Neptunitalea lumnitzerae sp. nov. isolated from the phyllosphere of the mangrove Lumnitzera racemosa Willd.

Abstract

A Gram-stain-negative, rod-shaped, non-motile, aerobic, light-yellow-pigmented bacterium, designated as strain Y10^T, was isolated from Lumnitzera racemosa leaf in Iriomote island mangrove forests in Japan. The 16S rRNA gene sequence analysis revealed that the isolate Y10^T was affiliated with the family Flavobacteriaceae, and the sequence showed the highest sequence identity to that of Neptunitalea chrysea NBRC 110019^T (97.2%) and others with below 96% sequence identity. The draft genome analysis revealed that its genomic size is 3.85 Mbp with G + C content 34.1%. The average nucleotide identity, average amino acid identity, and digital DNA–DNA hybridization values between strain Y10^T and Neptunitalea chrysea NBRC 110019^T was 79.07%, 76.35% and 19.6%, respectively, which were below the thresholds for prokaryotic species delineation (95–96%, 85%, and 70%, respectively). MK-6 was the only menaquinone, and the major cellular fatty acids (> 10% of the total fatty acids) were iso-C_15:0, iso-C_17:0 3-OH, and summed feature 3 (comprised of C_16:1ω7c-iso and C_15:0 2-OH). Based on its distinct phylogenetic position and genotypic and phenotypic characteristics, the strain represents a novel species of the genus Neptunitalea, for which the name Neptunitalea lumnitzerae sp. nov. is proposed. The type strain is Y10^T (= DSM 110280^T = NBRC 115783^T).