Diversity of isolates of Acinetobacter from activated sludge systems based on their whole cell protein patterns

Whole cell protein extracts from strains of the currently recognized genomic species of Acinetobacter, together with those from a range of isolates of several genomic species identified using the Biolog system and obtained from a biological nutrient-removal activated sludge plant were analysed by SDS-PAGE. The dendrograms obtained after numerical analysis for the known genomic species generally supported the taxonomic relationships suggested from earlier DNA–DNA hybridisation data. In some cases the activated sludge isolates identified to genomic species level clustered closely with the corresponding genomic species reference strains, although isolates 5 and 8/9 were scattered throughout the dendrogram. Considerable variations were seen in the protein patterns of the 27 different environmental isolates of genomic species 7 that were analysed. Three unidentified Acinetobacter isolates examined formed their own subcluster.