Phylogenetic analysis of nitric oxide reductase gene homologues from aerobic ammonia-oxidizing bacteria
Phylogenetic analysis of nitric oxide reductase gene homologues from aerobic ammonia-oxidizing bacteria
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DOI：
10.1016/j.femsec.2004.11.002
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发表时间：
2005-04-01
影响因子：
4.2
通讯作者：
Ward, BB
中科院分区：
文献类型：
--
作者：
Casciotti, KL;Ward, BB
一氧化氮(NO)和一氧化二氮(N2O)是由硝化细菌和反硝化细菌产生的具有重要气候意义的微量气体。在反硝化过程中，一氧化氮(NO)通过一氧化氮合酶(NOR)产生N2O。氨氧化细菌亚硝酸单胞菌也具有功能性的一氧化氮还原酶，最近被证明具有独特的功能。在这项研究中，从另外8株氨氧化细菌中获得了与一氧化氮合酶大亚基(Norb)同源的序列，其中包括亚硝化单胞菌和亚硝化球菌种(即β和伽马变形杆菌氨氧化菌)，表明在氨氧化细菌中广泛存在Norb同源物。然而，尽管努力从亚硝酸螺旋体菌株中检测Norb同源物，但尚未获得序列。系统发育分析将硝化菌Norb同系物归入一个亚簇，与反硝化菌序列不同。这些序列的相似和不同突出了理解由单个同源基因的存在所定义的“功能群”中所代表的代谢的多样性的必要性。这些结果扩展了硝化细菌Norb同源序列的数据库。(C)2004年欧洲微生物学会联合会。爱思唯尔出版，版权所有。
Nitric oxide (NO) and nitrous oxide (N2O) are climatically important trace gases that are produced by both nitrifying and denitrifying bacteria. In the denitrification pathway, N2O is produced from nitric oxide (NO) by the enzyme nitric oxide reductase (NOR). The ammonia-oxidizing bacterium Nitrosomonas europaea also possesses a functional nitric oxide reductase, which was shown recently to serve a unique function. In this study, sequences homologous to the large subunit of nitric oxide reductase (norB) were obtained from eight additional strains of ammonia-oxidizing bacteria, including Nitrosomonas and Nitrosococcus species (i.e., both beta- and gamma-Proteobacterial ammonia oxidizers), showing widespread occurrence of a norB homologue in ammonia-oxidizing bacteria. However, despite efforts to detect norB homologues from Nitrosospira strains, sequences have not yet been obtained. Phylogenetic analysis placed nitrifier norB homologues in a subcluster, distinct from denitrifier sequences. The similarities and differences of these sequences highlight the need to understand the variety of metabolisms represented within a "functional group" defined by the presence of a single homologous gene. These results expand the database of norB homologue sequences in nitrifying bacteria. (c) 2004 Federation of European Microbiological Societies. Published by Elsevier B.V. All rights reserved.