The production of diverse brGDGTs by an Acidobacterium providing a physiological basis for paleoclimate proxies

Chen，Yufei1,2; Zheng，Fengfeng1,2; Yang，Huan3; Yang，Wei1; Wu，Ruijie1; Liu，Xinyu1; Liang，Huayang1; Chen，Huahui1; Pei，Hongye3; Zhang，Chuanlun1,2,4; Pancost，Richard D.5; Zeng，Zhirui1,2

2022

10.1016/j.gca.2022.08.033

GEOCHIMICA ET COSMOCHIMICA ACTA   Impact Factor & Quartile

0016-7037

1872-9533

Microbial lipid biomarkers preserved in geological archives can be used to explore past climate changes. Branched glycerol dialkyl glycerol tetraethers (brGDGTs) are unique bacterial biomarkers that have been used as molecular tools for the quantitative determination of terrestrial temperatures and the pH of depositional environments over a range of geological timescales. However, the exact biological source organisms – especially of the entire suite of brGDGTs found in the environment – remains unclear; by extension, so do the mechanisms that govern these proxies. Here, we identified a brGDGT-producing strain Candidatus Solibacter usitatus Ellin6076, by identifying archaeal tetraether synthase homologs in bacterial genomes. This strain synthesizes diverse brGDGTs, including regular C-methylated and cyclic brGDGTs, and brGDGTs comprise up to 66 % of the major quantified lipids, far exceeding the proportions found in previous studies. The degree of C-methylation in cultured strain Ellin6076 is primarily determined by temperature, whereas cyclization appears to be influenced by multiple factors, such as temperature, pH and oxygen availability. Consequently, culture-derived paleoclimate indices are in agreement with the global soil-derived MBT’ (methylation index of C-methyl brGDGTs) proxy for temperature, albeit with a differed slope, but not the CBT (cyclization index of C-methyl brGDGTs) proxy for pH. Our findings provide insights from a physiological perspective into the underlying mechanism of brGDGT-based proxies.

Acidobacteria BrGDGTs Lipid biomarker Membrane adaption Paleoclimate proxies

SCI

English

NI Journal Papers

First ; Corresponding

National Natural Science Foundation of China["32170041","42073072","20200925154325002"] ; Science, Technology, and Innovation Commission of Shenzhen Municipality[K19313901] ; Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou)[ZDSYS201802081843490] ; [92051112]

Geochemistry & Geophysics

Geochemistry & Geophysics

WOS:000892848700006

PERGAMON-ELSEVIER SCIENCE LTD

GEOSCIENCES

2-s2.0-85139025887

Scopus

1.Department of Ocean Science and Engineering,Southern University of Science and Technology,Shenzhen,518055,China
2.Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou),Guangzhou,511458,China
3.State Key Laboratory of Biogeology and Environmental Geology,Hubei Key Laboratory of Critical Zone Evolution,School of Geography and Information Engineering,China University of Geosciences,Wuhan,430074,China
4.Shenzhen Key Laboratory of Marine Archaea Geo-Omics,Southern University of Science and Technology,Shenzhen,518055,China
5.Organic Geochemistry Unit,School of Chemistry,School of Earth Sciences,Cabot Institute for the Environment,University of Bristol,Bristol,Cantock's Close,BS8 1TS,United Kingdom

Chen，Yufei,Zheng，Fengfeng,Yang，Huan,et al. The production of diverse brGDGTs by an Acidobacterium providing a physiological basis for paleoclimate proxies[J]. GEOCHIMICA ET COSMOCHIMICA ACTA,2022,337.

Chen，Yufei.,Zheng，Fengfeng.,Yang，Huan.,Yang，Wei.,Wu，Ruijie.,...&Zeng，Zhirui.(2022).The production of diverse brGDGTs by an Acidobacterium providing a physiological basis for paleoclimate proxies.GEOCHIMICA ET COSMOCHIMICA ACTA,337.

Chen，Yufei,et al."The production of diverse brGDGTs by an Acidobacterium providing a physiological basis for paleoclimate proxies".GEOCHIMICA ET COSMOCHIMICA ACTA 337(2022).