Formaldehyde Production by Cells of a Mutant of Candida boidinii S2 Grown in Methanol-limited Chemostat Culture

Formaldehyde production was investigated with cells of a mutant, AOU-1, of a methanol yeast, Candida boidinii S2 grown in methanol-limited chemostat culture. The highest productivity was shown with cells from the culture at a dilution rate of 0.075 hr^-1, when cells had the highest activity of alcohol oxidase and almost minimum activity of formaldehyde dehydrogenase. Under optimal reaction conditions, 950 mm formaldehyde was produced in 10-hr reaction with the cells. By the chemostat culture, not only formaldehyde productivity but also cell productivity was improved in comparison with batch culture. A maximum cell productivity of 0.2 g · liter^-1 · hr^-1 and a cell yield of 47% were obtained.