An aerobic, gliding, yellow-pigmented bacterium lacking flagella and showing strong tyrosinase activity, designated strain EM41(T), was isolated from seawater on the eastern coast of Jeju Island in Korea. Growth was observed at 15-35 degrees C (optimum, 25-30 degrees C) and at pH 6.5-9.0 (optimum, pH 7.0-8.5). Cells were Gram-negative, negative for flexirubin pigments and catalase- and oxidase-positive. The G+C content of the genomic DNA was 33.5 mol% and the major respiratory quinone was menaquinone-6 (MK-6). Comparative 16S rRNA gene sequence analysis showed that strain EM41(T) formed a distinct phyletic line within the genus Cellulophaga with a 100 % bootstrap value and was most closely related to Cellulophaga pacifica KMM 3664(T) (97.0 % sequence similarity). The level of DNA-DNA relatedness between strain EM41(T) and C. pacifica KMM 3664(T) was about 17.8 %. On the basis of phenotypic and genotypic data, strain EM41(T) is considered to represent a novel species of the genus Cellulophaga, for which the name Cellulophaga tyrosinoxydans sp. nov. is proposed. The type strain is EM41(T) (=KCTC 22297(T)=DSM 21164(T)).