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Colwellia agarivorans sp. nov., an agar-digesting marine bacterium isolated from coastal seawater

Xu, Zhen-Xing, Zhang, Heng-Xi, Han, Ji-Ru, Dunlap, Christopher A., Rooney, Alejandro P., Mu, Da-Shuai, Du, Zong-Jun
International journal of systematic and evolutionary microbiology 2017 v.67 no.6 pp. 1969-1974
Colwellia, Gram-negative bacteria, anaerobes, aquaculture, aquatic bacteria, coastal water, fatty acids, flagellum, new species, nucleotide sequences, pH, phenotype, phosphatidylethanolamines, phylogeny, ribosomal DNA, sequence homology, sodium chloride, ubiquinones, China
A novel Gram-stain-negative, facultatively anaerobic, yellowish and agar-digesting marine bacterium, designated strain QM50**T, was isolated from coastal seawater in an aquaculture site near Qingdao, China. Phylogenetic analysis based on 16S rDNA sequences revealed that the novel isolate represented a member of the genus Colwellia and exhibited the highest sequence similarity (97.0 %) to the strain Colwellia aestuarii SMK-10**T. Cells of strain QM50**T are approximately 0.3–0.6 × 0.8–2.5 µm in size and motile by means of a polar flagellum. Growth occurs in the presence of 1.0–6.0 % (w/v) NaCl (optimum, 2.0–3.0 %), at pH 6.5–8.5 (optimum, 7.0) and at 4–37°C (optimally, 28–30 °C). Strain QM50**T was found to contain ubiquinone 8 (Q-8) as the predominant ubiquinone and summed feature 3 (C16:1 omega7c and/or iso-C 15:0 2-OH), C16:0 and C17:1 omega8c as main cellular fatty acids. Phosphatidylethanolamine and an unidentified lipid were found to be major polar lipids. The DNA G+C content of strain QM50**T was determined to be 35.7 mol%. On the basis of phylogenetic and phenotypic data, strain QM50**T represents a novel species of genus Colwellia, for which the name Colwellia agarovorans sp. nov. is proposed. The type strain is QM50**T (= KCTC 52273**T = MCCC 1H00143**T).