氢自养微生物的驯化及其反硝化特性研究  

Cultivation of hydrogenotrophic microorganisms and the denitrification characteristics

作　　者：彭科 欧阳泽坪 吴晓燕 王红帅 杨柯 叶坚 大贯敏彦 PENG Ke;OUYANG Zeping;WU Xiaoyan;WANG Hongshuai;YANG Ke;YE Jian;OHNUKI Toshihiko(School of Resource,Environment and Safety Engineering,University of South China,Hengyang 421001,Hunan,China;Hengyang Key Laboratory of Soil Contamination Control and Remediation,Hengyang 421001,Hunan,China;Hunan Province Engineering Research Center of Radioactive Control Technology in Uranium Mining and Metallurgy,Hengyang 421001,Hunan,China;Laboratory for Advanced Nuclear Energy,Institute of Innovative Research,Tokyo Institute of Technology,Tokyo 152-8550,Japan)

机构地区：[1]南华大学资源环境与安全工程学院,湖南衡阳421001 [2]衡阳市土壤污染控制与修复重点实验室,湖南衡阳421001 [3]湖南省铀尾矿库退役治理技术工程技术研究中心,湖南衡阳421001 [4]东京工业大学科学技术创成研究院,日本东京152-8550

出　　处：《微生物学报》2023年第2期821-833,共13页Acta Microbiologica Sinica

基　　金：湖南省教育厅科学研究项目-优秀青年项目(20B505);南华大学博士启动经费(190XQD067);大学生创新创业训练计划(X202210555245)。

摘　　要：【目的】本研究筛选出弱酸性环境下利用无机碳源进行高效脱氮的氢自养微生物,探究不同无机碳源对体系反硝化能力的影响,以及长期驯化过程中反应器内水质参数、微生物群落结构和脱氮周期变化规律。【方法】氢自养微生物的驯化采用一种成本低廉、气密性优良、可计算氢气利用率的序批式反应器,通过及时向装置内补充氢气、无机碳源、营养液和硝酸盐对微生物进行连续驯化。【结果】驯化的微生物利用NaHCO_(3)和CO_(2)作为混合无机碳源对硝酸盐的脱氮效果要优于单一使用NaHCO_(3);在环境温度为20℃,pH为6.3-7.0,硝态氮初始投加量为15 mg-N/L时,NO_(3)--N最高反应速率为1.374 mg-N/(L·h),氢气最高利用率为43.4%,脱氮周期为16 h,且脱氮过程中无亚硝酸盐积累;驯化得到的微生物主要为嗜酸菌属(Acidovorax),占比达84.4%。【结论】利用本研究的装置和驯化方法对土著微生物进行脱氮驯化是可行且高效的,可筛选出在弱酸性环境下利用无机碳源进行反硝化的氢自养微生物,为地下水中硝酸盐污染的生物修复提供理论依据,也为后续进一步研究弱酸性环境下氢自养微生物同时脱氮固铀奠定基础。[Objective]We screened out hydrogenotrophic microorganisms using inorganic carbon sources for high efficiency in denitrification under weak acidic conditions,to investigate the effects of different inorganic carbon sources on the denitrification capacity of the system,and to explore the variation in water quality parameters,microbial community structure,and denitrification cycle in the reactor during long-term cultivation.[Methods]We developed a sequential batch reactor for continuous cultivation of microorganisms by supplying hydrogen,inorganic carbon source,nutrient solution and nitrate in time,and the apparatus have the advantages of low cost,excellent air tightness,and hydrogen utilization rate calculation.[Results]The cultivated microorganisms showed higher efficiency in denitrifying nitrates with the mixture of NaHCO_(3)and CO_(2)as inorganic carbon sources than that of NaHCO_(3)as solo carbon source.Under the conditions of ambient temperature of 20℃,pH of 6.3-7.0,and initial nitrate nitrogen dosage of 15 mg-N/L,the highest reaction rate of NO_(3)--N was 1.374 mg-N/(L·h)and the highest utilization rate of hydrogen was 43.4%.In addition,the denitrification cycle was 16 h,with no nitrite accumulation detected.The cultivated microorganisms were mainly Acidovorax,accounting for 84.4%.[Conclusion]It is feasible and efficient to use this apparatus and method to cultivate microorganisms.Hydrogenotrophic microorganisms could be screened for denitrification by inorganic carbon source under weak acidic condition.The findings lay a theoretical basis for the bioremediation of groundwater polluted by nitrate and a foundation for the simultaneous denitrification and uranium fixation of hydrogenotrophic microorganisms in acidic environment in the near future.

关 键 词：氢自养反硝化 碳酸氢钠 二氧化碳 硝酸盐 亚硝酸盐 微生物群落 

分 类 号：Q935[生物学—微生物学]