title: GeoChip-based analysis of microbial community of a combined nitritation-anammox reactor treating anaerobic digestion supernatant.
abstract: A combined nitritation-anammox reactor was established to treat anaerobic digestion supernatant. The reactor achieved a nitrogen loading rate of 0.5 kg N/(m(3)·d) and total nitrogen removal efficiency of 85% after 140 days' operation. To examine the microbial community responsible for the process, GeoChip 4.0, a high-throughput, microarray-based metagenomic tool, was adopted to measure microbial functional potential under different percentages of digestion supernatant. Intriguingly, our results showed that microbial community composition in a stably functioning bioreactor were significantly different under varying environmental conditions. Functional gene diversities decreased with increasing percentages of digestion supernatant. Genes involved in organic remediation and metal resistance were highly abundant, revealing new metabolic potentials in addition to nitrogen and carbon removal. Compared to the significant decrease of genes involved in denitrification and nitrification caused by inhibition of the digestion supernatant, relative abundances of genes for anammox remained relatively stable. This could be partially attributed to the protection of biofilm, which was vital for the stable performance of nitrogen removal. In addition, nitrogen compounds, C/N ratio and the operation parameters (pH and temperature) were the key variables shaping the microbial community, contributing to a total of 76.64% of the variance of the reactor.
authors.affiliation: State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China.
authors.forename: Jian
authors.initials: J
authors.lastname: Zhao
authors.affiliation: State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China. Electronic address: jiane.zuo@tsinghua.edu.cn.
authors.forename: Jiane
authors.initials: J
authors.lastname: Zuo
authors.affiliation: State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China.
authors.forename: Xiaolu
authors.initials: X
authors.lastname: Wang
authors.affiliation: State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China.
authors.forename: Jia
authors.initials: J
authors.lastname: Lin
authors.affiliation: State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China.
authors.forename: Yunfeng
authors.initials: Y
authors.lastname: Yang
authors.affiliation: State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China; Institute for Environmental Genomics and Department of Botany and Microbiology, University of Oklahoma, Norman, OK 73019, USA.
authors.forename: Jizhong
authors.initials: J
authors.lastname: Zhou
authors.affiliation: State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China.
authors.forename: Houjuan
authors.initials: H
authors.lastname: Chu
authors.affiliation: State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China.
authors.forename: Peng
authors.initials: P
authors.lastname: Li
mesh_terms: D000641:Ammonia / Q000378:metabolism*; D001421:Bacteria, Anaerobic / Q000235:genetics*; D019149:Bioreactors / Q000382:microbiology*; D002244:Carbon / Q000032:analysis; D060833:Cellular Microenvironment; D005798:Genes, Bacterial / Q000235:genetics; D006863:Hydrogen-Ion Concentration; D064307:Microbiota / Q000235:genetics*; D009584:Nitrogen / Q000032:analysis; D020411:Oligonucleotide Array Sequence Analysis / Q000379:methods; D013045:Species Specificity; D013696:Temperature
chemical_list: D002244:Carbon; D000641:Ammonia; D009584:Nitrogen
keywords: Anaerobic digestion supernatant; Combined nitritation-anammox; GeoChip 4.0; Microbial community