Process optimization for the production of diosgenin with Trichoderma reesei

Area of Science:

• Biotechnology
• Microbial Fermentation
• Natural Product Chemistry

Background:

• Diosgenin is a valuable steroidal sapogenin precursor.
• Traditional diosgenin extraction methods, like acid hydrolysis, pose environmental concerns.
• Enzymatic pretreatment of Dioscorea zingiberensis offers a potential for improved diosgenin yield.

Purpose of the Study:

• To develop and optimize an effective microbial system for diosgenin production using Trichoderma reesei.
• To enhance diosgenin yield from enzymatically pretreated Dioscorea zingiberensis tubers.
• To compare the microbial method with traditional acid hydrolysis for environmental acceptability.

Main Methods:

• Response surface methodology (RSM) including Plackett-Burmann and central composite designs (CCD) were employed for optimization.
• Fermentation medium components (peptone, K(2)HPO(4), Tween 80) and conditions (pH, temperature, substrate concentration, incubation period) were optimized.
• Scale-up fermentation was performed in a 5.0 L bioreactor to validate the optimized process.

Main Results:

• Optimization of the fermentation medium and conditions led to a significant increase in diosgenin yield.
• The highest diosgenin yield achieved was 90.57% under optimized conditions (pH 5.8, 30°C, 6.5 days incubation).
• The optimized microbial process resulted in a 33.70% increase in yield compared to unoptimized conditions, with scale-up yielding 90.17% diosgenin.

Conclusions:

• The developed microbial system using Trichoderma reesei is highly effective for diosgenin production.
• The optimized process offers a cleaner and more environmentally acceptable alternative to conventional acid hydrolysis.
• This approach demonstrates the potential for sustainable production of diosgenin from plant sources.