sp. nov., a lanthanide-dependent methylotrophic bacteria isolated from rice field soil.

A new lanthanide (Ln)-dependent methanol-utilizing bacterial strain, La3113, was isolated from rice field soil and its taxonomic position was investigated using polyphasic approaches. The strain was aerobic, Gram-stain-negative, strongly motile, catalase-positive and cytochrome oxidase-positive. It could neither catalyse the hydrolysis of urea nor reduce nitrate to nitrite. Growth was observed within a temperature range of 10-40 °C and a pH range of 6-8, with optimum growth at 28 °C and pH 7. Methylamine was utilized as the single source of energy, carbon and nitrogen, and it was oxidized by methylamine dehydrogenase. C 7, C 6 and C were the dominant cellular fatty acids. Its draft genome (2.67 Mbp and 44.9 mol% G+C content) encodes genes including three Ln-dependent methanol dehydrogenase (XoxF-type MDH) genes, those for formaldehyde assimilation (ribulose monophosphate pathway), formate dehydrogenases and methylamine dehydrogenases, but not Ca-dependent MDH (MxaFI-MDH), which characterizes the species as a Ln-dependent methylotroph. The 16S rRNA gene sequence showed that strain La3113 belongs to the genus and is closely related to JLW8 (98.29 % identity). The digital DNA-DNA hybridization (dDDH) values (less than 30 %) and average nucleotide identity (ANI) values (less than 85 %) between genomes of strain La3113 and related type strains were lower than the thresholds for species delineation (70 % for dDDH and 95-96 % for ANI). On the basis of these polyphasic approaches, we propose a novel species, sp. nov. (type strain La3113=NBRC 111954=DSM 103219).