Pontibacter aquaedesilientis sp. nov., isolated from Jeongbang Waterfall, Jeju Island

Abstract

A red-pigmented, aerobic, motile by gliding, pleomorphic to long-rods and divided by budding bacterium, Gram-stain negative bacterium, designated JH31(T), was isolated from stream water of Jeongbang Waterfall, famous feature of Jeju Island, Republic of Korea. The cells grew at 9-40 degrees C (optimum, 28-30 degrees C), at pH 5.0-10.0 (pH 6.5-7.5) and with 0-6% NaCl (0% NaCl). Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain JH31(T) forms a lineage within the family Hymenobacteriaceae and clusters with its closest related species Pontibacter virorsus KCTC 42941(T) (98.1%), Pontibacter salisaro KACC 16885(T) (98.0%), Pontibacter amylolyticus JCM 19653(T) (97.2%), Pontibacter ramchanderi KACC 17384(T) (97.2%) and Pontibacter lucknowensis DM9(T) (96.4%). Strain JH31(T) produced carotenoid-type pigments but no flexirubin-type pigments. The genome was 4117105 bp long with 18 contigs and 3509 protein-coding genes. The DNA G+C content was 49.7 mol%. The digital DNA-DNA hybridization and average nucleotide identity values between the genome sequence of strain JH31(T) and its closely related reference strains were less than 19 and 72%, respectively. The draft genome of strain JH31(T) contained vital gene clusters involved in resistance against various metals, antibiotics, toxic compounds and radiation. The respiratory quinone of strain JH31(T) was menaquinone 7 and the predominant cellular fatty acids were iso-C-15:0, and summed feature 4 (comprising iso-C-17:1 I and/or anteiso B). The major polar lipids were phosphatidylethanolamine, three unidentified glycolipids, one unidentified phospholipid, one unidentified phosphoglycolipid and one unidentified aminoglycolipid. The phylogenetic, physiochemical and biochemical data showed that strain JH31(T) should represent a novel species in the genus Pontibacter, for which the name Pontibacter aquaedesilientis sp. nov. is proposed. The type strain for this novel species is JH31(T) (KACC 21705(T)=NBRC 114480(T)).