Composite bacterial hopanoids and their microbial producers across oxygen gradients in the water column of the California current

Jenan J. Kharbush, Juan A. Ugalde, Shane L. Hogle, Eric E. Allen, Lihini I. Aluwihare

Research output: Contribution to journalArticlepeer-review

29 Citations (Scopus)

Abstract

Hopanoids are pentacyclic triterpenoid lipids produced by many prokaryotes as cell membrane components. The structural variations of composite hopanoids, or bacteriohopanepolyols (BHPs), produced by various bacterial genera make them potentially useful molecular biomarkers of bacterial communities and metabolic processes in both modern and ancient environments. Building on previous work suggesting that organisms in low-oxygen environments are important contributors to BHP production in the marine water column and that there may be physiological roles for BHPs specific to these environments, this study investigated the relationship between trends in BHP structural diversity and abundance and the genetic diversity of BHP producers for the first time in a low-oxygen environment of the Eastern Tropical North Pacific. Amplification of the hopanoid biosynthesis gene for squalene hopene cyclase (sqhC) indicated far greater genetic diversity than would be predicted by examining BHP structural diversity alone and that greater sqhC genetic diversity exists in the marine environment than is represented by cultured representatives and most marine metagenomes. In addition, the genetic relationships in this data set suggest microaerophilic environments as potential "hot spots" of BHP production. Finally, structural analysis of BHPs showed that an isomer of the commonly observed BHP bacteriohopanetetrol may be linked to a producer that is more abundant in low-oxygen environments. Results of this study increase the known diversity of BHP producers and provide a detailed phylogeny with implications for the role of hopanoids in modern bacteria, as well as the evolutionary history of hopanoid biosynthesis, both of which are important considerations for future interpretations of the marine sedimentary record.

Original languageEnglish
Pages (from-to)7491-7501
Number of pages11
JournalApplied and Environmental Microbiology
Volume79
Issue number23
DOIs
Publication statusPublished - Dec 2013
Externally publishedYes

ASJC Scopus subject areas

  • Biotechnology
  • Food Science
  • Applied Microbiology and Biotechnology
  • Ecology

Fingerprint

Dive into the research topics of 'Composite bacterial hopanoids and their microbial producers across oxygen gradients in the water column of the California current'. Together they form a unique fingerprint.

Cite this