好氧氨氧化微生物系统发育及生理生态学差异

Differences between ammonia-oxidizing microorganisms in phylogeny and physiological ecology

摘要:

作为好氧氨氧化的驱动者，氨氧化古菌(Ammonia-oxidizing archaea，AOA)和细菌(Ammonia-oxidizing bacteria，AOB)一直是氮的生物地球化学循环的研究热点之一。由于它们的相对丰度、群落结构和活性因环境而异，目前二者对全球氮循环的相对贡献仍存在争议。对培养物和环境样品的动力学、基因组学等研究结果表明，这种差异主要是由AOA和AOB的生理生态学差异导致的。氨浓度、pH、溶氧、温度等环境因素以及代谢途径等生理因素导致AOA和AOB的生态位分化。通过比较AOA和AOB在系统发育、对环境因子的响应以及代谢途径等方面的差异，对好氧氨氧化微生物相关研究成果进行概括和总结，以便深入了解它们在不同环境中对氮循环的相对贡献；同时对好氧氨氧化微生物今后的研究重点进行了展望。

Abstract:

The roles of ammonia-oxidizing bacteria (AOB) and ammonia-oxidizing archaea (AOA), as drivers of ammonia oxidation, in nitrogen cycle have been one of the most attractive topic in the field of microbial ecology. The relative importance of AOA and AOB in nitrogen cycle currently is still under debate since significant variations in the relative abundance, community structure and activity between them under different environmental conditions were observed. This discrepancy could be attributed to differences in the physiological ecology of AOA and AOB as evidenced by kinetics and genomes of cultures and environmental samples studies. Metabolic pathway and environmental factors like ammonia concentration, pH, dissolved oxygen and temperature were potential factors causing niche differentiation between AOA and AOB. Here, current knowledge of differences in the physiology, phylogeny, environmental responses and metabolic pathway between AOA and AOB were summarized, in order to gain deep insight into their relative contribution to nitrogen cycling under different environments. Finally, the future perspectives of AOA and AOB were proposed.