Effect of salinity on the activity of nitrifying bacteria. In：L.M. Chou et al. (ed.)

Abstract

The ammonia-N uptake rate of nitrifying bacteria in a culture medium not only varies from one genera of bacteria to another but also from one salinity to another. In this study, a non-marine genera of nitrifying bacteria was isolated from the activated sludge of a night-soil treatment plant and acclimated before its use. The specific aoi.monia-N uptake rate (q) of the nitrifying bacteria acclimated to salinity of 20 ppt (SI) and 33 ppt (S3) was respectively determined. In addition, the q values of the acclimated nitrifying bacteria of Si, under shock loading of the increase of salinity from S1 to S2 (25 ppt) and S3 were determined. The q values of the acclimated nitrifying bacteria of S3, under shock loading of the decrease of salinity from S3 to S2 and Si, were also determined. The results showed that the q values of the acclimated nitrifying bacteria of Si were greater than that of S2. In addition, the q values of the acclimated nitrifying bacteria of both SI and S3 decreased with increasing salinity when they were cultured under a shock loading of salinity environment.