The Azotobacter flora of some Czechoslovakian watercourses

The occurrence of Azotobacter in some Szechoslovakian watercourses has been investigated. Several strains belonging to A. chroococcum and A. beijerinckii were isolated from 7 out of 18 samples. A. insignis has been isolated from the flowing water of Lake Machovo at Doksy. This is first report of this strictly aquatic Azotobacter species in Czechoslovakian watercourses. The taxonomy of the genus Azotobacter was discussed against the background of the existing knowledge resulting mainly from other taxonomic techniques than those based on the phenotypically expressed characters.