A novel approach to the biorefinery of brewery spent grain

Author(s)

Outeirino, David ^[1] ; Costa-Trigo, Ivan ^[1] ; de Souza Oliveira, Ricardo Pinheiro ^[2] ; Perez Guerra, Nelson ^[3] ; Manuel Dominguez, Jose ^[1]

Affiliation

^[1] Univ Vigo, Ind Biotechnol & Environm Engn Croup BiotecnIA, Campus Ourense, As Lagoas S-N, Orense 32004 - Spain

^[2] Univ Sao Paulo, Biochem & Pharmaceut Technol Dept, Fac Pharmaceut, Av Prof Lineu Presses 580, B1 16, BR-05508900 Sao Paulo - Brazil

^[3] Univ Vigo, Fac Sci, Dept Analyt & Food Chem, Campus Ourense, As Lagoas S-N, Orense 32004 - Spain

• Document type: Journal article
• Source: Process Biochemistry; v. 85, p. 135-142, OCT 2019.
• Web of Science Citations: 1

Abstract

This article describes a new three-step biorefinery process for the complete fractionation of brewery spent grain (BSG). First, BSG was assessed as a substrate for the production of enzymatic cocktails, mainly xylanases, through solid-state fermentation with Aspergillus brasiliensis. Second, the spent solid residue (SSR) recovered was delignified with cholinium glycinate ionic liquid, reducing the Klason lignin by 75.26% and the soluble lignin by 62.92%. In addition, scanning electron microscopy of the carbohydrate-rich material (CRM) showed some microfibrils and pores, which facilitated the diffusion of enzymes. Third, an enzymatic hydrolysis of the CRM was assayed with Aspergillus extracts and commercial enzyme preparations, such as Ultraflo L (R), to release fermentable sugars under non-optimized conditions. Preliminary results showed that Ultraflo L (R) and Aspergillus extract have similar yields in the hydrolysis of glucans and xylans in BSG. No xylose, and only low amounts of glucose, were released from the SSR. Meanwhile, an improvement of the enzymatic hydrolysis in CRM was noted through the increase in saccharification of all fractions, this reaching xylan at 54.37% when Aspergillus extract was used. Although more experimental research is needed to optimize the enzymatic hydrolysis, these results illustrate the clear benefits of the integrated process proposed. (AU)

• FAPESP's process: 18/04563-3 - Biotechnological production of antimicrobial compounds of interest to the pharmaceutical, veterinary and food industries
• Grantee: Ricardo Pinheiro de Souza Oliveira
• Support Opportunities: Research Grants - Visiting Researcher Grant - International