Incomplete Denitrification Phenotypes in Diverse Thermus Species From Diverse Geothermal Spring Sediments and Adjacent Soils in Southwest China

Authors

Chrisabelle C. Mefferd, University of Nevada, Las Vegas
Enmin Zhou, University of Nevada, Las Vegas
Cale O. Seymour, University of Nevada, Las Vegas
Noel A. Bernardo, University of Nevada, Las Vegas
Shreya Srivastava, Miami University
Amanda J. Bengtson, University of Nevada, Las Vegas
Jian-Yu Jiao, Sun Yat-Sen University
Hailiang Dong, Miami University
Wen-Jun Li, Sun Yat-Sen University
Brian P. Hedlund, University of Nevada, Las Vegas

Document Type

Article

Publication Date

7-8-2022

Publication Title

Extremophiles

Volume

26

Issue

23

First page number:

1

Last page number:

13

Abstract

A few members of the bacterial genus Thermus have been shown to be incomplete denitrifiers, terminating with nitrite (NO2⁻) or nitrous oxide (N2O). However, the denitrification abilities of the genus as a whole remain poorly characterized. Here, we describe diverse denitrification phenotypes and genotypes of a collection of 24 strains representing ten species, all isolated from a variety of geothermal systems in China. Confirmed terminal products of nitrate reduction were nitrite or N2O, while nitric oxide (NO) was inferred as the terminal product in some strains. Most strains produced N2O; complete denitrification was not observed. Denitrification phenotypes were largely consistent with the presence of denitrification genes, and strains of the same species often had the same denitrification phenotypes and largely syntenous denitrification gene clusters. Genes for nirS and nirK coexisted in three Thermus brockianus and three Thermus oshimai genomes, which is a unique hallmark of some denitrifying Thermus strains and may be ecologically important. These results show that incomplete denitrification phenotypes are prominent, but variable, within and between Thermus species. The incomplete denitrification phenotypes described here suggest Thermus species may play important roles in consortial denitrification in high-temperature terrestrial biotopes where sufficient supply of oxidized inorganic nitrogen exists.

Keywords

Denitrifcation; Thermus; Nitrous oxide; Nitrate; Geothermal spring; Hot spring; Anaerobic respiration; Thermophiles

Disciplines

Life Sciences

File Format

PDF

File Size

1447 KB

Language

English

Rights

IN COPYRIGHT. For more information about this rights statement, please visit http://rightsstatements.org/vocab/InC/1.0/

Creative Commons License

This work is licensed under a Creative Commons Attribution 4.0 License.

Repository Citation

Mefferd, C. C., Zhou, E., Seymour, C. O., Bernardo, N. A., Srivastava, S., Bengtson, A. J., Jiao, J., Dong, H., Li, W., Hedlund, B. P. (2022). Incomplete Denitrification Phenotypes in Diverse Thermus Species From Diverse Geothermal Spring Sediments and Adjacent Soils in Southwest China. Extremophiles, 26(23), 1-13.
http://dx.doi.org/10.1007/s00792-022-01272-1