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

A Gram-negative, strictly aerobic, rod-shaped, non-spore-forming bacterium, designated CAU 1555, 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 belonged to the genus Thauera and was closely related to Thauera hydrothermalis GD-2 (98.4% sequence similarity), Thauera lacus D20 (96.6%), and Thauera linaloolentis 47Lol (95.5%). Strain CAU 1555 possessed phosphatidylglycerol, diphosphatidylglycerol, phosphatidylethanolamine, one unidentified phospholipid, and one aminophospholipid as the major polar lipids; Q-8 as the predominant respiratory quinone; and C, summed feature 3 (comprising C1 and/or C), and summed feature 8 (comprising C/ C) 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 were 84.5%, 86.4%, and 28.0%, respectively. Whole-genome sequencing of strain CAU 1555 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 (= KCTC 72546 = MCCC 1K04065) as the type strain.