Multiple environmental parameters impact core lipid cyclization in Sulfolobus acidocaldarius

Environmental reconstructions based on microbial lipids require understanding the coupling between environmental conditions and membrane physiology. The paleotemperature proxy TEX86 is built on the observation that archaea alter the number of five- and six-membered rings in the hydrophobic core of t...

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Bibliographic Details
Published inbioRxiv
Main Authors Cobban, Alec, Zhang, Yujiao, Zhou, Alice, Weber, Yuki, Pearson, Ann, Leavitt, William D
Format Paper
LanguageEnglish
Published Cold Spring Harbor Cold Spring Harbor Laboratory Press 24.04.2020
Subjects
Batch culture
Environmental changes
Environmental conditions
Glycerol
Growth rate
Hydrophobicity
Lipids
pH effects
Sulfolobus acidocaldarius
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Summary:Environmental reconstructions based on microbial lipids require understanding the coupling between environmental conditions and membrane physiology. The paleotemperature proxy TEX86 is built on the observation that archaea alter the number of five- and six-membered rings in the hydrophobic core of their glycerol dibiphytanyl glycerol tetraether (GDGT) membrane lipids when growing at different temperatures. However, recent work with these archaea also highlights a role for other factors, such as pH or energy availability in determining the degree of core lipid cyclization. To better understand the role of these variables we cultivated a model Crenarchaeon, Sulfolobus acidocaldarius, over a range in temperature, pH, oxygen flux, or agitation speed, and quantified the changes in growth rate, biomass yield, and core lipid compositions. The average degree of cyclization in core lipids correlated with growth rate under most conditions. When considered alongside other experimental findings from both the thermoacidophilic and mesoneutrophilic archaea, the results suggest the cyclization of archaeal lipids records a universal response to energy availability at the cellular level. Although we isolated the effects of individual parameters, there remains a need for multi-factor experiments (e.g., pH + temperature + redox) to establish a robust framework to interpret biomarker records of environmental change. Competing Interest Statement The authors have declared no competing interest. Footnotes * https://doi.org/10.6084/m9.figshare.c.4863426.v1 * https://git.dartmouth.edu/leavitt_lab/cobban-saci-lipids-batch-and-fed-batch-2020
DOI:10.1101/2020.04.23.032631