Solvent tolerance is a novel trait among halotolerant bacteria and their enzymes. However, the solvent response mechanisms in Gram-positive bacteria remain less investigated. The Exiguobacterium indicum (TBG-PICH-001) was isolated from the sediment of Pichavaram estuary. It possessed halotolerance and could prove to be a suitable candidate for solvent tolerance studies. The present study extensively explores possible cellular mechanisms in a Gram-positive bacterium when exposed to the organic solvents. The isolate was highly tolerant towards hydrophobic solvents with high log P value such as tetradecane, dodecane, decane compared to the other hydrophobic solvents having low log P value, viz. octane, heptane, isooctane, and hexane. The electron micrographs showed less conspicuous differences in the bacterial cell membrane exposed to highly hydrophobic organic solvents. In contrast, anomalous cell aggregation and cell membrane disorganization was observed in the presence of comparatively less hydrophobic solvents. The spectroscopic assay for cell permeability and viability advocated the toxic effects of the solvents on the cells and their corresponding adaptability. Additionally, the microbe produced a high yield of alkaline protease (900 U/mL) in the presence of hydrophobic solvents. Such solvent stable proteases could find applications in solvent-mediated biosynthesis of peptides, while the solvent stable bacterial isolate might be an efficient biosystem for such bioprocesses. The significant level of cell tolerance could provide the response mechanism insights, while stable protease yield offers the cost-effective development of bioprocesses through non-aqueous enzymology and whole-cell bio-transformations.

耐溶剂性是耐盐细菌及其酶的新特性。然而，革兰氏阳性菌的溶剂反应机制研究较少。该微小杆菌野菊（TBG-PICH-001）得自Pichavaram河口沉积物分离。它具有耐盐性，可以证明是溶剂耐受性研究的合适候选者。本研究广泛探索了革兰氏阳性细菌暴露于有机溶剂时可能的细胞机制。与其他具有低 log P 值的疏水性溶剂相比，该分离物对具有高 log P值的疏水性溶剂（例如十四烷、十二烷、癸烷）具有高度耐受性价值，即。辛烷、庚烷、异辛烷和己烷。电子显微照片显示暴露于高度疏水性有机溶剂的细菌细胞膜差异不大。相比之下，在疏水性相对较低的溶剂存在下观察到异常的细胞聚集和细胞膜解体。细胞通透性和活力的光谱分析提倡溶剂对细胞的毒性作用及其相应的适应性。此外，该微生物在疏水性溶剂存在下可产生高产量的碱性蛋白酶 (900 U/mL)。这种溶剂稳定的蛋白酶可以在溶剂介导的肽生物合成中找到应用，而溶剂稳定的细菌分离物可能是此类生物过程的有效生物系统。