title: Nitrogen removal properties in a continuous marine anammox bacteria reactor under rapid and extensive salinity changes.
abstract: Salinity tolerance is one of the most important factors for the application of bioreactors to high-salinity wastewater. Although marine anammox bacteria (MAB) might be expected to tolerate higher salinities than freshwater anammox bacteria, there is little information on the effects of salinity on MAB activity. This study aimed to reveal the nitrogen removal properties in a continuous MAB reactor under conditions of rapid and extensive salinity changes. The reactor demonstrated stable nitrogen removal performance with a removal efficiency of over 85% under salinity conditions ranging from 0 to 50 g/L NaCl. The reactor performance was also well maintained, even though the salinity was rapidly changed from 30 to 50 g/L and from 30 to 0 g/L. Other evidence suggested that the seawater medium used contained components essential for effective MAB performance. Bacterial community analysis using polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) showed that planctomycete UKU-1, the dominant MAB species in the inoculum, was the main contributor to anammox activity under all conditions. The PCR-DGGE using a universal bacterial primer set showed different DNA band patterns between the reactor biomass sample collected under conditions of 75 g/L NaCl and all other conditions (0, 30, 50 and freshwater-medium). All DNA sequences determined were very similar to those of bacterial species from marine environments, anaerobic environments, or wastewater-treatment facilities.
authors: Graduate School of Science and Technology, Kumamoto University, 2-39-1 Kurokami, Chuo-Ku, Kumamoto 860-8555, Japan.
authors: Qiaoyan
authors: Q
authors: Wei
authors: Graduate School of Science and Technology, Kumamoto University, 2-39-1 Kurokami, Chuo-Ku, Kumamoto 860-8555, Japan. Electronic address: qzt00564@nifty.ne.jp.
authors: Yasunori
authors: Y
authors: Kawagoshi
authors: Graduate School of Science and Technology, Kumamoto University, 2-39-1 Kurokami, Chuo-Ku, Kumamoto 860-8555, Japan.
authors: Xiaowu
authors: X
authors: Huang
authors: Graduate School of Science and Technology, Kumamoto University, 2-39-1 Kurokami, Chuo-Ku, Kumamoto 860-8555, Japan.
authors: Nian
authors: N
authors: Hong
authors: Graduate School of Science and Technology, Kumamoto University, 2-39-1 Kurokami, Chuo-Ku, Kumamoto 860-8555, Japan.
authors: Luong
authors: L
authors: Van Duc
authors: Graduate School of Science and Technology, Kumamoto University, 2-39-1 Kurokami, Chuo-Ku, Kumamoto 860-8555, Japan.
authors: Yuki
authors: Y
authors: Yamashita
authors: Graduate School of Science and Technology, Kumamoto University, 2-39-1 Kurokami, Chuo-Ku, Kumamoto 860-8555, Japan.
authors: Takehide
authors: T
authors: Hama
mesh_terms: D001419:Bacteria / Q000235:genetics / Q000378:metabolism; D019149:Bioreactors; D004269:DNA, Bacterial / Q000235:genetics; D058645:Denaturing Gradient Gel Electrophoresis; D058440:Denitrification; D005618:Fresh Water; D009584:Nitrogen / Q000378:metabolism*; D016133:Polymerase Chain Reaction; D054712:Salinity; D062065:Wastewater; D014874:Water Pollutants, Chemical / Q000378:metabolism*
chemical_list: D004269:DNA, Bacterial; D009584:Nitrogen; D062065:Wastewater; D014874:Water Pollutants, Chemical
keywords: Anammox; High-salinity tolerance; Marine anammox bacteria; Nitrogen removal performance; Reactor