Growth characteristics of Candida utilis on volatile substrate in a multistage tower fermentor.

The influence of increasing ethanol concentration in the feed on growth and physiological activity of the yeast Candida utlis was studied. The measurements were made at steady states of continuous culture under constant values of dilution rate, temperature, and pH in all stages of the fermentor; Synthetic ethanol was used as the sole source of carbon and energy in the concentration range 10-100 g/liter. The maximum biomass concentration in the effluent and maximum productivity was achieved at 75 g ethanol/liter in the feed. In respect to ethanol losses in the outlet and biomass yield, the optimum ethanol concentration in the input of the growth medium was found to be about 50 g/liter using a four-stage system.