Distribution of autotrophic nitrifying bacteria in a polluted river (the Passaic)

Abstract

The abundance of nitrifying bacteria, determined by most-probable-number procedures within habitats of the Passaic River was as follows: rooted aquatic plants > algae =∞ rocks > sediments >> water. On the average, NH4+ oxidizers were 540-fold more abundant in the topmist 1 cm of sediment than in the water, and NO2- oxidizers were 250-fold more abundant. The population densities in this surface sediment at two nearby stations, one with a predominantly mineral stream bed andthe other an organic ooze, did not differ significantly. Large numbers of nitrifiers were present to a depth of about 5 cm in a mineral sediment core.