The availability of whole-genome sequences for ammonia-oxidizing bacteria (AOB) has led to dramatic increases in our understanding of these environmentally important microorganisms. Their genomes are smaller than many other members of the proteobacteria and may indicate genome reductions consistent with their limited lifestyle. The genomes have a surprising level of gene repetition including genes for ammonia catabolism, iron acquisition, and insertion sequences. The gene profiles reveal limited genes for catabolism and transport of complex organic compounds, but complete pathways for some other compounds. This led to the observation of chemolithoheterotrophic growth of Nitrosomonas europaea. Genes for sucrose synthesis/degradation were identified. The core metabolic module of aerobic ammonia oxidation, the extraction of electrons from hydroxylamine to generate proton-motive force and reductant, has evolutionary roots in the denitrification inventory of anaerobic sulfur-dependent bacteria. The extension by ammonia monooxygenase provides a mechanism to feed this module using ammonia and O(2).

中文翻译：

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基因组分析对我们了解氨氧化细菌的影响。

氨氧化细菌（AOB）的全基因组序列的可用性已导致我们对这些对环境重要的微生物的理解有了极大的提高。它们的基因组比变形杆菌的许多其他成员都要小，并且可能表明基因组的减少与其有限的生活方式相一致。基因组具有令人惊讶的基因重复水平，包括氨分解代谢，铁捕获和插入序列的基因。基因图谱揭示了复杂的有机化合物分解代谢和运输的有限基因，但是某些其他化合物的完整途径。这导致了欧洲亚硝化单胞菌的化学异养生长的观察。鉴定了蔗糖合成/降解的基因。好氧氨氧化的核心代谢模块 从羟胺中提取电子以产生质子动力和还原剂，在厌氧硫依赖性细菌的反硝化过程中具有进化的根源。氨单加氧酶的延伸提供了一种使用氨和O（2）填充该模块的机制。