Dynamic of microbial community structure and interactions between functional bacteria based on the switch of trophic conditions in denitrifying sulfide removal process
Denitrifying sulfide removal (DSR) process was well-known by simultaneously converting nitrate,sulfide,and organic carbon into N2,S0,and CO2 through cooperation of autotrophic and heterotrophic denitrifiers.The species and interactions between functional bacteria were closely related to DSR performance.Figuring out the corresponding contribution of autotrophic and heterotrophic denitrifiers to the DSR performance was of great importance to its engineering application.In this study,the UASB bioreactor was started up in mixotrophic condition (M) with S∶N∶C=5∶6∶5,then operated under the switch of different trophic conditions.The total four switch stages for the DSR bioreactor was M=>A (autotrophic condition)=>H (heterotrophic condition)=>M.The removal rates of S2-,NO3-and Ac were 100 % during the whole operational period.S0 conversion rate in mixotrophic condition was up to 86%,whereas hardly any S2-was converted to S0 in autotrophic condition.Illumina sequencing with 16S rRNA identified that Thiobacillus and Thauera were the dominant denitrifiers with the percentage of 27.2% and 30.1% in stage A and stage H,respectively.In mixotrophic condition,heterotrophic denitrifiers (Azoarcus and Thauera) had the percentage of 34.1% in total,which was 80% of autotrophic denitrifier (Thiobacillus) in low loading rate (S2-=200mg/L).When inlfuent loading rate increased twice,Pseudomonas replaced Thauera as one of the dominent genera.The total percentage of Azoarcus and Pseudomonas was 30 and 40 times more than Thiobacillus in stage Ⅱ and V,respectively.Thus,we speculated there might be some heterotrophic denitrifiers,which can oxidize sulfide to drive denitrification (eg.Azoarcus taiwanensis sp.nov.and Pseudomonas sp.C27),primarily responsible for the removal capability in high loading rate instead of cooperation of autotrophic and heterotrophic denitrifiers in low loading rate in DSR process.
Microbial community trophic condition denitrifying sulfide removal,heterotrophic denitrifiers,autotrophic denitrifiers
Ruo-Chen Zhang Chuan Chen Xi-Jun Xu Xue-Ting Wang Nan-qi Ren
State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, 73 Huanghe Road, Harbin 150090, China
国际会议
The 15th IWA World Conference on Anaerobic Digestion( 第15届IWA世界厌氧大会)
北京
英文
541-544
2017-10-17（万方平台首次上网日期，不代表论文的发表时间）