Methylophaga alcalica sp. nov., a novel alkaliphilic and moderately halophilic, obligately methylotrophic bacterium from an East Mongolian saline soda lake.

A moderately haloalkaliphilic and obligately methylotrophic bacterium (strain M39T) with the ribulose monophosphate pathway of carbon assimilation is described. Cells of this methanol and methylamine utilizer are aerobic, Gram-negative, asporogenous, motile short rods, multiplying by binary fission. It is auxotrophic for vitamin B12 and requires NaHCO3 or NaCl for growth in alkaline medium. Its cellular fatty acid profile consists primarily of straight-chain saturated C16:0 and unsaturated C16:1 and C18:1 acids. The major ubiquinone is Q-8. The dominant phospholipids are phosphatidylethanolamine and phosphatidylglycerol. Diphosphatidylglycerol is also present. Optimal growth conditions are 25-29 degrees C, pH 9.0-9.5 and 3-4 % (w/v) NaCl. Cells accumulate the cyclic amino acid ectoine as the main compatible solute. The DNA G + C content is 48.3 mol%. Based on 16S rDNA sequence analysis and DNA-DNA relatedness (25-30 %) with the type strains of marine methylotrophs belonging to the genus Methylophaga, the novel isolate M39T (=VKM B-2251T =ATCC BAA-297T) was classified as the type strain of Methylophaga alcalica sp. nov.