Role of anionic phospholipids in the adaptation of Bacillus subtilis to high salinity

• DOI: 10.1099/mic.0.28345-0
• Publication Date: 2006-03-02T23:59:32Z
• Authors: Claudia S. López; Alejandro F. Alice; Horacio Heras; Emilio A. Rivas; Carmen Sánchez-Rivas
• Keywords: Wild type; Strain (injury); Phosphatidylglycerol

The importance of the content anionic phospholipids [cardiolipin (CL) and phosphatidylglycerol (PG)] in osmotic adaptation membrane structure Bacillus subtilis cultures was investigated. Insertion mutations three putative cardiolipin synthase genes ( ywiE , ywnE ywjE ) were obtained. Only mutation resulted a complete deficiency thus corresponds to true clsA gene. osmotolerance mutant impaired: although at NaCl concentrations lower than 1·2 M growth curves similar those its wild-type control, 1·5 (LBN medium) lag period increased maximal optical density reached lower. strain showed an PG content, both exponential stationary phase, but no trace CL either LB or LBN medium. As well as synthesis, cls A other differences lipid fatty acids compared wild-type, suggesting cross-regulation pathways, crucial for maintenance functionality integrity. biophysical characteristics membranes large unilamellar vesicles from strains studied by Laurdan's steady-state fluorescence spectroscopy. At physiological temperature, decreased lateral packing protein-free isolated with strain. Interestingly, when they grown LBN. In conditional IPTG-controlled pgsA mutant, unable synthesize absence IPTG, osmoresistance correlated their phospholipids. transcriptional activity twofold upon entry phase under upshift. Overall, these results support involvement B. media containing elevated concentrations.