THE INFLUENCE OF OXYGEN ON THE REDUCTION OF NITRITE BY WASHED SUSPENSIONS OF ADAPTED CELLS OF ACHROMOBACTER LIQUEFACIENS

Abstract

The influence of oxygen on the reduction of nitrate by adapted cells has been studied using a strain of Achromobacter liquejaciens which reduces nitrite but which does not reduce nitrate. The results have shown that active nitrite reduction occurs in the presence of oxygen and that the magnitude of the reduction is independent of the oxygen concentration in solution when the latter is a positive value. As the oxygen demand exceeds the supply however, the rate of nitrite reduction increases as the supply decreases.Nitrite exerts an inhibitory effect on the reduction of oxygen which, at low concentration, appears to be due purely to competition for electrons. At higher concentrations the inhibition appears to be directed towards the oxygen reducing enzymes.