Functional and genomic diversity of methylotrophic Rhodocyclaceae: description of Methyloversatilis discipulorum sp. nov.

<jats:p>Three strains of methylotrophic <jats:italic>Rhodocyclaceae</jats:italic> (FAM1<jats:sup>T</jats:sup>, RZ18-153 and RZ94) isolated from Lake Washington sediment samples were characterized. Based on phylogenetic analysis of 16S rRNA gene sequences the strains should be assigned to the genus <jats:italic>Methyloversatilis</jats:italic>. Similarly to other members of the family, the strains show broad metabolic capabilities and are able to utilize a number of organic acids, alcohols and aromatic compounds in addition to methanol and methylamine. The main fatty acids were 16:1ω7<jats:italic>c</jats:italic> (49–59 %) and 16:0 (32–29 %). Genomes of all isolates were sequenced, assembled and annotated in collaboration with the DOE Joint Genome Institute (JGI). Genome comparison revealed that the strains FAM1<jats:sup>T</jats:sup>, RZ18-153 and RZ94 are closely related to each other and almost equally distant from two previously described species of the genus <jats:italic>Methyloversatilis</jats:italic>, <jats:italic>Methyloversatilis universalis</jats:italic> and <jats:italic>Methyloversatilis thermotolerans</jats:italic>. Like other methylotrophic species of the genus <jats:italic>Methyloversatilis</jats:italic>, all three strains possess one-subunit PQQ-dependent ethanol/methanol dehydrogenase (Mdh-2), the <jats:italic>N</jats:italic>-methylglutamate pathway and the serine cycle (isocitrate lyase/malate synthase, Icl/ms<jats:sup>+</jats:sup> variant). Like <jats:italic>M. universalis</jats:italic>, strains FAM1<jats:sup>T</jats:sup>, RZ18-153 and RZ94 have a quinohemoprotein amine dehydrogenase, a tungsten-containing formaldehyde ferredoxin oxidoreductase, phenol hydroxylase, and the complete Calvin cycle. Similarly to <jats:italic>M. thermotolerans</jats:italic>, the three strains possess two-subunit methanol dehydrogenase (MxaFI), monoamine oxidase (MAO) and nitrogenase. Based on the phenotypic and genomic data, the strains FAM1<jats:sup>T</jats:sup>, RZ18-153 and RZ94 represent a novel species of the genus <jats:italic>Methyloversatilis</jats:italic>, for which the name <jats:italic>Methyloversatilis discipulorum</jats:italic> sp. nov. is proposed. The type strain is FAM1<jats:sup>T</jats:sup> ( = JCM 30542<jats:sup>T</jats:sup> = VKM = B-2888<jats:sup>T</jats:sup>).</jats:p>