摘要
氧化亚氮(N2O)的产生和消耗对气候变化有着重要影响。土壤是大气N2O的重要来源,占全球N2O总产量的60%左右,土壤表面的N2O排放是N2O产生和还原过程的结果。近年来发现土壤不仅能够产生和排放N2O气体,还具有吸收和消耗N2O的能力。土壤中N2O通过被动扩散和气体对流在土壤结构中移动,然后经过物理、化学、生物等多种途径被消耗,相比较于其他消耗途径,由微生物介导的生物途径才能真正将N2O还原转化为无害的N2,这一过程只有反硝化菌中的nosZ基因编码的氧化亚氮还原酶(N2OR)才能催化进行。近年来部分研究者揭示了一类新型nosZ基因(非典型nosZⅡ基因),其丰度和类型也影响着N2O还原潜力。土壤微生物需要在适宜的环境条件下活动,土壤环境的改变也会影响土壤N2O还原和消耗的能力。文章以土壤微生物消耗N2O过程为核心,论述了土壤水分含量、土壤碳/氮含量、土壤深度、土壤类型、土壤pH值等关键因子对土壤中N2O还原微生物活性的影响机理,以及对N2O消耗能力和排放过程的调节机制。从而深入认识N2O微生物消耗能力及其调控机制,并为控制土壤温室气体N2O的排放、氮转化过程和提高氮素利用效率提供参考依据。
The production and consumption of nitrous oxide(N2O) has an important impact on climate change.Soil is an important source of atmospheric N2O, accounting for about 60% of the global N2O production. N2O emissions from the soil surface are the result of N2O production and reduction processes.In recent years, it has been found that soil not only produces and emits N2O gas, but also has the ability to absorb and consume N2O.N2O in the soil moves through the soil structure through passive diffusion and gas convection, and is then consumed through various ways such as physical, chemical, and biological.Compared with other consumption pathways, the biological pathway mediated by microorganisms can truly reduce N2O into harmless N2,This process can only be catalyzed by the nitrous oxide reductase(N2OR) encoded by the nosZ gene in denitrifying bacteria.In recent years, some researchers have revealed a new class of nosZ genes(atypical nosZ Ⅱ genes) whose abundance and type also affect the N2O reduction potential.Soil microbes need to be active under suitable environmental conditions, and changes in soil environment can also affect soil N2O reduction and consumption.The core of this paper is the process of soil microorganisms consuming N2O,the effects of key factors such as soil moisture content, soil carbon/nitrogen content, soil depth, soil type and soil p H on the activity of N2O reducing microorganisms in soil were discussed, as well as the regulation mechanism of N2O consumption capacity and emission process.So as to deeply understand the N2O microbial consumption capacity and its regulatory mechanism, and provide reference for controlling the emission of soil greenhouse gas N2O, nitrogen conversion process and improving nitrogen utilization efficiency.
作者
宋雅琦
王玲
李昆
公勤
李兆华
李家轩
SONG Yaqi;WANG Ling;LI Kun;GONG Qin;LI Zhaohua;LI Jiaxuan(College of Resources and Environment,Hubei University,Wuhan 430062,China)
出处
《环境科学与技术》
CAS
CSCD
北大核心
2019年第9期82-90,共9页
Environmental Science & Technology
基金
中国博士后科学基金面上项目（2017M622386）
国家自然科学基金（41807043）
湖北省自然基金创新群体项目（2016CFA016）
