Related Experiment Video
Updated: Feb 17, 2026

A Novel Bioreactor for High Density Cultivation of Diverse Microbial Communities
Published on: December 25, 2015
Heterotrophic nitrogen removal in Bacillus sp. K5: involvement of a novel hydroxylamine oxidase
Yunlong Yang1, Ershu Lin1, Shaobin Huang2
1College of Life Science, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
Abstract:
An aerobic denitrifying bacterium isolated from a bio-trickling filter treating NOx, Bacillus sp. K5, is able to convert ammonium to nitrite, in which hydroxylamine oxidase (HAO) plays a critical role. In the present study, the performance for simultaneous nitrification and denitrification was investigated with batch experiments and an HAO was purified by an anion-exchange and gel-filtration chromatography from strain K5. The purified HAO's molecular mass was determined by SDS-PAGE and its activity by measuring the change in the concentration of ferricyanide, the electron acceptor. Results showed that as much as 87.8 mg L-1 ammonium-N was removed without nitrite accumulation within 24 hours in the sodium citrate medium at C/N of 15. The HAO isolated from the strain K5 was approximately 71 KDa. With hydroxylamine (NH2OH) as a substrate and potassium ferricyanide as an electron acceptor, the enzyme was capable of oxidizing NH2OH to nitrite in vitro when the pH varied from 7 to 9 and temperature ranged from 25 °C to 40 °C. This is the first time that an HAO has been purified from the Bacillus genus, and the findings revealed that it is distinctive in its molecular mass and enzyme properties.
More Related Videos
08:05Measurement of the Potential Rates of Dissimilatory Nitrate Reduction to Ammonium Based on 14NH4+/15NH4+ Analyses via Sequential Conversion to N2O
Published on: October 7, 2020
09:27Immobilization of Multi-biocatalysts in Alginate Beads for Cofactor Regeneration and Improved Reusability
Published on: April 22, 2016
Related Concept Videos
Inorganic Nitrogen Assimilation
Metabolism of Chemolithotrophs
Overview of Nitrogen Metabolism
The largest pool of nitrogen available in the terrestrial ecosystem is gaseous nitrogen (N2) from the air, but this...
Amino Acid Catabolism
Bioremediation
Microbial Nutrition