降氨除臭芽孢杆菌的筛选鉴定及其氮素迁移过程

Identification and nitrogen migration of an ammonia-oxidizing and deodorizing Bacillus

摘要:

【目的】分离和鉴定一株高效降氨除臭芽孢杆菌，并研究其氮素迁移过程。【方法】采用自行设计的筛选平台，根据菌落形态、生理生化特征及16S rRNA基因序列的系统进化树分析进行菌株鉴定；在好氧和厌氧条件下，以NH4+-N为唯一氮源，通过检测NH4+-N、NO2?-N、NO3?-N和产生的气体浓度，明确菌株在降氨过程中氮素的迁移过程及特点。【结果】筛选出一株高效降氨除臭芽孢杆菌，经生化与分子鉴定为凝结芽孢杆菌；其在好氧条件下将NH4+-N降解为NO3?-N，降解率为98%；同时少量NO3?-N经好氧反硝化作用还原为N2；在厌氧条件下进行了硝化作用，但NH4+-N降解率仅为23.7%，且反硝化过程不明显。【结论】筛选得到的高效降氨除臭凝结芽孢杆菌在好氧和厌氧条件下皆具有异养硝化作用，但厌氧条件下反硝化作用不显著，好氧反硝化作用产生的含氮气体为氮气，其在农业和环保领域具有巨大的产业化潜力。

Abstract:

[Objective] to get a deodorizing bacillus of high efficient ammonia degradation, and to investigate the process of the nitrogen migration of the strain. [Methods] An ammonia-oxidizing strain was screened in a self-designed screening platform. Colonial morphology, physio-biochemical tests and 16S rRNA gene sequence analysis were adopted to determine the phylogenetic position of the isolated strain. The nitrogen migration characteristics and process of the strain that cultured by NH4Cl as the sole nitrogen source were investigated by using the chemical detection of NH4+-N, NO2?-N, NO3?-N and gases under aerobic and anaerobic conditions. [Results] A high efficient ammonia-oxidizing and deodorizing strain that has the characteristics of heterotrophic nitrification and aerobic denitrification was screened and identified as Bacillus coagulans. Under aerobic and anaerobic conditions, the NH4+-N oxidizing rate of the strain RJCC-03 could reach 98% and 23.7%, respectively. A small amount of N2, not nitrogen oxides gases, was generated during the experiment process, under aerobic conditions. [Conclusion] These results proved Bacillus coagulans had great potential application in the agricultural and environmental protection.