Appraisal of paleoclimate indices based on bacterial 3-hydroxy fatty acids in 20 Chinese alkaline lakes

Yi Yang, Canfa Wang, James Bendle, Zhongyuan Luo, Xinyue Dang, Jiantao Xue, Xing Xiang, Shucheng Xie

Research output: Contribution to journalArticlepeer-review

39 Downloads (Pure)

Abstract

Bacterial 3-hydroxy fatty acids (3-OH-FAs) show potential for terrestrial paleoclimate reconstruction; however, the possibility of using 3-OH-FAs as proxies in lacustrine environments remains to be investigated. We analysed the composition and distribution of 3-OH-FAs in surface sediments from 20 Chinese alkaline lakes and investigated the development of climate proxies based on 3-OH-FAs in these lacustrine environments. The results show that lake sediments contain higher relative abundances of anteiso 3-OH-FAs compared to soils. Analysis of the gene community composition from Lake Liangzi reveals that Gram-negative bacterial communities in that lake environment are distinct from marine sediments from the South China Sea but share many characteristics with soils from Mt. Yujia at the phylum level. At the class level, the Lake Liangzi samples yield distinctly higher proportions of Deltaproteobacteria (23%), Betaproteobacteria (13%), Gammaproteobacteria (14%), and Bacterioidia (10%). pH proxies based on 3-OH-FAs (Branching Ratio, Branched index, RIN and RIAN) yield weak linear relationships with lake water pH, while RAN13 (previously proposed as a sea surface temperature proxy) shows a linear relationship with mean annual air temperatures (MAAT; ranging from 5 °C to 17 °C). The soil temperature proxies RAN15 (previously applied to a stalagmite) and RAN17 do not appear to be suitable for temperature calibration in lacustrine environments. We propose a novel temperature proxy (RIN17, ratio of iso to normal C17 3-OH-FA) for lake environments. These field-based correlations demonstrate that the physiological response of Gram-negative bacterial cell membranes to external environmental changes are recorded in lake sediments on a large regional scale. This further highlights the potential use of bacterial 3-OH-FAs as proxies for paleoclimate reconstruction in both aquatic and terrestrial environments.

Original languageEnglish
Article number104277
Number of pages10
JournalOrganic Geochemistry
Volume160
Early online date12 Jul 2021
DOIs
Publication statusPublished - Oct 2021

Bibliographical note

Funding Information:
We thank the Editors Dr. John Volkman and Dr. George Wolff and two anonymous reviewers for their constructive comments, which greatly improved the quality of this manuscript. This work was supported by the National Natural Science Foundation of China (Grant Nos. 41830319 , 41821001 , 41807419 , 41807317 , U20A2094 , 91951208 , 41773135 ), the State Key R&D Project of Ministry of Science and Technology (Grant No. 2016YFA0601100 ), the 111 project (Program of Introducing Talents of Discipline to Universities; Grant No. BP0820004 ).

Publisher Copyright:
© 2021 Elsevier Ltd

Keywords

  • 3-Hydroxy fatty acids
  • Gram-negative bacteria
  • Mean annual air temperature
  • Paleoclimate
  • Temperature proxy
  • Terrestrial environments

ASJC Scopus subject areas

  • Geochemistry and Petrology

Fingerprint

Dive into the research topics of 'Appraisal of paleoclimate indices based on bacterial 3-hydroxy fatty acids in 20 Chinese alkaline lakes'. Together they form a unique fingerprint.

Cite this