Metabolism of Inorganic N Compounds by Ammonia-Oxidizing Bacteria

Authors: Arp, Daniel¹; Stein, Lisa²

Source: Critical Reviews in Biochemistry and Molecular Biology, Volume 38, Number 6, October-November 2003 , pp. 471-495(25)

Publisher: Informa Healthcare

Buy & download fulltext article:

Price: $34.29 plus tax (Refund Policy)

Abstract:

Ammonia oxidizing bacteria extract energy for growth from the oxidation of ammonia to nitrite. Ammonia monooxygenase, which initiates ammonia oxidation, remains enigmatic given the lack of purified preparations. Genetic and biochemical studies support a model for the enzyme consisting of three subunits and metal centers of copper and iron. Knowledge of hydroxylamine oxidoreductase, which oxidizes hydroxylamine formed by ammonia monooxygenase to nitrite, is informed by a crystal structure and detailed spectroscopic and catalytic studies. Other inorganic nitrogen compounds, including NO, N 2 O, NO 2 , and N 2 can be consumed and/or produced by ammonia-oxidizing bacteria. NO and N 2 O can be produced as byproducts of hydroxylamine oxidation or through nitrite reduction. NO 2 can serve as an alternative oxidant in place of O 2 in some ammonia-oxidizing strains. Our knowledge of the diversity of inorganic N metabolism by ammonia-oxidizing bacteria continues to grow. Nonetheless, many questions remain regarding the enzymes and genes involved in these processes and the role of these pathways in ammonia oxidizers.

Keywords: Ammonia monooxygenase; hydroxylamine oxidoreductase; Nitrosomonas europaea; nitrite reductase; N cycle; nitrification

Document Type: Research article

DOI: http://dx.doi.org/10.1080/10409230390267446

Affiliations: 1: Department of Botany and Plant Pathology, Oregon State University, Corvallis, OR, 97331, USA 2: Department of Environmental Sciences, University of California-Riverside, Riverside, CA, 92521, USA

Publication date: 2003-10-01

More about this publication?