Oxic-anoxic cycling promotes coupling between complex carbon metabolism and denitrification in woodchip bioreactors.

Autor: McGuire PM; School of Civil and Environmental Engineering, Cornell University, Ithaca, New York, USA., Butkevich N; School of Civil and Environmental Engineering, Cornell University, Ithaca, New York, USA., Saksena AV; School of Civil and Environmental Engineering, Cornell University, Ithaca, New York, USA., Walter MT; Department of Biological and Environmental Engineering, Cornell University, Ithaca, New York, USA., Shapleigh JP; Department of Microbiology, Cornell University, Ithaca, New York, USA., Reid MC; School of Civil and Environmental Engineering, Cornell University, Ithaca, New York, USA.
Jazyk: angličtina
Zdroj: Environmental microbiology [Environ Microbiol] 2023 Sep; Vol. 25 (9), pp. 1696-1712. Date of Electronic Publication: 2023 Apr 27.
DOI: 10.1111/1462-2920.16387
Abstrakt: Denitrifying woodchip bioreactors (WBRs) are increasingly used to manage the release of non-point source nitrogen (N) by stimulating microbial denitrification. Woodchips serve as a renewable organic carbon (C) source, yet the recalcitrance of organic C in lignocellulosic biomass causes many WBRs to be C-limited. Prior studies have observed that oxic-anoxic cycling increased the mobilization of organic C, increased nitrate (NO 3 - ) removal rates, and attenuated production of nitrous oxide (N 2 O). Here, we use multi-omics approaches and amplicon sequencing of fungal 5.8S-ITS2 and prokaryotic 16S rRNA genes to elucidate the microbial drivers for enhanced NO 3 - removal and attenuated N 2 O production under redox-dynamic conditions. Transient oxic periods stimulated the expression of fungal ligninolytic enzymes, increasing the bioavailability of woodchip-derived C and stimulating the expression of denitrification genes. Nitrous oxide reductase (nosZ) genes were primarily clade II, and the ratio of clade II/clade I nosZ transcripts during the oxic-anoxic transition was strongly correlated with the N 2 O yield. Analysis of metagenome-assembled genomes revealed that many of the denitrifying microorganisms also have a genotypic ability to degrade complex polysaccharides like cellulose and hemicellulose, highlighting the adaptation of the WBR microbiome to the ecophysiological niche of the woodchip matrix.
(© 2023 Applied Microbiology International and John Wiley & Sons Ltd.)
Databáze: MEDLINE
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