title: Characterization of Thauera-dominated hydrogen-oxidizing autotrophic denitrifying microbial communities by using high-throughput sequencing.
abstract: The present study, for the first time, reported a Thauera-dominated hydrogen-oxidizing autotrophic denitrifying microbial community enriched from different seed sludges including activated sludge and anaerobic digestion sludge. After 244 days enrichment, nitrogen removal rates reached up to 0.2 mg N/mg VSS/d which were comparable to that of the model organism Paracoccus denitrificans under the same conditions. Furthermore, high-throughput sequencing was applied to characterize and compare the seed sludges and enriched cultures. Operational taxonomic units (OTU)-based analysis (97% similarity cutoff) of total 280,000 16S rRNA gene V6 region sequences from 7 sludge samples (40,000 sequences per sample) revealed that the microbial diversity decreased after the enrichment, indicated by OTU numbers drop of 55-60%. Thauera species in the class of β-Proteobacteria were enriched into the dominant populations with relative abundances of 47-62%, regardless of seed sludge sources.
authors.affiliation: Environmental Biotechnology Laboratory, Department of Civil Engineering, The University of Hong Kong, Pokfulam Road, Hong Kong.
authors.forename: Yanping
authors.initials: Y
authors.lastname: Mao
authors.forename: Yu
authors.initials: Y
authors.lastname: Xia
authors.forename: Tong
authors.initials: T
authors.lastname: Zhang
mesh_terms: D001483:Base Sequence; D058440:Denitrification / Q000502:physiology; D006859:Hydrogen / Q000378:metabolism*; D059013:Microbial Consortia; D008969:Molecular Sequence Data; D009584:Nitrogen / Q000378:metabolism*; D010084:Oxidation-Reduction; D013045:Species Specificity; D020628:Thauera / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism*
chemical_list: D006859:Hydrogen; D009584:Nitrogen