Gibberellic Acid Production by Different Fermentation Systems Using Citric Pulp as Substrate/Support.

Area of Science:

• Biotechnology and Bioengineering
• Plant Science and Agricultural Chemistry

Background:

• Gibberellic acid (GA3), a key plant hormone regulating growth, is crucial for agricultural and biotechnological applications.
• Fusarium moniliforme and Gibberella fujikuroi are known producers of GA3, but optimizing production remains a focus.
• Utilizing agro-industrial byproducts like citric pulp offers a sustainable approach to microbial fermentation.

Purpose of the Study:

• To evaluate and compare GA3 production by Fusarium moniliforme LPB03 and Gibberella fujikuroi LPB06.
• To assess the efficacy of different fermentation techniques: solid-state fermentation (SSF), submerged fermentation (SmF), and semisolid state fermentation (SSSF).
• To investigate the influence of various bioreactor types on GA3 yield using citric pulp as a substrate.

Main Methods:

• Microbial cultivation of Fusarium moniliforme and Gibberella fujikuroi using citric pulp as substrate/support.
• Implementation of SSF in Erlenmeyer flasks and column bioreactors.
• Execution of SmF in Erlenmeyer flasks, stirred tank reactors (STR), and bubble column reactors (BCR).
• Conducting SSSF using citric pulp suspension in Erlenmeyer flasks and BCR.

Main Results:

• SSF achieved high GA3 yields of 7.60 g/kg in Erlenmeyer flasks and 7.34 g/kg in column bioreactors.
• SmF yielded up to 273.00 mg/L in a 10 L STR, while SSSF reached 331.00 mg/L in Erlenmeyer flasks.
• All tested methods demonstrated cost-effectiveness and produced substantial GA3 quantities.

Conclusions:

• Fermentation technique selection significantly impacts GA3 productivity.
• Solid-state fermentation and semisolid state fermentation using citric pulp are promising, cost-effective methods for GA3 production.
• The evaluated processes are suitable for industrial applications requiring gibberellic acid.