PHYSIOLOGICAL AND CHEMOTAXONOMIC CHARACTERIZATION OF FILAMENTOUS BACTERIA BELONGING TO THE GENUS HALISCOMENOBACTER

Nine isolates of filamentous bacteria obtained from activated sludge a nd morphologically assigned to the genus Haliscomenobacter in addition to the type strain of Haliscomenobacter hydrossis DSM 1100(T) were st udied for cellular fatty acid composition, quinone type, physiological characteristics and protein profiles. Two selected representative str ains had the MK-7-menaquinone as the major quinone, and the MK-6-menaq uinone as minor component. The main components of cellular fatty acids in all strains were the 13-methyltetradecanoic acid (i15:0) followed by straight chain unsaturated acids of 16:1 and saturated acids of 16: 0 and 18:0. Hydroxylated fatty acids of 3-OH i15:0 and 2-OH i15:0 were found in higher amount in the type strain of H. hydrossis, whereas th e isolates from activated sludge produced these acids in minor amounts or traces. Analysis of physiological properties showed phenotypic hom ogeneity among the tested organisms. From 240 tested organic compounds , only few sugars (D-glucose, D-fructose and a few others) could be ut ilized as sole carbon source. Standardized protein profiles of the iso lates were very similar to the protein profile of H. hydrossis DSM 110 0(T). The results of the chemotaxonomic characterization are in line w ith the phylogenetic allocation of the genus Haliscomenobacter within the Saprospira subgroup of the flavobacter-bacteroides phylum.