INTERACTIONS AFFECTING GIBBERELLIC-ACID PRODUCTION IN SOLID-STATE CULTURE - A FACTORIAL STUDY

The production of GA3 in solid-state culture was studied using systems composed of maize cob particles soaked in an amylaceous effluent, as a function of three variables-particle diameter, volume of liquid phas e, and substrate concentration-with a determinant influence on the res ponse. The empirical model obtained provides an explanation of the beh avior of the system in terms of a series of interactions with underlyi ng problems of water activity and mass transfer, that can, however, be manipulated in a simple and reproducible manner. This model also allo ws the suitable orientation of production improvement, the interpretat ion of the mechanism of substrate inhibition detected, as well as mean s of correcting it without reducing the initial concentration of the s ubstrate, and leads to an 11-fold increase in the production obtained in the preliminary assays.