# Optimized GA3 Production by Aspergillus niger and Fusarium fujikuroi: From Low-Cost Fermentation to Agronomic Application

## TL;DR

This study optimized low-cost fermentation for gibberellic acid (GA3) production using two fungi and showed improved crop yield in common beans.

## Contribution

A cost-effective method for GA3 production using Aspergillus niger and its successful agronomic application in common beans.

## Key findings

- A. niger produced 597.03 mg/L of GA3, the highest among the tested fungi.
- GA3 application increased common bean yield to 44.8 bags per hectare.
- GA3 reduced antioxidant enzyme activity in treated plants.

## Abstract

This study aimed to optimize low-cost submerged fermentation
for
gibberellic acid (GA3) production using Aspergillus niger LGB-034–2015 and Fusarium fujikuroi Insumicro 175, followed by evaluating
the fermentation supernatant in common bean (Phaseolus
vulgaris) under field conditions. A factorial design
and central composite design were applied to test different concentrations
of glucose (10–30 g/L), glycerol (5–15 g/L), and yeast
extract (2–6 g/L). Maximum GA3 production reached
597.03 mg/L (0.60 g/L) for A. niger and 487.23 mg/L (0.49 g/L) for F. fujikuroi. The highest yield per unit of substrate consumed was 550 mg of
GA3 per gram of glucose by A. niger. In
the agronomic trials, the supernatant was applied as a foliar spray
at 200 mL per plot (four applications during the crop cycle) and compared
with untreated controls. The results showed a significant reduction
in activity of antioxidant enzymes, such as superoxide dismutase (SOD),
catalase (CAT), and peroxidase (POD), and an increase in yield, reaching
44.8 bags per hectare. These findings demonstrate that optimizing
GA3 fermentation with A. niger is a cost-effective approach with practical applications in crop
productivity.