中文摘要：

氧化亚氮（N20）是一种强力温室气体，能够破坏臭氧层。微生物含有的nosZ基因能够编码氧化亚氮还原酶，该酶可还原N20成为无害的N2，因而对环境中nosZ基因的研究成为气候变化研究的一个热点。最近研究者对全基因组序列分析的结果揭示了一类新型nosZ基因（非典型nosZⅡ基因）存在于更为广泛和多样的氮代谢微生物当中，这类nosZ编码的蛋白能够起到氧化亚氮还原酶的作用，并且广泛存在于多样的自然环境中。然而，针对含有非典型nosZⅡ基因的微生物的相关研究还很不全面，这类微生物发挥作用的环境条件以及在N2O还原过程中的特性仍然未知。本文主要综述了非典型nosZⅡ基因与典型nosZI的主要差异、在环境中的分布情况以及未来研究方向的展望等。

英文摘要：

Nitrous oxide （N2O） is a powerful greenhouse gas which can destroy the ozone layer. Nitrous oxide reductase coded by nosZ gene in microorganisms, can reduce N2O to harmless N2, thus the study on nosZ gene in the environments becomes a research hotspot. A recent study of genome sequence comparative analysis revealed that a new class of nosZ gene （atypical nosZ Ⅱ gene） is present in diverse nitrogen metabolism microbes. This type of nosZ gene encodes a functional nitrous oxide reductase and is found in variety of natural environments. However, the research on microbes containing atypical nosZ II genes is still incomplete, and the environmental conditions in which these microorganisms act and characteristics of N2O reduction process is still unknown. This paper reviews the differences between atypical nosZ Ⅱ and typical nosZ I, and their distribution in environment. We also propose the direction of future research on the nosZ Ⅱ gene.