Hymenobacter siberiensis sp. nov., isolated from a marine sediment of the East Siberian Sea and Hymenobacter psoromatis sp. nov., isolated from an Antarctic lichen

Abstract

Gram-staining-negative, strictly aerobic, red-pink-colored, rod-shaped, and non-motile bacterial strains, PAMC 29290, PAMC 29294T and PAMC 29296 were isolated from marine surface sediments of the East Siberian Sea and PAMC 26553 and PAMC 26554T were obtained from an Antarctic lichen, Psoroma antarcticum. Phylogenetic and phylogenomic analyses revealed that strains PAMC 29290, PAMC 29294T, PAMC 29296, PAMC 26553 and PAMC 26554T belong to the genus Hymenobacter. Strains PAMC 29290, PAMC 29294T and PAMC 29296 were closely related with Hymenobacter artigasi (98.8% 16S rRNA gene similarity), Hymenobacter antarcticus (97.3%) and Hymenobacter glaciei (96.9%) and PAMC 26553 and PAMC 26554T showed high similarity with Hymenobacter ginsengisoli (97.0%), Hymenobacter rivuli (96.1%) and Hymenobacter setariae (95.9%). Genomic relatedness analyses showed that strains PAMC 29290, PAMC 29294T and PAMC 29296 are distinguished from H. artigasi with average nucleotide identity (ANI) values (93.1？93.2%) and digital DNA-DNA hybridization (dDDH) values (50.3？51.0%). PAMC 26553 and PAMC 26554T are clearly distinguished from H. ginsengisoli with ANI values (< 79.8%) and dDDH values (< 23.3%). The major fatty acids of strains PAMC 29290, PAMC 29294T and PAMC 29296 were C15:0 iso (21.0？26.0%), summed feature 3 (C16:1 ω7c and/or C16:1 ω6c; 17.4？18.2%), C15:0 anteiso (12.7？19.1%), and summed feature 4 (C17:1 iso I and/or anteiso B; 8.6？16.1%) and those of strains PAMC 26553 and PAMC 26554T were summed feature 3 (C16:1 ω7c and/or C16:1 ω6c; 20.7？22.2%), C15:0 anteiso (17.5？19.7%), and summed feature 4 (C17:1 iso I and/or anteiso B; 15.5？18.1%). The major respiratory quinone was MK-7. The genomic DNA G+C contents were 60.6？60.8%. The polar lipids of PAMC 29294T were found to consist of phosphatidylethanolamine, four unidentified aminolipids, an unidentified aminophospholipid, and five unidentified lipids and those of PAMC 26554T were phosphatidylethanolamine, three unidentified aminolipids, four unidentified aminophospholipid, and two unidentified lipids. The distinct phylogenetic position and some physiological characteristics distinguished strains PAMC 29290, PAMC 29294T, PAMC 29296, PAMC 26553 and PAMC 26554T from other species in the genus Hymenobacter. Based on the phylogenetic, biochemical, and chemotaxonomic analyses, two novel species are proposed as Hymenobacter siberiensis sp. nov. (type strain, PAMC 29294T = KCTC 82466T = JCM 34574T) and Hymenobacter psoromatis PAMC 26554T sp. nov. (type strain, PAMC 26554T = KCTC 82464T = JCM 34572T) respectively.