Effects of pH and oxygen and ammonium concentrations on the community structure of nitrifying bacteria from wastewater

Article Abstract:

The impact of high ammonium concentrations, various pH values and different oxygen concentrations on nitrification and on community structure of nitrifying bacteria from wastewater was studied. Results showed that a high ammonium level resulted in a great community structure change that was reversible once the ammonium concentration was returned to its original level. The smaller changes in community structure brought about by the two pH extremes were irreversible.

Environmental aspects, Wetlands, Ammonium compounds, Ammonium salts

Nitrification and autotrophic nitrifying bacteria in a hydrocarbon-polluted soil

Article Abstract:

Research was conducted to examine the nitrification and autotrophic nitrifying bacteria in a hydrocarbon-polluted soil. The objective was to determine the effect of the addition of a hydrocarbon fuel on nitrification and nitrifying bacteria in an uncontaminated agricultural soil and in a soil with a long history of pollution. Results prove that nitrifying bacteria in polluted soil were characterized by a lower affinity for hydrocarbons.

Methods, Bioremediation, Hydrocarbons

Estimation of nitrifying bacterial activities by measuring oxygen uptake in the presence of the metabolic inhibitors allylthiourea and azide

Article Abstract:

A nitrifying biomass enriched and developed from activated sludge was used in the investigation of the selective inhibition of ammonia oxidation and nitrite oxidation by allylthiourea and azide respectively. The protocol is based on oxygen uptake using a batch type respirometer allowing bacterial activity differentiation in mixed cultures. Allylthiourea and azide were shown to be potent inhibitors of ammonia and nitrite oxidation.

Chemical inhibitors