Methylopila musalis sp. nov., an aerobic, facultatively methylotrophic bacterium isolated from banana fruit

Abstract

A newly isolated, facultatively methylotrophic bacterium (strain MUSAT) was investigated. The isolate was strictly aerobic, Gram-stain-negative, asporogenous, motile, rod-shaped and multiplied by binary fission. The strain utilized methanol, methylamine and an apparently narrow range of multi-carbon compounds, but not methane, dichloromethane or CO2/H2, as the carbon and energy sources. Growth occurred at pH 5.5–9.5 (optimum, pH 7.0) and 16–40 °C (optimum, 28–30 °C). The major fatty acids of methanol-grown cells were C18 : 1ω7c, C18 : 0and 11-methyl-C18 : 1ω7c. The predominant phospholipids were phosphatidylethanolamine, phosphatidylcholine, phosphatidylglycerol and phosphatidylmonomethylethanolamine. The major ubiquinone was Q-10. The strain had methanol and methylamine dehydrogenases as well as the enzymes of theN-methylglutamate pathway (lyases of γ-glutamylmethylamide andN-methylglutamate). C1assimilation occurs via the isocitrate lyase-negative serine pathway. Ammonium was assimilated by glutamate dehydrogenase and the glutamate cycle (glutamate synthase/glutamine synthetase). The DNA G+C content of the strain was 64.5 mol% (determined from the melting temperature). Based on 16S rRNA gene sequence similarity (97.0–98.9 %) and DNA–DNA relatedness (36–38 %) with representatives of the genusMethylopila(Methylopila capsulataIM1TandMethylopila jiangsuensisJZL-4T) the isolate was classified as a novel species of the genusMethylopila, for which the nameMethylopila musalissp. nov. is proposed. The type strain is MUSAT( = VKM B-2646T = DSM 24986T = CCUG 61696T).