Thauera sedimentorum sp. nov., Isolated from Coastal Sediment.

A Gram-negative, strictly aerobic, rod-shaped, non-spore-forming bacterium, designated CAU 1555 T , was isolated from a sediment sample collected on Jeju Island, Republic of Korea. Growth of the isolate was observed at 20-37 °C (optimum at 30 °C) and pH 5.5-10.0 (optimum at 8.0). Phylogenetic analysis based on the result of 16S rRNA gene sequences revealed that strain CAU 1555 T belonged to the genus Thauera and was closely related to Thauera hydrothermalis GD-2 T (98.4% sequence similarity), Thauera lacus D20 T (96.6%), and Thauera linaloolentis 47Lol T (95.5%). Strain CAU 1555 T possessed phosphatidylglycerol, diphosphatidylglycerol, phosphatidylethanolamine, one unidentified phospholipid, and one aminophospholipid as the major polar lipids; Q-8 as the predominant respiratory quinone; and C 16:0 , summed feature 3 (comprising C1 6:1ω6c and/or C 16:1ω7c ), and summed feature 8 (comprising C 18:1 ω7c / C 18:1 ω6c ) as the major fatty acids. The average nucleotide identity (ANI), average amino acid identity (AAI), and digital DNA-DNA hybridization (dDDH) values between the new isolate and T. hydrothermalis GD-2 T were 84.5%, 86.4%, and 28.0%, respectively. Whole-genome sequencing of strain CAU 1555 T revealed 3,955,289 bp with a DNA G + C content of 68.0 mol%. Based on the results of its polyphasic properties and genomic analysis, the isolate represents a novel species within the genus Thauera, for which the name Thauera sedimentorum sp. nov. is proposed, with CAU 1555 T (= KCTC 72546 T  = MCCC 1K04065 T ) as the type strain.