METHANOL ACCUMULATION BY RESTING CELLS OF METHYLOSINUS TRICHOSPORIUM (I)

Techniques for measuring methanol accumulated by resting cells of Methylosinus trichosporium in the narrow range of 70-80mM phosphate concentration have been standardized. The maximum amount of methanol, 6μmol•mg-1•hr-1, was accumulated at a cell density of 2mg•ml-1 (w/v) of cells in the early stationary phase at pH 6.5, temperature 35°C. The phosphate-dependent inhibition of methanol dehydrogenase was found to be uncompetitive and reversible. Further, 80mM phosphate inhibited methane monooxygenase and formate dehydrogenase by 16% and 20% respectively. A possible biochemical explanation of the role of phosphate inhibition is offered.