Using RNA-Stable isotope probing to investigate methane oxidation metabolites and active microbial communities in methane oxidation coupled to denitrification.

Autor: Nwoba ST; Dept. of Chemical & Process Engineering, University of Canterbury, Christchurch, New Zealand. Electronic address: sunday.nwoba@pg.canterbury.ac.nz., Carere CR; Dept. of Chemical & Process Engineering, University of Canterbury, Christchurch, New Zealand., Wigley K; Dept. of Chemical & Process Engineering, University of Canterbury, Christchurch, New Zealand., Baronian K; Dept. of Chemical & Process Engineering, University of Canterbury, Christchurch, New Zealand., Weaver L; Institute of Environmental Science and Research Ltd., Christchurch, New Zealand., Gostomski PA; Dept. of Chemical & Process Engineering, University of Canterbury, Christchurch, New Zealand. Electronic address: peter.gostomski@canterbury.ac.nz.
Jazyk: angličtina
Zdroj: Chemosphere [Chemosphere] 2024 Jun; Vol. 357, pp. 142067. Date of Electronic Publication: 2024 Apr 20.
DOI: 10.1016/j.chemosphere.2024.142067
Abstrakt: The active denitrifying communities performing methane oxidation coupled to denitrification (MOD) were investigated using samples from an aerobic reactor (∼20% O 2 and 2% CH 4 ) and a microaerobic reactor (2% O 2 , 2% CH 4 ) undertaking denitrification. The methane oxidation metabolites excreted in the reactors were acetate, methanol, formate and acetaldehyde. Using anaerobic batch experiments supplemented with exogenously supplied 13 C-labelled metabolites, the active denitrifying bacteria were identified using 16S rRNA amplicon sequencing and RNA-stable isotope probing (RNA-SIP). With the aerobic reactor (AR) samples, the maximum NO 3 - removal rates were 0.43 mmol g -1 d -1 , 0.40 mmol g -1 d -1 , 0.33 mmol g -1 d -1 and 0.10 mmol g -1 d -1 for exogenously supplied acetate, formate, acetaldehyde and methanol batch treatments respectively, while with the microaerobic reactor (MR) samples, the maximum NO 3 - removal rates were 0.41 mmol g -1 d -1 , 0.33 mmol g -1 d -1 , 0.38 mmol g -1 d -1 and 0.14 mmol g -1 d -1 for exogenously supplied acetate, formate, acetaldehyde and methanol batch treatments respectively. The RNA-SIP experiments with 13 C-labelled acetate, formate, and methanol identified Methyloversatilis, and Hyphomicrobium as the active methane-driven denitrifying bacteria in the AR samples, while Pseudoxanthomonas, Hydrogenophaga and Hyphomicrobium were the active MOD bacteria in the MR samples. Collectively, all the data indicate that formate is a key cross-feeding metabolite excreted by methanotrophs and consumed by denitrifiers performing MOD.
Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
(Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)
Databáze: MEDLINE
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