Conversion of brewers' spent grain into proteinaceous animal feed using solid state fermentation

Area of Science:

• Biotechnology
• Agricultural Science
• Food Science

Background:

• Brewers' spent grain (BSG) is a major byproduct of beer production, with over 30 million tons generated globally each year.
• The valorization of BSG is crucial for reducing the environmental impact of the brewing industry and addressing the demand for sustainable animal feed.
• Current methods for BSG utilization often fall short of maximizing its nutritional potential for animal feed applications.

Purpose of the Study:

• To investigate the application of solid state fermentation (SSF) to improve the nutritional quality of brewers' spent grain (BSG).
• To evaluate the efficacy of Pleurotus ostreatus in enhancing the protein and beta-glucan content of BSG.
• To assess the potential of SSF-treated BSG as a high-value ingredient for animal feed.

Main Methods:

• Solid state fermentation (SSF) was employed using brewers' spent grain (BSG) as the substrate.
• The edible fungus Pleurotus ostreatus was utilized to initiate the SSF process.
• Key nutritional parameters, including protein content, beta-glucans, and cellulose, were analyzed before and after fermentation.

Main Results:

• The SSF process resulted in a significant 49.49% increase in the protein content of BSG.
• A remarkable 10-fold increase in 1,3-1,6 beta-glucans was observed after fermentation.
• Cellulose content was reduced by 11.42%, indicating improved digestibility.

Conclusions:

• Fungi-initiated SSF is a viable bioprocess for upgrading the nutritional profile of brewers' spent grain (BSG).
• Pleurotus ostreatus effectively enhances protein and beta-glucan levels in BSG, creating a more valuable animal feed.
• This approach offers a sustainable solution for managing brewing byproducts and producing nutrient-rich animal feed, addressing feed shortages.