Muricauda amphidinii sp. nov., a novel marine bacterium isolated from the phycosphere of dinoflagellate Amphidinium carterae

A Gram-stain-negative, aerobic, rod-shaped and non-motile bacterium was isolated from a liquid culture of dinoflagellate Amphidinium carterae and further designated as LMIT004(T). Optimal growth was observed at 25 degrees C, pH 7.0 and in the presence of 2 % (w/v) NaCl. Oxidase and catalase were positive. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain LMIT004(T) showed high similarities to type strains Muricauda nanhaiensis SM17004(T) (96.77 %) and Muricauda aquimarina JCM11811(T) (95.60 %) but formed a separate branch in the genus Muricauda. The G+C content of strain LMIT004(T) was 39.0 mol%. The dominant fatty acids were iso-C-15.0 and iso-C-15.1 G. The polar lipids mainly contained phosphatidylethanolamine, five unidentified phospholipids and five unidentified polar lipids. The sole respiratory quinone was menaquinone-6 (MK-6). The draft genome of the type strain was 3.88 Mbp. The average nucleotide identity values between strain LMIT004(T) and the two reference strains M. nanhaiensis SM17004(T) and M. aquimarina JCM11811(T) were 77.47 and 73.49 %, respectively. Based on the polyphasic analysis, strain LMIT004(T) is suggested to represent a novel specie in the genus of Muricauda, for which the name Muricauda amphidinii sp. nov. is proposed. The type strain is LMIT004(T) (=CICC 24871(T)=KCTC 72948(T)).

Automated summary

The bacterium LMIT004(T) isolated from liquid culture of dinoflagellate Amphidinium carterae is a novel species in the genus Muricauda, showing Gram-stain-negative, aerobic, rod-shaped, and non-motile characteristics. It has high similarities with Muricauda nanhaiensis SM17004(T) and Muricauda aquimarina JCM11811(T) but forms a separate branch in phylogenetic analysis.