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 °C (optimum, 25-35 °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).