title: Metabolism of methanol by Rhodopseudomonas acidophila.
abstract: Rhodopseudomonas acidophila strain 10050, grown anaerobically in the light on methanol, contained a methanol and formaldehyde dehydrogenase which could be coupled to phenazine methosulphate; an NAD-linked formaldehyde dehydrogenase which required GSH for activity; and an NAD-linked formate dehydrogenase. The specific activities of these enzymes varied in a non-coordinate manner when the organism was grown on different alcohols, formate or succinate. The affinity of the phenazine methosulphate linked methanol dehydrogenase for methanol was increased 10-fold if the cell-free extract was prepared and assayed in the absence of oxygen. Pulse-labelling experiments with [14C5methanol and [14C]bicarbonate indicated that fixation of carbon dioxide occurred via the ribulose diphosphate cycle and C3 + CO 2 fixation reaction(s). No evidence was obtained for operation of a reduced C1 fixation sequence. This conclusion was borne out by the enzyme content of cell-free extracts of the organism.
mesh_terms: D000429:Alcohol Oxidoreductases / Q000378:metabolism; D000445:Aldehyde Oxidoreductases / Q000378:metabolism; D000693:Anaerobiosis; D001639:Bicarbonates / Q000378:metabolism; D002474:Cell-Free System; D000431:Ethanol / Q000378:metabolism; D005557:Formaldehyde / Q000378:metabolism; D005561:Formates / Q000378:metabolism; D008027:Light; D000432:Methanol / Q000378:metabolism*; D010084:Oxidation-Reduction; D007652:Oxo-Acid-Lyases / Q000378:metabolism; D012241:Rhodopseudomonas / Q000201:enzymology / Q000378:metabolism*; D012273:Ribulose-Bisphosphate Carboxylase / Q000378:metabolism; D013386:Succinates / Q000378:metabolism
chemical_list: D001639:Bicarbonates; D005561:Formates; D013386:Succinates; D005557:Formaldehyde; D000431:Ethanol; D000429:Alcohol Oxidoreductases; D000445:Aldehyde Oxidoreductases; D012273:Ribulose-Bisphosphate Carboxylase; D007652:Oxo-Acid-Lyases; D000432:Methanol