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

A Gram-negative, strictly aerobic, rod-shaped, non-spore-forming bacterium, designated CAU 1555T, 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 1555T belonged to the genus Thauera and was closely related to Thauera hydrothermalis GD-2T (98.4% sequence similarity), Thauera lacus D20T (96.6%), and Thauera linaloolentis 47LolT (95.5%). Strain CAU 1555T possessed phosphatidylglycerol, diphosphatidylglycerol, phosphatidylethanolamine, one unidentified phospholipid, and one aminophospholipid as the major polar lipids; Q-8 as the predominant respiratory quinone; and C16:0, summed feature 3 (comprising C16:1ω6c and/or C16:1ω7c), and summed feature 8 (comprising C18:1 ω7c/ C18:1 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-2T were 84.5%, 86.4%, and 28.0%, respectively. Whole-genome sequencing of strain CAU 1555T 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 1555T (= KCTC 72546T = MCCC 1K04065T) as the type strain.