title: Microbial population structure changes in a suspended carrier biofilm reactor.
abstract: The changes of microbial population structure in biofilm caused by variations of COD/NHNH4(+)-N ratio in influent were investigated in a suspended carrier biofilm reactor (SCBR). When COD/NHNH4(+)-N was 10, the highest COD removal reached was about 73.8 per cent, whereas the highest NH4(+)-N removal, about 55.9 per cent, was reached when COD/NH4(+)-N was 5. By using fluorescence in situ hybridization (FISH) and confocal laser scanning microscopy (CLSM) observation, it was found that the thickness of the biofilm formed on the carrier was about 80 to 120 microm, and ammonia-oxidizing bacteria (AOB) and nitrifying bacteria existed mainly in the upper layer about 20 to 30 microm. The results of the quinone profile analysis showed that when the COD/NH4(+)-N increased, the microbial diversity (DQ) increased, while the proportions of AOB and nitrifying bacteria in the biofilm communities decreased.
authors.affiliation: Pollution Control and Resource Reuse State Key Lab of China, Key Lab of Yangtze Aquatic Environment, Min. of Education of China, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China. wangrongchang@mail.tongji.edu.cn
authors.forename: R C
authors.initials: RC
authors.lastname: Wang
authors.forename: X H
authors.initials: XH
authors.lastname: Wen
authors.forename: Y
authors.initials: Y
authors.lastname: Qian
mesh_terms: D000641:Ammonia / Q000378:metabolism; D001419:Bacteria / Q000254:growth & development* / Q000302:isolation & purification; D018441:Biofilms; D019149:Bioreactors; D017404:In Situ Hybridization, Fluorescence; D018613:Microscopy, Confocal; D009566:Nitrates / Q000737:chemistry / Q000378:metabolism; D009584:Nitrogen / Q000378:metabolism; D010100:Oxygen / Q000378:metabolism; D011157:Population Dynamics; D014865:Waste Disposal, Fluid / Q000379:methods*; D014871:Water Microbiology
chemical_list: D009566:Nitrates; D000641:Ammonia; D009584:Nitrogen; D010100:Oxygen