Sustainable Sugar Syrup Production from Rice Husk Using Aspergillus niger Carbohydrase

Area of Science:

• Biotechnology
• Enzymology
• Biomass Conversion

Background:

• Cellulases are key enzymes for breaking down cellulose and converting lignocellulosic biomass.
• Cost-effective enzyme production is achievable via solid-state fermentation using inexpensive substrates.

Purpose of the Study:

• To optimize substrate composition and fermentation conditions for cellulase production.
• To characterize the enzymatic properties and application potential of the produced carbohydrase blend.

Main Methods:

• Simplex-Centroid and Doehlert designs were employed to optimize substrate mixture and fermentation parameters (temperature, moisture, time).
• Enzymatic activity, stability (pH, temperature, salt tolerance), and activation by ions/compounds were assessed.
• Hydrolysis of rice husk by the carbohydrase blend was analyzed using HPLC.

Main Results:

• Optimal substrate: 80% cocoa bean shell, 20% forage palm.
• Optimal fermentation: 28 °C, 60% moisture, 96 h.
• Enzymes showed broad pH activity, stability at 70 °C, halophilic properties (278% activity increase with NaCl), and activation by Ca2+ and DMSO.
• Carbohydrase blend hydrolyzed rice husk, yielding 13 mg reducing sugars/g biomass, with glucose and fructose identified.

Conclusions:

• The optimized enzymatic formulation demonstrates innovative biotechnological potential.
• The process is suitable for sustainable production of fructose-rich syrup from rice husk.
• The findings support applications in bioenergy generation and food waste valorization.