Energetic Return on Investment Determines Overall Soil Microbial Activity

54 Pages Posted: 3 Jan 2022

See all articles by Louis J.P. Dufour

Louis J.P. Dufour

Swedish University of Agricultural Sciences (SLU)

Anke M. Herrmann

Swedish University of Agricultural Sciences (SLU)

Julie Leloup

affiliation not provided to SSRN

Cédric Przybylski

affiliation not provided to SSRN

Ludovic Foti

affiliation not provided to SSRN

Luc Abbadie

affiliation not provided to SSRN

Naoise Nunan

École Normale Supérieure (ENS)

Abstract

Microbial communities are a critical component of the soil carbon (C) cycle as they are responsible for the decomposition of both organic inputs from plants and of soil organic C. However, there is still no consensus about how to explicitly represent their role in terrestrial C cycling. The objective of the study was to determine how the energetic properties of organic matter affect the metabolic activity of the resident microbial communities in soils. This was achieved by cross-amending six soils with organic matter extracted from the same six soils and measuring heat dissipated due to the increase in microbial metabolic activity. The energetic properties of the organic matter were used to estimate a potential energetic return on investment that microbial communities could obtain from the transformation of the organic matter. Specifically, the energetic return on investment (ROI) was calculated as the ratio between the total net energy available (ΔE) and the weighted average standard state Gibbs energies of oxidation half reactions of organic C (ΔG°Cox). ΔE was measured as the heat of combustion using bomb calorimetry. ΔG°Cox was estimated using the average nominal oxidation state of C (NOSC) of the molecular species in the organic matter. We show that the potential energetic return on investment was positively related to the overall metabolic activity of microbial communities. However, the observed temporal differences in metabolism across soils indicate that bacterial communities do not exploit the potential energetic return on investment in the same ways. Overall, our results suggest that microbial communities preferentially use organic matter with a high potential energetic return on investment.

Keywords: Microbial Reaction Energetics, Community Composition, Ultra High Resolution Mass Spectrometry, Calorimetry, Organic Carbon

Suggested Citation

Dufour, Louis J.P. and Herrmann, Anke M. and Leloup, Julie and Przybylski, Cédric and Foti, Ludovic and Abbadie, Luc and Nunan, Naoise, Energetic Return on Investment Determines Overall Soil Microbial Activity. Available at SSRN: https://ssrn.com/abstract=3999054 or http://dx.doi.org/10.2139/ssrn.3999054

Louis J.P. Dufour (Contact Author)

Swedish University of Agricultural Sciences (SLU) ( email )

S-901 83 Umea
Sweden

Anke M. Herrmann

Swedish University of Agricultural Sciences (SLU) ( email )

S-901 83 Umea
Sweden

Julie Leloup

affiliation not provided to SSRN ( email )

No Address Available

Cédric Przybylski

affiliation not provided to SSRN ( email )

No Address Available

Ludovic Foti

affiliation not provided to SSRN ( email )

No Address Available

Luc Abbadie

affiliation not provided to SSRN ( email )

No Address Available

Naoise Nunan

École Normale Supérieure (ENS) ( email )

Do you have a job opening that you would like to promote on SSRN?

Paper statistics

Downloads
70
Abstract Views
204
Rank
519,130
PlumX Metrics