Microbial membrane lipids in active and inactive sinters from Champagne Pool, New Zealand: Elucidating past geothermal chemistry and microbiology

We examined the lipids preserved in active and inactive geothermal silica sinters (with ages of up to ca. 900 yr) from Champagne Pool, a hot spring in the Taupo Volcanic Zone, New Zealand. Amongst a range of lipid biomarkers, 1,2-di- O-alkylglycerols (diethers) and 1,2-di- O-phytanylglycerol (archaeol) are particularly abundant. Bacterial non-isoprenoidal diethers occur in highest abundance in young sinters, particularly when normalised relative to archaeol. In contrast, older sinters exhibit much lower abundance of the bacterial diethers relative to archaeol, suggesting a possible change in microbial assemblage in response to different environmental conditions.