Rapid extraction of lipid biomarkers from pure culture and environmental samples using pressurized accelerated hot solvent extraction

Lipid biomarker analysis is a quantitative and sensitive method for the in situ analysis of microbial communities in environmental samples (e.g. soil, water, air). The one-phase modified Bligh and Dyer solvent extraction is a commonly used method for obtaining phospholipid fatty acid biomarkers used in such community analysis. This method, however, is relatively labor intensive and slow, often taking up to 24 h for the initial extraction. Using a pressurized hot solvent extractor, we have been able to extract lipid biomarkers from selected vegetative and/or sporulated biomass ( Escherichia coli, Staphylococcus aureus, Mycobacterium fortuitum, Bacillus subtilis, Saccharomyces cerevisiae and Aspergillus niger) as well as from environmental samples collected from water, soil and air. Depending on sample type, the automated extraction procedure took ∼35–45 min per sample. Compared to the modified Bligh and Dyer extraction, phospholipid fatty acid lipid yields obtained using the pressurized hot solvent extraction were not significantly different for the vegetative biomass or water and soil samples ( P>0.05), but were significantly higher for the spores and the airborne biomass ( P