Flavobacterium croceum sp. nov., isolated from activated sludge.

A Gram-negative, non-motile, rod-shaped bacterium, designated strain EMB47(T), was isolated from activated sludge performing enhanced biological phosphorus removal in a sequencing batch reactor. Growth was observed between 10 and 40 degrees C (optimum, 25-35 degrees C) and between pH 5.0 and 8.5 (optimum, pH 7.5-8.0). The predominant fatty acids of strain EMB47(T) were iso-C(16 : 0) 3-OH, iso-C(15 : 1) G, C(15 : 0), iso-C(15 : 0), iso-C(14 : 0) and iso-C(16 : 0) and it contained phosphatidylethanolamine, diphosphatidylglycerol and phosphatidylcholine as polar lipids. The G+C content of the genomic DNA was 40.8 mol% and the major quinone was MK-6. Comparative 16S rRNA gene sequence analyses showed that strain EMB47(T) formed a distinct phyletic line within the genus Flavobacterium. The levels of 16S rRNA gene sequence similarity with respect to Flavobacterium species were below 94.7 %. On the basis of the phenotypic, chemotaxonomic and molecular data, strain EMB47(T) represents a novel species within the genus Flavobacterium, for which the name Flavobacterium croceum sp. nov. is proposed. The type strain is EMB47(T) (=KCTC 12611(T)=DSM 17960(T)).