Premium
Adjusting membrane lipids under salt stress: the case of the moderate halophilic organism H alobacillus halophilus
Author(s) -
Lopalco Patrizia,
Angelini Roberto,
Lobasso Simona,
Köcher Saskia,
Thompson Melanie,
Müller Volker,
Corcelli Angela
Publication year - 2013
Publication title -
environmental microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.954
H-Index - 188
eISSN - 1462-2920
pISSN - 1462-2912
DOI - 10.1111/j.1462-2920.2012.02870.x
Subject(s) - phosphatidylglycerol , phosphatidic acid , cardiolipin , phospholipid , halophile , chromatography , biology , biochemistry , phosphatidylcholine , membrane , biophysics , chemistry , bacteria , genetics
Summary The lipid composition of H alobacillus halophilus was investigated by combined thin‐layer chromatography and matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry analyses of the total lipid extract. Main polar lipids were found to be sulfoquinovosyldiacylglycerol and phosphatidylglycerol, while cardiolipin was a minor lipid together with phosphatidic acid, alanyl‐phosphatidylglycerol and two not yet fully identified lipid components. In addition the analyses of residual lipids, associated with denatured proteins after the lipid extraction, revealed the presence of significant amounts of cardiolipin, indicating that it is a not readily extractable phospholipid. Post decay source mass spectrometry analyses allowed the determination of acyl chains of main lipid components. On increasing the culture medium salinity, an increase in the shorter chains and the presence of chain unsaturations were observed. These changes in the lipid core structures might compensate for the increase in packing and rigidity of phospholipid and sulfoglycolipid polar heads in high‐salt medium, therefore contributing to the homeostasis of membrane fluidity and permeability in salt stress conditions.