted, and two-dimensional electrophoresis and MALDI-TOF/TOF MS analysis were conducted to characterize changes in protein profiling in B. lehensis cultured at pH 8 and pH 11 when compared with those cultured at pH 10 (optimal growth pH). B. lehensis could grow well at pH ranging from 8 to 11 in which the bacteria showed to posses thinner flagella at pH 11. Proteomic analyses demonstrated that five proteins were up-regulated and 13 proteins were down-regulated at pH 8, whereas at pH 11, 14 proteins were up-regulated and 8 were down-regulated. Majority of the differentially expressed proteins were involved in the cell wall, main glycolytic pathways, the metabolism of amino acids and related molecules and some proteins of unknown function. A total of 40 differentially expressed protein spots corresponding to 33 proteins were identified; including GlcNAc-binding protein A, chitinase, endopeptidase lytE, flagellar hook-associated proteins and enolase. These proteins may play important roles in acclimation to alkaline media via reallocation of cell wall structure and changes to cell surface glycolytic enzymes, amino acid metabolism, flagellar hook-associated proteins and chaperones to sustain life under pH-stressed conditions.

lehensis B1细菌是一种嗜碱细菌，能够在高达pH 11的环境中生存。与细胞质和膜蛋白质组相比，在碱性环境中与细菌驯化相关的分泌蛋白的研究较少。本研究的目的是通过分析lehensis的细胞外蛋白来更好地了解细菌对碱性介质的适应。进行了B. lehensis生长的pH范围分析，并进行了二维电泳和MALDI-TOF / TOF MS分析，以表征在pH 8和pH 11下培养的B. lehensis中蛋白质谱的变化。10（最佳生长pH）。莱氏芽孢杆菌可以在8至11的pH值下生长良好，其中细菌在pH 11时显示出较薄的鞭毛。蛋白质组学分析表明，在pH 8时，五个蛋白被上调，而在pH 11、14时被下调13个蛋白。蛋白质被上调，而8个被下调。大多数差异表达的蛋白质参与细胞壁，主要糖酵解途径，氨基酸和相关分子的代谢以及一些功能未知的蛋白质。总共鉴定出40个差异表达的蛋白质斑点，对应于33种蛋白质；包括GlcNAc结合蛋白A，几丁质酶，内肽酶lytE，鞭毛钩相关蛋白和烯醇化酶。