TY - JOUR
T1 - Exploring the microbial influence on seasonal nitrous oxide concentration in a full-scale wastewater treatment plant using metagenome assembled genomes
AU - Valk, Laura Christina
AU - Peces, Miriam
AU - Singleton, Caitlin Margaret
AU - Laursen, Mads Dyring
AU - Andersen, Mikkel Holmen
AU - Mielczarek, Artur Tomasz
AU - Nielsen, Per Halkjær
N1 - Funding Information:
The authors wish to thank the Avedøre WWTP for sharing the operational data, and all the student helpers and operators for taking the activated sludge samples. The authors additionally wish to thank Nick Green for help with the HQ MAG annotation. The project has been funded by the Villum Foundation (Dark Matter, grant 13351).
Funding Information:
The authors wish to thank the Avedøre WWTP for sharing the operational data, and all the student helpers and operators for taking the activated sludge samples. The authors additionally wish to thank Nick Green for help with the HQ MAG annotation. The project has been funded by the Villum Foundation (Dark Matter, grant 13351).
Publisher Copyright:
© 2022
PY - 2022/7
Y1 - 2022/7
N2 - Nitrous oxide is a highly potent greenhouse gas and one of the main contributors to the greenhouse gas footprint of wastewater treatment plants (WWTP). Although nitrous oxide can be produced by abiotic reactions in these systems, biological N2O production resulting from the imbalance of nitrous oxide production and reduction by microbial populations is the dominant cause. The microbial populations responsible for the imbalance have not been clearly identified, yet they are likely responsible for strong seasonal nitrous oxide patterns. Here, we examined the seasonal nitrous oxide concentration pattern in Avedøre WWTP alongside abiotic parameters, the microbial community composition based on 16S rRNA gene sequencing and already available metagenome-assembled genomes (MAGs). We found that the WWTP parameters could not explain the observed pattern. While no distinct community changes between periods of high and low dissolved nitrous oxide concentrations were determined, we found 26 and 28 species with positive and negative correlations to the seasonal N2O concentrations, respectively. MAGs were identified for 124 species (approximately 31% mean relative abundance of the community), and analysis of their genomic nitrogen transformation potential could explain this correlation for four of the negatively correlated species. Other abundant species were also analysed for their nitrogen transformation potential. Interestingly, only one full-denitrifier (Candidatus Dechloromonas phosphorivorans) was identified. 59 species had a nosZ gene predicted, with the majority identified as a clade II nosZ gene, mainly from the phylum Bacteroidota. A correlation of MAG-derived functional guilds with the N2O concentration pattern showed that there was a small but significant negative correlation with nitrite oxidizing bacteria and species with a nosZ gene (N2O reducers (DEN)). More research is required, specifically long-term activity measurements in relation to the N2O concentration to increase the resolution of these findings.
AB - Nitrous oxide is a highly potent greenhouse gas and one of the main contributors to the greenhouse gas footprint of wastewater treatment plants (WWTP). Although nitrous oxide can be produced by abiotic reactions in these systems, biological N2O production resulting from the imbalance of nitrous oxide production and reduction by microbial populations is the dominant cause. The microbial populations responsible for the imbalance have not been clearly identified, yet they are likely responsible for strong seasonal nitrous oxide patterns. Here, we examined the seasonal nitrous oxide concentration pattern in Avedøre WWTP alongside abiotic parameters, the microbial community composition based on 16S rRNA gene sequencing and already available metagenome-assembled genomes (MAGs). We found that the WWTP parameters could not explain the observed pattern. While no distinct community changes between periods of high and low dissolved nitrous oxide concentrations were determined, we found 26 and 28 species with positive and negative correlations to the seasonal N2O concentrations, respectively. MAGs were identified for 124 species (approximately 31% mean relative abundance of the community), and analysis of their genomic nitrogen transformation potential could explain this correlation for four of the negatively correlated species. Other abundant species were also analysed for their nitrogen transformation potential. Interestingly, only one full-denitrifier (Candidatus Dechloromonas phosphorivorans) was identified. 59 species had a nosZ gene predicted, with the majority identified as a clade II nosZ gene, mainly from the phylum Bacteroidota. A correlation of MAG-derived functional guilds with the N2O concentration pattern showed that there was a small but significant negative correlation with nitrite oxidizing bacteria and species with a nosZ gene (N2O reducers (DEN)). More research is required, specifically long-term activity measurements in relation to the N2O concentration to increase the resolution of these findings.
KW - Full-scale WWTP
KW - Genomes
KW - Metagenomics
KW - Nitrous oxide
KW - Time-series
KW - Greenhouse Gases/analysis
KW - Nitrous Oxide/analysis
KW - RNA, Ribosomal, 16S/genetics
KW - Nitrogen/analysis
KW - Water Purification
KW - Denitrification
KW - Seasons
KW - Metagenome
UR - http://www.scopus.com/inward/record.url?scp=85130134439&partnerID=8YFLogxK
U2 - 10.1016/j.watres.2022.118563
DO - 10.1016/j.watres.2022.118563
M3 - Journal article
C2 - 35594748
AN - SCOPUS:85130134439
SN - 0043-1354
VL - 219
JO - Water Research
JF - Water Research
M1 - 118563
ER -