Effect of formaldehyde on kinetics of glucose consumption

The effect of formaldehyde on kinetics of biomass growth and consump­ tion of glucose by yeasts Candida tropicalis CC Y 29-7-33 has been inves­ tigated. For modelling of kinetics of biomass growth and consumption of the substrate the models according to Monod, Contois, and Andrews were applied. The parameters of kinetic equations were determined using the combined explicit and implicit Euler method. To determine the minimum of the chosen function the simplex method of determination of the minimum of a nonlinear function with several variables without limitations was uti­ lized. Of the models used to describe the kinetics of the process studied, the equation after Contois suited best. Comparable results were obtained also with the Monod's model. The results revealed the evident inhibitory effect of formaldehyde on growth of the biomass and consumption of the sub­ strate. Increase of formaldehyde concentration was accompanied by de­ crease of specific growth rate values and increase of saturation constant values.