Hyunsoonleella zeaxanthinifaciens sp. nov., Isolated from Coastal Seawater of Jeju Island, Republic of Korea

Abstract

A Gram-stain-negative, strictly aerobic, yellow-pigmented, non-motile, rod-shaped rod-shaped bacterium, designated J2K-J805T, was isolated from coastal seawater of Jeju Island, Republic of Korea. Strain J2K-J805T grew at 15–37°C (optimum, 30°C), pH 6.0–8.0 (optimum, pH 7.0–7.5) and in the presence of 1–4% (w/v) NaCl (optimum, 2–3%) and was catalase-positive and oxidase-negative. The strain showed the highest 16S rRNA gene sequence similarity to Hyunsoonleella flava T58T (98.4%). Phylogenetic and phylogenomic analyses based on the 16S rRNA gene and whole-genome sequences placed strain J2K-J805T within the genus Hyunsoonleella as a distinct lineage. The OrthoANIu and digital DNA-DNA hybridization values between strain J2K-J805T and H. flava T58T were 87.7 and 34.5%, respectively, both below their respective thresholds for species delineation. The genome size and DNA G+C content were 3,825,400 bp and 34.9 mol%, respectively. The predominant respiratory quinone was MK-6, and the major cellular fatty acids were iso-C15:1 G, iso-C15:0 and iso-C17:0 3-OH. The polar lipid profile comprised phosphatidylethanolamine, three unidentified aminolipids, two unidentified glycolipids and five unidentified lipids. High-performance liquid chromatography with photodiode-array detection identified the major yellow pigment as zeaxanthin, and the genome contained the carotenoid biosynthesis genes crtB, crtI, crtY and crtZ together with genes for isoprenoid precursor supply. On the basis of these polyphasic data, strain J2K-J805T represents a novel species, for which the name Hyunsoonleella zeaxanthinifaciens sp. nov. is proposed. The type strain is J2K-J805T (= KCTC 102498T = JCM 38469T).