Microbial Lipids

Analytical Scheme:

In general, sediments will be freeze-dried (in the case of carbonate crusts, dried and then ground) and then extracted. The extracts will then be separated into neutral, acid and phospholipid fractions which can then be analysed be either GC or LC-based techniques. In some cases, samples will be further degraded into more GC-amenable components (i.e. saponification of phospholipid fraction) or further fractionated (i.e. neutral fraction into apolar and polar sub-fractions) to facilitate further analyses.

Lipid extraction:

Two extraction techniques will be used, depending on the type and quantity of sample; a blight dyer extraction will be used when attempting to characterise intact phsopholipids, and a soxhlet extraction will be used for general screening for bacterial and archaeal biomarkers. Note: in all cases, at least 25 g dried sediment will be archived.



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