High microbial diversity of the nitric oxide dismutation reaction revealed by PCR amplification and analysis of the nod gene

• Published in: International biodeterioration & biodegradation Vol. 143; p. 104708
• Main Authors: Hu, Qian-Qian, Zhou, Zhi-Chao, Liu, Yi-Fan, Zhou, Lei, Mbadinga, Serge Maurice, Liu, Jin-Feng, Yang, Shi-Zhong, Gu, Ji-Dong, Mu, Bo-Zhong
• Format: Journal Article
• Language: English
• Published: Barking Elsevier Ltd 01.09.2019; Elsevier BV
• Subjects: Distribution; Ecosystems; Environmental samples; Gene sequencing; Information processing; Microorganisms; N-removal; Nitric oxide; Nitric oxide dismutase; Nitrogen; Nitrogen cycle; Nod protein; Oil pollution; Oil reservoirs; Phylogeny; Reservoirs; rRNA 16S; Sediment pollution; Sludge; Soil contamination; Soil pollution; Soils; Taxonomy; Wastewater pollution; Wastewater treatment; Wastewater treatment plants; Water treatment; Nitric oxide dismutase; Environmental samples; Distribution; N-removal
• ISSN: 0964-8305; 1879-0208
• DOI: 10.1016/j.ibiod.2019.05.025

Microbial nitric oxide dismutation reaction (NOD), involved in the biogeochemical nitrogen cycle on Earth, has been implemented to N removal in laboratory-scale wastewater treatment systems, but microorganisms from relatively a few lineages have been implicated to be associated with this biochemical process. Detection of abundant putative (or novel) nitric oxide dismutase-encoding gene PCR products could confer the diversity of nitric oxide dismutase in additional microbial groups other than the two known lineages, but the distribution pattern of nod gene is unclear in different environments including oil reservoirs. Here, we surveyed the distribution and diversity of nod genes by clone library sequencing together with the inference of 16S rRNA gene-based taxonomy by amplicon sequencing in diverse samples including wastewater treatment plants (WWTP), wetland, hydrocarbon-contaminated soil, and oil reservoirs. A total of 730 phylogenetically diverse nod-related sequences recovered from these samples were clustered into 42 operational taxonomic units (OTUs) showing a considerably high diversity of nod gene in these different ecosystems. The abundance of nod gene in five environmental samples were ∼1.80 × 107–2.62 × 108 copies g−1 soil (sludge) and ∼9.67 × 106 copies l−1 water. The dominant microorganisms were Bacteroidetes, Firmicutes, Actinobacteria, and Chloroflexi. Our results expanded significantly the diversity of microbial groups potentially involved in nitric oxide dismutation, suggesting the ubiquity of microbial members in the different ecosystems carrying out NO dismutation reaction. Further studies on the functional capacity of this new microbial group will advance a better understanding of the microbially-driven nitrogen cycling and provide thorough information on N-removal processes and potential applications. [Display omitted] •Diversity and abundance of putative nod genes were detected in diverse environmental samples.•A comprehensive survey of the NO dismutation reaction in environments was performed.•Putative nod genes were successfully detected from hydrocarbon-contaminated soil.