Biomaterial Database

Development of nitrification inhibition assays using pure cultures of Nitrosomonas and Nitrobacter. 2001

C Grunditz, and G Dalhammar

Department of Biotechnology, Royal Institute of Technology (KTH), SE-100 44 Stockholm, Sweden.

Restricted requirements for nitrogen reduction at wastewater treatment plants have increased the need for assays determining the inhibition of nitrification. In this paper, two new assays studying ammonia oxidation and nitrite oxidation, respectively, are presented. As test organisms, pure cultures of Nitrosomonas and Nitrobacter isolated from activated sludge are used. The assays are performed in test tubes where the bacteria are incubated with the compound or wastewater to be tested. The nitrification rate is measured during 4 h and compared with reference samples. The test organisms were characterised with respect to temperature, pH and cell activity. Optimum temperature was 35 degrees C for Nitrosomonas and 38 degrees C for Nitrobacter; optimum pH was 8.1 for Nitrosomonas and 7.9 for Nitrobacter. There was a linear relationship between the nitrification rate and the cell concentration in the studied interval. The cell activity decreased slightly with storage time. A significant level of inhibition was calculated to 11% for the Nitrosomonas assay, and to 9% for the Nitrobacter assay. The assays are applicable to determination of nitrification inhibition in samples of industrial waste waters or influents of treatment plants, or chemical substances likely to be found in wastewater.

UI	MeSH Term	Description	Entries
D009573	Nitrites	Salts of nitrous acid or compounds containing the group NO2-. The inorganic nitrites of the type MNO2 (where M	Nitrite
D009576	Nitrobacter	A genus of gram-negative, rod-shaped bacteria that oxidizes nitrites to nitrates. Its organisms occur in aerobic environments where organic matter is being mineralized, including soil, fresh water, and sea water.
D009606	Nitrosomonas	A genus of gram-negative, ellipsoidal or rod-shaped bacteria whose major source of energy and reducing power is from the oxidation of ammonia to nitrite. Its species occur in soils, oceans, lakes, rivers, and sewage disposal systems.
D004269	DNA, Bacterial	Deoxyribonucleic acid that makes up the genetic material of bacteria.	Bacterial DNA
D004275	DNA, Ribosomal	DNA sequences encoding RIBOSOMAL RNA and the segments of DNA separating the individual ribosomal RNA genes, referred to as RIBOSOMAL SPACER DNA.	Ribosomal DNA,rDNA
D006863	Hydrogen-Ion Concentration	The normality of a solution with respect to HYDROGEN ions; H+. It is related to acidity measurements in most cases by pH	pH,Concentration, Hydrogen-Ion,Concentrations, Hydrogen-Ion,Hydrogen Ion Concentration,Hydrogen-Ion Concentrations
D000641	Ammonia	A colorless alkaline gas. It is formed in the body during decomposition of organic materials during a large number of metabolically important reactions. Note that the aqueous form of ammonia is referred to as AMMONIUM HYDROXIDE.
D013696	Temperature	The property of objects that determines the direction of heat flow when they are placed in direct thermal contact. The temperature is the energy of microscopic motions (vibrational and translational) of the particles of atoms.	Temperatures
D016133	Polymerase Chain Reaction	In vitro method for producing large amounts of specific DNA or RNA fragments of defined length and sequence from small amounts of short oligonucleotide flanking sequences (primers). The essential steps include thermal denaturation of the double-stranded target molecules, annealing of the primers to their complementary sequences, and extension of the annealed primers by enzymatic synthesis with DNA polymerase. The reaction is efficient, specific, and extremely sensitive. Uses for the reaction include disease diagnosis, detection of difficult-to-isolate pathogens, mutation analysis, genetic testing, DNA sequencing, and analyzing evolutionary relationships.	Anchored PCR,Inverse PCR,Nested PCR,PCR,Anchored Polymerase Chain Reaction,Inverse Polymerase Chain Reaction,Nested Polymerase Chain Reaction,PCR, Anchored,PCR, Inverse,PCR, Nested,Polymerase Chain Reactions,Reaction, Polymerase Chain,Reactions, Polymerase Chain
D017422	Sequence Analysis, DNA	A multistage process that includes cloning, physical mapping, subcloning, determination of the DNA SEQUENCE, and information analysis.	DNA Sequence Analysis,Sequence Determination, DNA,Analysis, DNA Sequence,DNA Sequence Determination,DNA Sequence Determinations,DNA Sequencing,Determination, DNA Sequence,Determinations, DNA Sequence,Sequence Determinations, DNA,Analyses, DNA Sequence,DNA Sequence Analyses,Sequence Analyses, DNA,Sequencing, DNA