Submerged Fermentation of Orange Albedo to Produce Gibberellic Acid Using Fusarium moniliforme and Aspergillus niger

摘要

This study investigated the potential of orange albedo, an agro-industrial waste, as a suitable substrate for the production of gibberellic acid (GA) through submerged fermentation using Fusarium moniliforme ATCC 10052 and Aspergillus niger CBS 513.88 due to the high cost of synthetic and plant-extracted GA. The orange fruits were washed and the albedo removed. The albedo was dried, ground, and its proximate composition was determined. The ground orange albedo was incorporated into a modified CzapekDox medium and was fermented using the test fungi. Carboxymethyl cellulose (CMC) served as control. Fermentation conditions were: pH 5.5; inoculum size, 1 mL (5 x 105 CFU/mL F. moniliforme) (2 x 106 CFU/mL A. niger); substrate concentration 2 g; temperature 25±2 °C for seven days. Fermentation was optimized by supplementation with copper sulphate and variation of fermentation conditions. Results of proximate analysis were: moisture 7.46%; crude protein 4.69%; lipids 0.62%; ash 2.41%; crude fibre 27.67%; and carbohydrate 57.15%. GA yield by F. moniliforme and A. niger on the orange albedo substrate was 5.53 g/L and 6.33 g/L respectively. This increased to 9.39 g/L by F. moniliforme and 7.42 g/L by A. niger after optimization. These results support the suitability of orange albedo as a promising cheap substrate production of GA.