title: Improved method for determination of ammonia and nitrite oxidation activities in mixed bacterial cultures.
abstract: A simple and reliable method to measure the activity of ammonia and nitrite oxidisers in mixed bacterial cultures was developed. The developed method differentiates between the ammonia and nitrite oxidisers by consecutive injection of NO2- and NH4+. The main advantage of this method is that it avoids the use of metabolic inhibitors for ammonia or nitrite oxidisers, as used by other methods. Moreover, it allows measuring of the short-term effect of an inhibitor on both the ammonia and nitrite oxidisers in one test under controlled environmental conditions (pH, temperature). The developed method was applied to determine the inhibitory effects of salt (NaCl up to 15 g Cl/l) on an enriched culture of nitrifying bacteria. The results of the method demonstrate its potential to accurately determine the individual activities of nitrite and ammonia oxidisers.
authors.affiliation: UNESCO-IHE Institute for Water Education, P.O. Box 3015, 2601 DA Delft, The Netherlands.
authors.forename: M S
authors.initials: MS
authors.lastname: Moussa
authors.forename: H J
authors.initials: HJ
authors.lastname: Lubberding
authors.forename: C M
authors.initials: CM
authors.lastname: Hooijmans
authors.forename: M C M
authors.initials: MC
authors.lastname: van Loosdrecht
authors.forename: H J
authors.initials: HJ
authors.lastname: Gijzen
mesh_terms: D000641:Ammonia / Q000378:metabolism*; D001419:Bacteria / Q000254:growth & development / Q000378:metabolism*; D001431:Bacteriological Techniques; D019149:Bioreactors; D002254:Carbonates / Q000494:pharmacology; D003470:Culture Media / Q000737:chemistry; D009573:Nitrites / Q000378:metabolism*; D009585:Nitrogen Dioxide / Q000378:metabolism; D010084:Oxidation-Reduction; D000644:Quaternary Ammonium Compounds / Q000378:metabolism; D012722:Sewage / Q000382:microbiology*; D012965:Sodium Chloride / Q000494:pharmacology
chemical_list: D002254:Carbonates; D003470:Culture Media; D009573:Nitrites; D000644:Quaternary Ammonium Compounds; D012722:Sewage; D012965:Sodium Chloride; C005686:sodium carbonate; D000641:Ammonia; D009585:Nitrogen Dioxide