一株兼性氧化亚氮还原菌的还原N2O能力

Capability of N_2O reduction of a facultative N_2O reducer

【目的】从水稻土中分离筛选出一株兼性氧化亚氮还原菌,并探索其在不同条件下还原N_2O的能力,为减少温室气体N_2O的排放提供重要依据。【方法】通过微生物富集培养分离技术从水稻土中分离得到纯菌;利用nosZ基因和16S rRNA的测序分析鉴定菌株;通过测定菌株在不同条件下N_2O的还原量,分析该菌株还原N_2O的能力及调控因子。【结果】经鉴定,该菌株含有nos Z基因,属于假单胞菌属,在温度30°C、厌氧条件下还原N_2O速率高达0.0219μmol/min以上,改变不同温度和氧气浓度后其能力相对减弱,但仍具备较强的还原N_2O作用。【结论】从水稻土中分离筛选得到的兼性氧化亚氮还原菌为假单胞菌,它在不同环境条件下都具备较强的还原N_2O能力,该菌株可能为减少土壤N_2O排放提供新途径,对保障生态环境安全具有重要的应用价值。

[Objective] A nitrous oxide reducing bacterium（DJ7） was isolated from paddy soil and its ability to reduce N2O was detected under different incubation conditions. Aiming to understand the mechanisms of N2O reduction and supply theoretical basis for regulation of N2O emission. [Methods] The strain was isolated by microbial enrichment culture and identified by homogeneous analysis of its sequences of nos Z and 16 S r RNA gene with the database of NCBI. The abilities of N2O-reducing of DJ7 at different temperatures and O2 concentrations were determined by measuring the amount of N2O reduction through GC. [Results] The strain was characterized asPseudomonas and contained nos Z gene, its N2O reduction rate was more than 0.0219 μmol/min under anaerobic at 30 °C. Although the increase of air O2 concentration and shifts of incubation temperature at either direction resulted decreases of the capability of N2O reduction, it maintained a certain ability in N2O reduction. [Conclusion] The strain is an active facultative N2O reducer belonging to Pseudomonas and possesses strong ability to reduce N2O, especially under anaerobic condition. This strain may provide a new idea to alleviate the N2O issue and play an active role in the ecological environment.