Flavihumibacter profundi sp. nov., isolated from eutrophic freshwater sediment

A Gram-stain-positive, aerobic, non-motile, non-spore-forming, and rod-shaped bacterium, designated strain CHu64-6-1T, was isolated from a 67-cm-long sediment core collected from the Daechung Reservoir at a water depth of 17-m in Daejeon, Republic of Korea. Comparative 16S rRNA gene sequence studies placed the new isolate in the class Sphingobacteriia, and the isolate is notably most closely related to Flavihumibacter sediminis CJ663T (98.1% similarity), Flavihumibacter solisilvae 3-3T (97.8%), Flavihumibacter petaseus T41T (97.5%), Flavihumibacter cheonanensis WS16T (97.4%), and Flavihumibacter stibioxidans YS-17T (97.2%). The cells of strain CHu64-6-1T formed yellow colonies on R2A agar and contained MK-7 as the only menaquinone, phosphatidylethanolamine, an unidentified phospholipid, and two unidentified aminolipids as the major polar lipids, and C15:0 iso, C17:0 iso 3-OH, C15:1 iso G, and C16:1ω5c as the major fatty acids (> 5%). The DNA G + C content of the genome was determined to be 46.5 mol%. The DNA-DNA hybridization values of strain CHu64-6-1T with F. sediminis CJ663T, F. solisilvae 3-3T, F. petaseus T41T, F. cheonanensis WS16T, and F. stibioxidans YS-17T were 12.4–33.2%. Based on the combined genotypic and phenotypic data, we propose that strain CHu64-6-1T represents a novel species of the genus Flavihumibacter, for which the name Flavihumibacter profundi sp. nov. is proposed. The type strain is CHu64-6-1T (= KCTC 62290T = CCTCC AB 2018060T).