Vitamin B₁₂-dependent biosynthesis ties amplified 2-methylhopanoid production during oceanic anoxic events to nitrification.

ABSTRACT: Bacterial hopanoid lipids are ubiquitous in the geologic record and serve as biomarkers for reconstructing Earth's climatic and biogeochemical evolution. Specifically, the abundance of 2-methylhopanoids deposited during Mesozoic ocean anoxic events (OAEs) and other intervals has been interpreted to reflect proliferation of nitrogen-fixing marine cyanobacteria. However, there currently is no conclusive evidence for 2-methylhopanoid production by extant marine cyanobacteria. As an alternative explanation, here we report 2-methylhopanoid production by bacteria of the genus Nitrobacter, cosmopolitan nitrite oxidizers that inhabit nutrient-rich freshwater, brackish, and marine environments. The model organism Nitrobacter vulgaris produced only trace amounts of 2-methylhopanoids wh

SUBMITTER: Elling FJ 

PROVIDER: S-EPMC7777029 | biostudies-literature | 2020 Dec

REPOSITORIES: biostudies-literature