Characteristics of microbial community functional structure of a biological coking wastewater treatment system
【摘要】：Nitrogenous heterocyclic compounds are key pollutants in coking wastewater; however, the functional potential of microbial communities for biodegradation of such contaminants during biological treatment is still elusive. Herein, a high throughput functional gene array(Geo Chip 5.0)in combination with Illumina Hi Seq2500 sequencing was used to compare and characterize the microbial community functional structure in a long run(500 days) bench scale bioreactor treating coking wastewater, with a control system treating synthetic wastewater. Despite the inhibitory toxic pollutants, Geo Chip 5.0 detected almost all key functional gene(average61,940 genes) categories in the coking wastewater sludge. With higher abundance, aromatic ring cleavage dioxygenase genes including multi ring1,2 diox; one ring2,3 diox; catechol represented significant functional potential for degradation of aromatic pollutants which was further confirmed by Illumina Hi Seq2500 analysis results. Response ratio analysis revealed that three nitrogenous compound degrading genes-nbz A(nitro-aromatics), tdn B(aniline), and scn ABC(thiocyanate) were unique for coking wastewater treatment, which might be strong cause to increase ammonia level during the aerobic process. Additionally, Hi Seq2500 elucidated carbozole and isoquinoline degradation genes in the system. These findings expanded our understanding on functional potential of microbial communities to remove organic nitrogenous pollutants;hence it will be useful in optimization strategies for biological treatment of coking wastewater.