Glucoamylase production by solid-state fermentation using rice flake manufacturing waste products as substrate

Area of Science:

• Biotechnology
• Enzymology
• Microbial Fermentation

Background:

• Agro-industrial wastes are abundant and underutilized resources.
• Glucoamylase is a key enzyme in starch hydrolysis.
• Solid-state fermentation (SSF) offers an eco-friendly approach for enzyme production.

Purpose of the Study:

• To investigate glucoamylase production using various agro-industrial wastes.
• To optimize SSF conditions for enhanced enzyme yield.
• To evaluate the impact of nutrient supplementation on enzyme production.

Main Methods:

• Solid-state fermentation of paddy processing wastes (coarse, medium, fine), wheat bran, and rice powder using Aspergillus sp. HA-2.
• Optimization of inoculum concentration, temperature, and pH.
• Supplementation with carbon (sucrose, glucose) and nitrogen (yeast extract, peptone) sources.
• Determination of optimal temperature and pH for enzyme activity.

Main Results:

• Wheat bran yielded the highest glucoamylase (264 U/gds), followed by coarse (211.5 U/gds) and medium waste (192.1 U/gds).
• Supplementation with sucrose/glucose and organic nitrogen sources significantly increased enzyme production.
• Optimal enzyme activity was observed at 55°C and pH 5, enhanced by calcium ions.

Conclusions:

• Agro-industrial wastes, particularly wheat bran, are suitable substrates for glucoamylase production via SSF.
• Nutrient supplementation and controlled fermentation conditions are crucial for maximizing enzyme yield.
• The findings support the use of microbial fermentation for valorizing agro-industrial byproducts into valuable enzymes.