Reviews and syntheses: Heterotrophic fixation of inorganic carbon - significant but invisible flux in environmental carbon cycling.

Citation metadata

From: Biogeosciences(Vol. 18, Issue 12)
Publisher: Copernicus GmbH
Document Type: Brief article
Length: 225 words

Document controls

Main content

Abstract :

Heterotrophic CO.sub.2 fixation is a significant yet underappreciated CO.sub.2 flux in environmental carbon cycling. In contrast to photosynthesis and chemolithoautotrophy - the main recognized autotrophic CO.sub.2 fixation pathways - the importance of heterotrophic CO.sub.2 fixation remains enigmatic. All heterotrophs - from microorganisms to humans - take up CO.sub.2 and incorporate it into their biomass. Depending on the availability and quality of growth substrates, and drivers such as the CO.sub.2 partial pressure, heterotrophic CO.sub.2 fixation contributes at least 1 %-5 % and in the case of methanotrophs up to 50 % of the carbon biomass. Assuming a standing stock of global heterotrophic biomass of 47-85 Pg C, we roughly estimate that up to 5 Pg C might be derived from heterotrophic CO.sub.2 fixation, and up to 12 Pg C yr.sup.-1 originating from heterotrophic CO.sub.2 fixation is funneled into the global annual heterotrophic production of 34-245 Pg C yr.sup.-1 . These first estimates on the importance of heterotrophic fixation of inorganic carbon indicate that this pathway should be incorporated in present and future carbon cycling budgets.

Source Citation

Source Citation   

Gale Document Number: GALE|A665954091