Gibberellic Acid Production by Fusarium moniliforme and Aspergillus niger Using Submerged Fermentation of Banana Peel

Abstract

The present study aimed to produce gibberellic acid through fermentation using banana (Musa sapientum) peel waste as substrate. Banana peel, a domestic and industrial waste, constitutes a potential source of cheap fermentable substrate for the production of other value-added products. Fusarium moniliforme ATCC 10052 and Aspergillus niger CBS 513.88 were used as fermenting organisms. The substrate was dried, ground and its proximate composition determined. The powdered substrate was added to a modified CzapekDox broth (a semisynthetic medium), with Carboxyl methylcellulose (CMC) as control. The fermentation conditions were: pH 5.5; inoculum size 1% (5 × 105 spores/mL F. moniliforme) (2 × 106 spores/mL A. niger); substrate concentration 2 g; temperature 25 ± 2 oC; fermentation time 7 days. The fermentation was optimized by varying pH, inoculum size, substrate concentration and fermentation time. The extracted GA was subjected to infra-red spectroscopy using FT-IR. The parameters which gave the highest GA yields were thereafter combined in a single fermentation. The results of proximate analysis of banana peel substrate revealed 8.65% moisture, 9.54% protein, 5.40% lipids, 11.45% ash, 22.34% crude fibre, and 42.62% carbohydrate. The GA yields of 13.55 g/L and 12.44 g/L were produced from the banana peel substrate and 3.62 and 2.61 g/L from the CMC control by F. moniliforme and A. niger respectively. Under optimized conditions, F. moniliforme produced 17.48 g/L GA, while A. niger produced 13.50 g/L. Extracted GA was similar to standard GA sample and the present results support the potential use of banana peel for fermentative GA production.

Keywords

• Aspergillus niger
• banana peel
• fermentation
• Fusarium moniliforme
• gibberellic acid