Mutational analysis of the multicopy hao gene coding for hydroxylamine oxidoreductase in nitrosomonas sp. Strain ENI-11

Abstract

The ammonia-oxidizing bacterium Nitrosomonas sp. strain ENI-11 contains three copies of the hao gene (hao 1, hao 2, and hao 3) coding for hydroxylamine oxidoreductase (HAO). Three single mutants (hao1::kan, hao 2::kan, or hao 3::kan) had 68 to 75% of the wild-type growth rate and 58 to 89% of the wild-type HAO activity when grown under the same conditions. A double mutant (hao 1::kan and hao 3::amp) also had 68% of the wild-type growth and 37% of the wild-type HAO activity. © 2000, Taylor & Francis Group, LLC. All rights reserved.