Gibberellic acid production from Gibberella fujikuroi using agro-industrial residues

Abstract Gibberellic acid (GA3) was produced from Gibberella fujikuroi by solid-state fermentation (SSF) using a mixture of two agro-industrial wastes: rice bran and malt residue. The crude rice bran (CRB):malt residue (MR) proportion in the solid substrate, the moisture content, and the inorganic nitrogen amount were the parameters evaluated on the GA3 yield. After 7 days of cultivation, the highest GA3 yield was 934.41 mg/kg of substrate in optimum condition (65.95% of moisture, CRB:MR proportion (10:90 (wt.%)), and 1.60 g of inorganic nitrogen/kg of substrate). The best condition was used to determine the GA3 kinetic profile, being its maximum production of 1300 mg/kg of substrate after 10 days of fermentation. Therefore, the rice bran and malt residue mixture proved to be a promising substrate for the GA3 production by SSF.