Reduction of nitric oxide catalyzed by hydroxylamine oxidoreductase from an anammox bacterium.

J Biosci Bioeng

Department of Applied Life Science, Sojo University, 4-22-1 Ikeda, Nishiku, Kumamoto 860-0082, Japan. Electronic address:

Published: December 2014

AI Article Synopsis

Article Abstract

The hydroxylamine oxidoreductase (HAO) from the anammox bacterium, Candidatus Kuenenia stuttgartiensis has been reported to catalyze the oxidation of hydroxylamine (NH2OH) to nitric oxide (NO) by using bovine cytochrome c as an oxidant. In contrast, we investigated whether the HAO from anammox bacterium strain KSU-1 could catalyze the reduction of NO with reduced benzyl viologen (BVred) and the NO-releasing reagent, NOC 7. The reduction proceeded, resulting in the formation of NH2OH as a product. The oxidation rate of BVred was proportional to the concentration of BVred itself for a short period in each experiment, a situation that was termed quasi-steady state. The analyses of the states at various concentrations of HAO allowed us to determine the rate constant for the catalytic reaction, (2.85 ± 0.19) × 10(5) M(-1) s(-1), governing NO reduction by BVred and HAO, which was comparable to that reported for the HAO from the ammonium oxidizer, Nitrosomonas with reduced methyl viologen. These results suggest that the anammox HAO functions to adjust anammox by inter-conversion of NO and NH2OH depending on the redox potential of the physiological electron transfer protein in anammox bacteria.

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.jbiosc.2014.05.018DOI Listing

Publication Analysis

Top Keywords

anammox bacterium
12
nitric oxide
8
hydroxylamine oxidoreductase
8
hao anammox
8
anammox
6
hao
6
reduction
4
reduction nitric
4
oxide catalyzed
4
catalyzed hydroxylamine
4

Similar Publications

Community assembly and succession of the functional membrane biofilm in the anammox dynamic membrane bioreactor: Deterministic assembly of anammox bacteria.

Environ Res

January 2025

State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Siping Road, Shanghai 200092, P. R. China. Electronic address:

The anammox dynamic membrane bioreactor (DMBR) exhibits potential for efficient nitrogen removal via anammox processes. The functional membrane biofilm in the anammox DMBR significantly enhances nitrogen removal, ensuring robust operation. Nevertheless, ecological mechanisms underpinning the nitrogen removal function of the membrane biofilm remain unclear.

View Article and Find Full Text PDF

Dual intermittent aerations enhance nitrogen removal via anammox in anoxic/oxic biofilm process for carbon limited wastewater treatment.

Bioresour Technol

January 2025

School of Environment and Climate, Guangdong Engineering Research Center of Water Treatment Processes and Materials, and Guangdong Key Laboratory of Environmental Pollution and Health, Jinan University, Guangzhou 510632, China; Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhuhai 519000, China.

Efficient nitrogen removal after organic capture is challenging through conventional nitrification-denitrification process. Two biofilm-based anoxic/oxic reactors, with a single intermittent zone (R1) or dual intermittent zones (R2), were compared in treating carbon-limited wastewater. Intermittent aeration integrated partial nitrification-anammox (PNA), partial denitrification-anammox (PDA), and denitrification, with anammox-related pathways contributing over 75% nitrogen removal in both reactors.

View Article and Find Full Text PDF

Deciphering intricate associations between vigorous development and novel metabolic preferences of partial denitrification/anammox granular consortia within mainstream municipal wastewater.

Bioresour Technol

January 2025

National and Local Joint Engineering Laboratory of Municipal Sewage Resource Utilization Technology, Jiangsu Collaborative Innovation Center of Technology and Material of Water Treatment, School of Environmental Science and Engineering, Suzhou University of Science and Technology, Suzhou, 215009, PR China. Electronic address:

There is limited understanding of the granular partial denitrification/anammox (PD/A) microbiota and metabolic hierarchy specific to municipal wastewater treatment, particularly concerning the multi-mechanisms of functional differentiation and granulation tendencies under high-loading shocks. Therefore, this study utilized fragmented mature biofilm as the exclusive inoculum to rapidly establish a granular PD/A system. Following long-term feeding with municipal wastewater, PD/A process reached a total nitrogen removal efficiency of 97.

View Article and Find Full Text PDF

Organic carbon can influence nitrogen removal during the anaerobic ammonia oxidation (anammox) process. Propionate, a common organic compound in pretreated wastewater, its impacts on mixotrophic anammox bacteria and the underlying mechanisms have not been fully elucidated. This study investigated the core metabolism and shift in behavior patterns of mixotrophic Candidatus Brocadia sapporoensis (AMXB) under long-term propionate exposure.

View Article and Find Full Text PDF

Quorum sensing-enhanced electron transfer in anammox consortia: A mechanism for improved resistance to variable-valence heavy metals.

J Hazard Mater

January 2025

Institute of Environmental Engineering, School of Metallurgy and Environment, Central South University, Changsha 410083,  China; Chinese National Engineering Research Center for Control & Treatment of Heavy Metal Pollution, Changsha 410083, China. Electronic address:

Quorum sensing (QS) is recognized for enhancing bacterial resistance against heavy metals by regulating the production of extracellular substances that hinder metal penetration into the intracellular environment. However, it remains unclear whether QS contributes to resistance by regulating electron transfer, thereby transforming metals from more toxic to less toxic forms. This study investigated the regulatory mechanism of acyl-homoserine lactone (AHL)-mediated QS on electron transfer under As(III) and Cr(VI) stress.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!