The effect of agitation speed, enzyme loading and substrate concentration on enzymatic hydrolysis of cellulose from brewer's spent grain

Author(s)

Mussatto, Solange I. ^{[1, 2]} ; Dragone, Giuliano ^[2] ; Fernandes, Marcela ^[2] ; Milagres, Adriane M. F. ^[2] ; Roberto, Ines C. ^[2]

Affiliation

^[1] Univ Minho, Dept Engn Biol, P-4710057 Braga - Portugal

^[2] Univ Sao Paulo, Dept Biotecnol, Escola Engn Lorena, Lorena, SP - Brazil

• Document type: Journal article
• Source: Cellulose; v. 15, n. 5, p. 711-721, 2008.
• Field of knowledge: Biological Sciences - Microbiology
• Web of Science Citations: 41

Abstract

Brewer’s spent grain components (cellulose, hemicellulose and lignin) were fractionated in a two-step chemical pretreatment process using dilute sulfuric acid and sodium hydroxide solutions. The cellulose pulp produced was hydrolyzed with a cellulolytic complex, Celluclast 1.5 L, at 45 °C to convert the cellulose into glucose. Several conditions were examined: agitation speed (100, 150 and 200 rpm), enzyme loading (5, 25 and 45 FPU/g substrate), and substrate concentration (2, 5 and 8% w/v), according to a 23 full factorial design aiming to maximize the glucose yield. The obtained results were interpreted by analysis of variance and response surface methodology. The optimal conditions for enzymatic hydrolysis of brewer’s spent grain were identified as 100 rpm, 45 FPU/g and 2% w/v substrate. Under these conditions, a glucose yield of 93.1% and a cellulose conversion (into glucose and cellobiose) of 99.4% was achieved. The easiness of glucose release from BSG makes this substrate a raw material with great potential to be used in bioconversion processes. (AU)

• FAPESP's process: 07/00993-9 - Production of enzymes and chelants by basidiomycetes and the relationship with the degradation of recalcitrant compounds
• Grantee: Adriane Maria Ferreira Milagres
• Support type: Regular Research Grants