Optimization of Ganoderma lucidum Polysaccharides Fermentation Process for Large-Scale Production.

Area of Science:

• Biotechnology
• Mycology
• Biochemistry

Background:

• Ganoderma lucidum is known for producing bioactive polysaccharides.
• Optimizing fermentation conditions is crucial for maximizing yields of intracellular polysaccharides.

Purpose of the Study:

• To enhance the intracellular polysaccharide yield of Ganoderma lucidum.
• To determine the molecular weight distribution and mass fraction of intracellular and extracellular polysaccharides.
• To evaluate the feasibility of large-scale production.

Main Methods:

• Central composite design was used to optimize the fermentation medium.
• Shake flask experiments and large-scale fermentors (5-L and 50-L) were employed.
• High-performanceSEC-multi-angle laser scattering-refractive index (HPSEC-MALLS-RI) was used for molecular weight analysis.

Main Results:

• Optimized medium (glucose 40 g/L, yeast powder 12 g/L, KH2PO4 3 g/L, pH 5.5, inoculum 10 mL/100 mL) predicted 2.03 g/L yield.
• Shake flask yield reached 1.98 g/L; fermentor yields were 2.59 g/L (5-L) and 2.65 g/L (50-L).
• Intracellular polysaccharide component 1: Mw 4.695 × 10^6 Da (58% mass fraction). Extracellular polysaccharide component 2: Mw 5.554 × 10^4 Da (94.9% mass fraction).

Conclusions:

• The optimized liquid submerged fermentation process significantly increased Ganoderma lucidum intracellular polysaccharide yield.
• The produced intracellular and extracellular polysaccharides exhibit good immunological activity.
• The optimized process is suitable for large-scale industrial production.