title: Optimum growth requirements of nitrifying consortia developed from treated sewage.
abstract: The optimum growth requirements of two nitrifying consortia developed from treated sewage by enrichment technique were determined by a series of experiments. There was total inhibition of nitrification at above 2.75 g l(-1) NH4(+)- N and 2.5 g l(-1) NO2(-)-N and the ammonia oxidizing consortium preferred a pH at 8.5 and the nitrite oxidizing consortium a pH of 7.5 as the optima for nitrification. Optimum temperatures were between 20 degrees and 30 degrees C for both the groups. As the rate of airflow was increased from 1 to 7 l/min, the build-up of NO2(-)-N increased 10-fold and the consumption of NO2(-)-N increased by a factor of 28.8 implying that the ammonia oxidizing consortium in a bioreactor required three times more aeration than that for nitrite oxidizers for expressing their full nitrifying potential. These data directly contribute for developing a fermentation process for the mass production of nitrifiers as well as for designing bioreactors for nitrifying sewage.
authors.affiliation: Environmental Microbiology Laboratory, School of Environmental Studies, Cochin University of Science and Technology, Fine Arts Avenue, Cochin 682 016, India.
authors.forename: Kavitha
authors.initials: K
authors.lastname: Ramachandran
authors.forename: I S Bright
authors.initials: IS
authors.lastname: Singh
mesh_terms: D000641:Ammonia / Q000737:chemistry; D019149:Bioreactors; D006863:Hydrogen-Ion Concentration; D009569:Nitric Oxide / Q000378:metabolism; D009573:Nitrites / Q000737:chemistry; D009584:Nitrogen / Q000737:chemistry*; D010100:Oxygen / Q000378:metabolism; D000644:Quaternary Ammonium Compounds / Q000737:chemistry; D012722:Sewage; D013696:Temperature; D014865:Waste Disposal, Fluid
chemical_list: D009573:Nitrites; D000644:Quaternary Ammonium Compounds; D012722:Sewage; D009569:Nitric Oxide; D000641:Ammonia; D009584:Nitrogen; D010100:Oxygen