Metabolic aspects of the growth of a pink-pigmented facultative methylotroph in carbon-limited chemostat culture

Summary The regulation of carbon metabolism in a pink-pigmented facultative methylotroph has been studied. In methanol-limited chemostat culture a pH optimum at 7.0 with a narrow growth rate optimum with respect to growth yield and metabolic uncoupling was revealed. The average growth yield was 14±0.036 g·mol^–1 and the organism displayed a low maintenance energy and high maximum specific growth rate. When the carbon concentration in the feed remained constant and the dilution rate increased a deviation from linearity between substrate consumption and growth rate was found at higher growth rates. The addition of a pulse of methanol to a carbon-limited culture showed that anabolism could be dissociated from catabolism with the resulting accumulation of formaldehyde in concentrations which were not lethal. Offprint requests to: F. M. Girio