Department of Applied Life Science, Faculty of Biotechnology and Life Science, Sojo University, 4-22-1 Ikeda, Kumamoto 860-0082, Japan.
FEBS Lett. 2012 Jun 4;586(11):1658-63. doi: 10.1016/j.febslet.2012.04.041. Epub 2012 May 2.
Anaerobic ammonium oxidation (anammox) and denitrification are two distinct microbial reactions relevant to the global nitrogen cycle. The proposed initial step of the anammox reactions, reduction of nitrite to nitric oxide, has been postulated to be identical to that in denitrification catalyzed by the dissimilatory nitrite reductase of the cytochrome cd(1)-type. Here, we characterized the copper-containing nitrite reductase homolog encoded by nirK detected in the genome of an anammox bacterium strain KSU-1. We hypothesize that this NirK-type nitrite reductase, rather than a nitrite reductase of the cytochrome cd(1)-type (NirS), is likely to catalyze nitrite reduction in anammox organism KSU-1.
厌氧氨氧化（anammox）和反硝化是与全球氮循环相关的两个截然不同的微生物反应。厌氧氨氧化反应的最初步骤，即亚硝酸盐还原为一氧化氮，据推测与细胞色素 cd(1)-型异化亚硝酸盐还原酶催化的反硝化反应相同。在这里，我们对在 anammox 细菌菌株 KSU-1 基因组中检测到的 nirK 编码的含铜亚硝酸盐还原酶同源物进行了表征。我们假设这种 NirK 型亚硝酸盐还原酶而不是细胞色素 cd(1)-型的亚硝酸盐还原酶（NirS）可能催化 anammox 生物体 KSU-1 中的亚硝酸盐还原。
