Oricola thermophila sp. nov., a marine bacterium isolated from tidal flat sediment and emended description of the genus Oricola Hameed et al. 2015

Abstract

A Gram-stain-negative, facultatively anaerobic, rod-shaped (1.8-4.4×0.5-0.7 µm) and motile marine bacterium, designated as MEBiC13590T, was isolated from tidal flat sediment sampled at Incheon City, on the west coast of the Republic of Korea. The 16S rRNA gene sequence analysis revealed that strain MEBiC13590T showed high similarity to Oricola cellulosilytica CC-AMH-0T (98.2 %), followed by Oceaniradius stylonematis StC1T (97.5 %); however, it clustered with Oricola cellulosilytica. The phylogenomic tree inferred by the up-to-date bacterial core gene set suggested that strain MEBiC13590T shared a phyletic line with Oricola cellulosilytica. Average nucleotide identity and digital DNA-DNA hybridization values (75.0 and 19.3 %, respectively) between strain MEBiC13590T and Oricola cellulosilytica CC-AMH-0T were below the respective species delineation cutoffs. Growth was observed at 22-50 °C (optimum, 45 °C), at pH 5-9 (optimum, pH 7) and with 1-6 % (optimum, 3 %) NaCl. The predominant cellular fatty acids were C16 : 0 (7.6 %), C18 : 0 (12.2 %), 11-methyl C18 : 1 ω7c (5.7 %), C19 : 0 cyclo ω6c and summed feature 8 (comprising C18 : 1 ω7c and/or C18 : 1 ω6c; 38 %). The DNA G+C content was 63.5 mol%. The major respiratory quinone was Q-10. Several phenotypic characteristics such as growth temperature, oxygen requirement, enzyme activities of urease, gelatinase, lipase (C14), α-chymotrypsin, acid phosphatase, β-galactosidase, β-glucosidase etc. differentiate strain MEBiC13590T from Oricola cellulosilytica CC-AMH-0T. Based on this polyphasic taxonomic data, strain MEBiC13590T should be classified as representing a novel species in the genus Oricola for which the name Oricola thermophila sp. nov. is proposed . The type strain is MEBiC13590T (=KCCM 43313T=JCM 33661T).