Stoichiometric and kinetic characterization of an acid-tolerant ammonia oxidizer ‘Candidatus Nitrosoglobus’

Research output: Journal Publications and ReviewsRGC 21 - Publication in refereed journalpeer-review

22 Scopus Citations
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Author(s)

  • Zhiyao Wang
  • Gaofeng Ni
  • Nova Maulani
  • Jun Xia
  • Haydée De Clippeleir
  • Shihu Hu
  • Min Zheng

Detail(s)

Original languageEnglish
Article number117026
Journal / PublicationWater Research
Volume196
Online published9 Mar 2021
Publication statusPublished - 15 May 2021
Externally publishedYes

Abstract

Recently, acidic (i.e. pH<5) nitrification in activated-sludge is attracting attention because it enables stable nitritation (NH4+ → NO2-), and enhances sludge reduction and stabilization. However, the key acid-tolerant ammonia oxidizers involved are poorly understood. In this study, we performed stoichiometric and kinetic characterization of a new acid-tolerant ammonia-oxidizing bacterium (AOB) belonging to gamma-proteobacterium, Candidatus Nitrosoglobus. Ca. Nitrosoglobus was cultivated in activated-sludge in a laboratory membrane bioreactor over 200 days, with a relative abundance of 55.1 ± 0.5% (indicated by 16S rRNA gene amplicon sequencing) at the time of the characterization experiments. Among all known nitrifiers, Ca. Nitrosoglobus bears the highest resistance to nitrite, low pH, and free nitrous acid (FNA). These traits define Ca. Nitrosoglobus as an adversity-strategist that tends to prosper in acidic activated-sludge, where the low pH (< 5.0) and high levels of FNA (at parts per million levels) sustained and inhibited all other nitrifiers. In contrast, in the conventional pH-neutral activated-sludge process, Ca. Nitrosoglobus is less competitive with canonical AOB (e.g. Nitrosomonas) due to the relatively slow specific growth rate and low affinities to both oxygen and total ammonia. These results advance our understanding of acid-tolerant ammonia oxidizers, and support further development of the acidic activated-sludge process in which Ca. Nitrosoglobus can play a critical role. © 2021 Elsevier Ltd.

Research Area(s)

  • Acid-tolerant, Acidic, Ammonia oxidizing bacteria, Candidatus Nitrosoglobus, Kinetics, Stoichiometry

Citation Format(s)

Stoichiometric and kinetic characterization of an acid-tolerant ammonia oxidizer ‘Candidatus Nitrosoglobus’. / Wang, Zhiyao; Ni, Gaofeng; Maulani, Nova et al.
In: Water Research, Vol. 196, 117026, 15.05.2021.

Research output: Journal Publications and ReviewsRGC 21 - Publication in refereed journalpeer-review