Tetrasphaera elongata sp. nov., a polyphosphate-accumulating bacterium isolated from activated sludge.

A new meso-diaminopimelic acid-containing, gram-positive bacterium was isolated from an activated sludge reactor showing enhanced biological phosphorus removal activity. The isolate was an asporogenous oval to rod-shaped bacterium, but occasionally formed clumps. The Neisser staining was positive, suggesting intracellular polyphosphate granules. The isolate was an aerobic chemoheterotroph which was capable of utilizing various sugars, sugar alcohols and organic acids. It contained anteiso-C15:0, iso-C15:0, iso-C14:0 and C16:0 as the major cellular fatty acids, and menaquinone-8(H4) as the major quinone. The G+C content of the genomic DNA was 69.6 mol%. Analysis of the 16S rDNA sequence revealed that the isolate is a new member of the family Intrasporangiaceae. The closest relatives were Tetrasphaera species. On the basis of the phenotypic and phylogenetic distinctiveness of the isolate, it was concluded that the organism represents a new species in the genus Tetrasphaera, for which the name Tetrasphaera elongata sp. nov. is proposed. The type strain is strain Lp2T (= JCM 11141T = DSM 14184T).