SOME CHEMOTAXONOMIC AND PHYSIOLOGICAL-PROPERTIES OF THE GENUS SPHAEROTILUS

Ten reference strains of the genus Sphaerotilus and five isolates of f ilamentous bacteria obtained from activated sludge and morphologically assigned to the genus Sphaerotilus were studied for cellular fatty ac id composition, quinone type, physiological characteristics and protei n profiles. All strains had the Q-8 ubiquinone as the major quinone. T he main components of cellular fatty acids in all strains were the str aight chain unsaturated acid 16:1 and saturated acid 16:0. All strains contained the hydroxylated fatty acid 3-OH 10:0, sometimes only in mi nor amounts or traces. Analysis of physiological properties showed phe notypic homogeneity among the tested organisms. From 240 tested organi c compounds, several sugars, organic acids and aromatic compounds coul d be utilized as sole carbon source. A clear differentiation from stra ins belonging to the morphological similar genus Leptothrix was possib le with several carbon source utilization tests. Standardized protein profiles of the isolates were also very similar indicating a high degr ee of homogeneity. The results of the chemotaxonomic characterization are in line with the phylogenetic allocation of the genus Sphaerotilus within the Rubrivivax subdivison of the beta subclass of the Proteoba cteria.