Methyloversatilis thermotolerans sp. nov., a novel thermotolerant facultative methylotroph isolated from a hot spring

Abstract

A newly isolated facultatively methylotrophic bacterium (strain 3t(T)) was investigated. Cells of the isolate were Gram-stain-negative, asporogenous, non-motile rods that multiplied by binary fission. The strain utilized methanol, methylamine and a variety of multicarbon compounds as carbon and energy sources. Growth occurred at pH 6.5-8.5 (optimally at 7.0-7.5) and at 10-45 °C (optimally at 30-37 °C). The major fatty acids of methanol-grown cells were C16 : 1ω7c and C16 : 0. The predominant phospholipids were phosphatidylethanolamine and phosphatidylglycerol. The major ubiquinone was Q-8. Strain 3t(T) possessed pyrroloquinoline quinone (PQQ)-linked methanol dehydrogenase and assimilated C1 units at the level of formaldehyde and CO2 via the serine cycle. The DNA G+C content of the strain was 63.6 mol% (Tm). On the basis of 16S rRNA gene sequence similarity (98.1 %) and rather low DNA-DNA relatedness (30 %) with the type strain of the type species of the genus Methyloversatilis (Methyloversatilis universalis FAM5(T)), and physiological and biochemical characteristics, the isolate was classified as a representative of a new species of the genus and named Methyloversatilis thermotolerans 3t(T) ( = VKM B-2692(T) = CCUG 61694(T) = DSM 25156(T)).