Some Aspects of Gibberella fujikuroi Culture Concerning Gibberellic Acid Production

Abstract

Gibberellic acid (GA 3 ) is a plant growth regulator produced by Gibberella fujikuroi in submerged fermentation. Studies concerning the effects of several carbon and nitrogen sources on GA 3 production were carried out. Sucrose-starch mixture was found to be the best carbon source. No significant differences between the nitrogen sources tested were observedTwo methods were compared for estimating {\textmu} of Gibberella fujikuroi grown in different proportions of glucose and starch. The specific growth rate of Gibberella fujikuroi estimated by an image processing technique (measuring tip extension and mean hyphal length in a Petri dish) was in close agreement with measurements performed in a stirred fermentor. In addition, submerged culture was found to be better than solid-state culture for the strain under study. 1 vvm and 700 rpm were found to be the conditions leading to the highest GA 3 production. Application of cell-free, HPLC characterized fermented broth in cuban ``Tangor Ortanique ''orchard resulted in a yield increase.