title: Pyrosequencing analysis of microbial communities in hollow fiber-membrane biofilm reactors system for treating high-strength nitrogen wastewater.
abstract: Wastewaters from swine farms, nitrogen-dealing industries or side-stream processes of a wastewater treatment plant (e.g., anaerobic digesters, sludge thickening processes, etc.) are characterized by low C/N ratios and not easily treatable. In this study, a hollow fiber-membrane biofilm reactors (HF-MBfR) system consisting of an O2-based HF-MBfR and an H2-based HF-MBfR was applied for treating high-strength wastewater. The reactors were continuously operated with low supply of O2 and H2 and without any supply of organic carbon for 250 d. Gradual increase of ammonium and nitrate concentration in the influent showed stable and high nitrogen removal efficiency, and the maximum ammonium and nitrate removal rates were 0.48 kg NH4(+)-N m(-3) d(-1) and 0.55 kg NO3(-)-N m(-3) d(-1), respectively. The analysis of the microbial communities using pyrosequencing analysis indicated that Nitrosospira multiformis, ammonium-oxidizing bacteria, and Nitrobacter winogradskyi and Nitrobacter vulgaris, nitrite-oxidizing bacteria were highly enriched in the O2-based HF-MBfR. In the H2-based HF-MBfR, hydrogenotrophic denitrifying bacteria belonging to the family of Thiobacillus and Comamonadaceae were initially dominant, but were replaced to heterotrophic denitrifiers belonging to Rhodocyclaceae and Rhodobacteraceae utilizing by-products induced from autotrophic denitrifying bacteria. The pyrosequencing analysis of microbial communities indicates that the autotrophic HF-MBfRs system well developed autotrophic nitrifying and denitrifying bacteria within a relatively short period to accomplish almost complete nitrogen removal.
authors.affiliation: Department of Chemical Engineering, Hanyang University, 222 Wangshimni-Ro, Seongdong-Ku, Seoul 04763, South Korea.
authors.forename: Jung-Hun
authors.initials: JH
authors.lastname: Park
authors.affiliation: The Research Institute of Industrial Science, Hanyang University, 222 Wangshimni-Ro, Seongdong-Ku, Seoul 04763, South Korea.
authors.forename: Okkyoung
authors.initials: O
authors.lastname: Choi
authors.affiliation: The Research Institute of Industrial Science, Hanyang University, 222 Wangshimni-Ro, Seongdong-Ku, Seoul 04763, South Korea.
authors.forename: Tae-Ho
authors.initials: TH
authors.lastname: Lee
authors.affiliation: Department of Environmental Engineering, University of Seoul, 163 Seoulsiripdae-ro, Dongdaemun-Ku, Seoul 02504, South Korea. Electronic address: h_kim@uos.ac.kr.
authors.forename: Hyunook
authors.initials: H
authors.lastname: Kim
authors.affiliation: Department of Chemical Engineering, Hanyang University, 222 Wangshimni-Ro, Seongdong-Ku, Seoul 04763, South Korea. Electronic address: biosang@hanyang.ac.kr.
authors.forename: Byoung-In
authors.initials: BI
authors.lastname: Sang
mesh_terms: D064751:Ammonium Compounds / Q000378:metabolism*; D000818:Animals; D052818:Autotrophic Processes; D001419:Bacteria / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification* / Q000378:metabolism; D018441:Biofilms; D019149:Bioreactors / Q000382:microbiology*; D058440:Denitrification; D059014:High-Throughput Nucleotide Sequencing; D009566:Nitrates / Q000378:metabolism*; D058465:Nitrification; D012722:Sewage / Q000382:microbiology; D013552:Swine; D062065:Wastewater / Q000382:microbiology*
chemical_list: D064751:Ammonium Compounds; D009566:Nitrates; D012722:Sewage; D062065:Wastewater
keywords: Denitrification; Hollow fiber-membrane biofilm reactor; Microbial community; Nitrification; Pyrosequencing analysis