Lutimonas zeaxanthinifaciens sp. nov. , a zeaxanthin-producing marine bacterium isolated from coastal sediment

Abstract

A Gram-stain-negative, yellow-pigmented, strictly aerobic, non-flagellated, motile by gliding, rod-shaped bacterium, designated strain YSD2104^T, was isolated from a coastal sediment sample collected from the southeastern part of the Yellow Sea. Phylogenetic analysis based on the 16S rRNA gene sequences revealed that strain YSD2104^T was closely related to three type strains, Lutimonas vermicola IMCC1616^T (97.4 %), Lutimonas saemankumensis SMK-142^T (96.9 %), and Lutimonas halocynthiae RSS3-C1^T (96.8 %). Strain YSD2104^T has a single circular chromosome of 3.54 Mbp with a DNA G+C content of 38.3 mol%. The average nucleotide identity and digital DNA-DNA hybridization values between strain YSD2104^T and the three type strains (L. vermicola IMCC1616 ^T, L. saemankumensis SMK-142^T, and L. halocynthiae RSS3-C1^T) were 74.0, 86.2 and 73.6 %, and 17.9, 30.3 and 17.8 %, respectively. Growth was observed at 20-30 °C (optimum, 30 °C), at pH 6.5-8.5 (optimum, pH 7.0), and with NaCl concentrations of 1.5-3.5 % (optimum, 2.5 %). The major carotenoid was zeaxanthin, and flexirubin-type pigment was not produced. The major respiratory quinone was menaquinone-6. The major fatty acids (>10 %) were iso-C_{15 : 0}, iso-C_{15 : 1} G, iso-C_{17 : 0} 3-OH, summed feature 3 (C_{16 : 1} ω6c and/or C_{16 : 1} ω7c), and summed feature 9 (iso-C_{17 : 1} ω9c and/or 10-methyl C_{16 : 0}). The major polar lipids were phosphatidylethanolamine, one unidentified aminophospholipid, two unidentified aminolipids, and eight unidentified lipids. Conclusively, based on this polyphasic approach, we classified strain YSD2104^T (=KCTC 102008^T=JCM 36287^T) as representing a novel species of the genus Lutimonas and proposed the name Lutimonas zeaxanthinifaciens sp. nov.

Keywords: Flavobacteriaceae; Lutimonas; coastal sediment; zeaxanthin-producing.