Methylophilus glucosoxydans sp. nov., a restricted facultative methylotroph from rice rhizosphere

Abstract

Methylophilus glucosoxydans sp. nov., a restricted facultative methylotroph from rice rhizosphere Two restricted facultatively methylotrophic strains, designed B T and P, were isolated from rice roots. The isolates were strictly aerobic, Gram-negative, asporogenous, mesophilic, neutrophilic, motile rods that multiplied by binary fission and were able to synthesize indole-3-acetate. The cellular fatty acid profiles of the two strains were dominated by C 16 : 0 , C 16 : 1 v7c and C 16 : 0 2-OH. The major ubiquinone was Q-8. The predominant phospholipids were phosphatidylethanolamine and phosphatidylglycerol. Cardiolipin (diphosphatidylglycerol) was absent. The two strains assimilated methanol carbon at the level of formaldehyde via the ribulose monophosphate cycle (2-keto-3-deoxy-6-phosphogluconate variant). They lacked a-ketoglutarate dehydrogenase and glutamate dehydrogenase. They assimilated ammonium via the glutamate cycle enzymes glutamine synthetase and glutamate synthase. The DNA G+C contents of strains B T and P were 52.5 and 51.5 mol% (T m ), respectively. The level of DNA-DNA reassociation between these strains was 78 %, indicating that they belong to one species. Phylogenetic analysis of strain B T based on 16S rRNA and methanol dehydrogenase (mxaF) gene sequences showed a high level of similarity to members of the genus Methylophilus. As the two isolates were clearly distinct from all recognized members of the genus Methylophilus based on phenotypic data and levels of DNA-DNA relatedness (30-46 %), they are considered to represent a novel species, for which the name Methylophilus glucosoxydans sp. nov. is proposed; the type strain is B T (5VKM B-1607The genus Methylophilus comprises non-halophilic, obligately and restricted facultatively methylotrophic bacteria having the ribulose monophosphate ( The ability to grow on methanol is common to the type strains of these species. No NADP + -specific isocitrate dehydrogenase or glutamate dehydrogenase activities were observed for any Methylophilus species and diphosphatidylglycerol was absent from their phospholipid profile. However, these metabolic characteristics were not determined for M. rhizosphaerae CBMB127 T (Madhaiyan et al., 2009).We previously isolated two colourless restricted facultatively methylotrophic strains, designated B T and P, from the rhizosphere of rice (Oryza sativa L.) sampled from Vietnam (Doronina et al., 1988). Here, we describe the characterization of these strains, and show that they represent a single novel species of the genus Methylophilus. Strains BT and P were grown on 'medium K', containing (per litre): 2.0 g KH 2 PO 4 , 2.0 g (NH 4 ) 2 SO 4 , 0.025 g MgSO 4 . 7H 2 O, 0.5 g NaCl and 0.002 g FeSO 4 . 7H 2 O (pH 7.2). Solid medium K was prepared by adding 2.0 % (w/v) agar (Difco).

Methylobrevis pamukkalensis gen. nov., sp. nov., a halotolerant restricted facultative methylotroph isolated from saline water

“…Cellular fatty acids and polar lipids were analysed as described previously (Doronina et al , 2012).…”

Methylopila turkiensis sp. nov., a new aerobic facultatively methylotrophic phytosymbiont

“…The phospholipid composition of the cells was analyzed by two dimen sional thin layer chromatography [16].…”

Improved TNT detoxification by starch addition in a nitrogen-fixing Methylophilus-dominant aerobic microbial consortium

“…Thus, the aerobic TNT-degrading and nitrogen-fixing starch-utilizing bacteria in the MIK consortium may be a useful microbial resource for the bioremediation of nitrogen-deficient TNT-contaminated sites. The predominant population in the MIK consortium (Methylophilus) is an aerobic methanol-oxidizing rhizosphere bacterium [61,64] with capability to degrade a variety of nitrogen-containing contaminants, including methylamine, tetramethylammonium, and formamide [65]. Although, until now, Methylophilus has not been reported for explosive degradation, our findings suggest that Methylophilus could be a potential candidate for explosive detoxification in a nitrogen-deficient environment or rhizosphere.…”