title: Protozoan predation on nitrification performance and microbial community during bioaugmentation.
abstract: The effects of predation on nitrification performance and microbial community during bioaugmentation were investigated. Although most of the nitrification ability of the seed source was lost in the seeded reactors, bioaugmentation significantly enhanced the activity and community of the nitrifiers. The ammonium uptake rate (AUR) increased from 2.59 to 15.25 mg NH4+-N/Lh and 2.88 to 13.36 mg NH4+-N/Lh, and the nitrite uptake rate (NUR) increased from 0.80 to 4.02 mg NO2--N/Lh and 0.76 to 4.34 mg NO2--N/Lh for the reactors with and without protozoa inhibition, respectively. The population of nitrifiers increased, and the dominant nitrite oxidizing bacteria (NOB) transferred from Nitrospira to Nitrobacter. Predation had an evident influence on the microbial community of nitrifiers, especially the K-strategist, which was more vulnerable to predation than r-strategist during bioaugmentation due to its low growth rate. However, predation did not have a significant effect on the nitrification performance.
authors: Key Lab of Water Resources, Environment and Ecology in Northwest China, Xi'an University of Architecture and Technology, Xi'an 710055, PR China. yulifang81@163.com
authors: Lifang
authors: L
authors: Yu
authors: Dangcong
authors: D
authors: Peng
authors: Yongxiang
authors: Y
authors: Ren
mesh_terms: D000641:Ammonia / Q000737:chemistry; D000818:Animals; D019149:Bioreactors; D001709:Biotechnology / Q000379:methods*; D002627:Chemistry, Physical / Q000379:methods; D017404:In Situ Hybridization, Fluorescence; D058465:Nitrification; D009576:Nitrobacter / Q000737:chemistry; D009584:Nitrogen / Q000737:chemistry; D010100:Oxygen / Q000737:chemistry; D000644:Quaternary Ammonium Compounds / Q000737:chemistry; D012722:Sewage / Q000382:microbiology*; D013997:Time Factors; D014865:Waste Disposal, Fluid / Q000379:methods; D014874:Water Pollutants, Chemical / Q000032:analysis; D018508:Water Purification / Q000379:methods
chemical_list: D000644:Quaternary Ammonium Compounds; D012722:Sewage; D014874:Water Pollutants, Chemical; D000641:Ammonia; D009584:Nitrogen; D010100:Oxygen