FIG. 2.

Optical densities at 660 nm (O.D.660 nm) (●) and concentrations of glucose (○), ethanol (□), and glycerol (■) in anaerobic, pH-controlled batch cultures of C. utilis (A), Z. bailii (B), and S. cerevisiae (C). Cultures were grown at pH 3.0 on a synthetic medium (22) containing Tween 80 and ergosterol and supplemented with 20 g of glucose per liter. Fermentors were sparged with nitrogen gas to minimize oxygen diffusion into the cultures. Data from two independent replicate experiments differed by less than 10%.