The effects of limiting nutrients, dilution rate, culture pH, and temperature on the yield constant and anthocyanin accumulation of carrot cells grown in semicontinuous chemostat cultures

Abstract

With carrot cells grown in semicontinuous culture with phosphate as limiting nutrient. Dougall and Weyrauch (1980) found that the steady-state culture density was different at different dilution rates. They suggested that the yield constant for biomass was different at different dilution rates. Here the yield constant for biomass for PO(4) (3-), NH(4) (+), Mg(2+), and glucose-limited semicontinuous cultures has been measured directly at two dilution rates. The yield constants for PO(4) (3-), NH(4) (+), and Mg(2+) but not for glucose are different at the two dilution rates. The effects of pH and temperature on the biomass yield constant was measured to extend the number of system parameters examined. Biomass yield constant was changed little with change from 25 to 28 degrees C or from pH 4.2 to pH 5.5. The steady-state levels of anthocyanin were also measured. The responses of anthocyanin levels to the system parameters are different to the biomass responses. The data suggest that at different values of each of the system parameters, the composition and metabolic activities of the cells at steady state in semicontinuous cultures are different.