甲烷厌氧氧化协同硝酸盐还原菌群驯化及其群落特征

伴随硝酸盐还原的甲烷厌氧氧化是协同减少环境中硝酸盐及甲烷的有效途径.利用实验室废水处理厌氧污泥、污水处理厂厌氧污泥和填埋场覆土驯化富集硝酸盐还原型甲烷厌氧氧化菌群.考察菌群的甲烷氧化效果,结果发现接种污水处理厂厌氧污泥体系甲烷转化量最大,为0.05 mg·d-1.微生物群落结构分析显示,该体系中甲烷微菌和甲烷八叠球菌是甲烷氧化菌,假单胞菌、梭状芽胞杆菌和热单胞菌参与了硝酸盐的还原反应.硝酸盐的量影响甲烷的转化率及菌群结构.当硝酸盐浓度为200 mg·L-1时,体系中的硝酸盐还原菌为假单胞菌和梭状芽胞杆菌;浓度增加至500 mg·L-1时,硝酸盐还原菌则是假单胞菌和热单胞菌.同时,甲烷转化率增加34.7%.研究结果为该菌群应用于含甲烷废气与含硝酸盐废水的协同处理提供科学依据.

Acclimatization and Community Structure Analysis of the Microbial Consortium in Nitrate-Dependent Anaerobic Methane Oxidation

Methane oxidation coupled with denitrification is an effective way to reduce the discharge of nitrate and methane. The anaerobic sludge from a laboratory wastewater treatment facility, anaerobic sludge from a wastewater treatment plant, and soil from a landfill were selected as inoculum to enrich the consortium for anaerobic methane oxidation in cooperation with nitrate reduction. The investigation of methane oxidation was carried out in these systems. The results showed that the maximum methane consumption rate of 0.05 mg·d^-1 was obtained when the anaerobic sludge from a wastewater treatment plant served as inoculum. The population of bacteria and archaea were assayed by the clone library method. The Methanosarcinales and Methanomicrobiales were present in methane oxidation as methane oxidizing archea. The Pseudomonas, Clostridia, and Thermomonas were identified as nitrate reducing bacteria in the process of nitrate reduction. Both the methane conversion rate and microbial population varied with the amount of nitrate. The nitrate reduction bacteria were Pseudomonas and Clostridia when the nitrate concentration was 200 mg·L^-1. The Pseudomonas and Thermomonas emerged when the nitrate concentration increased to 500 mg·L^-1, and the rate of methane conversion was increased by 34.7%. The results provided science evidence for the co-treatment of methane and nitrate.