title: Effect of pretreatment and enzymatic hydrolysis of wheat straw on cell wall composition, hydrophobicity and cellulase adsorption.
abstract: The present study aimed to determine the impact of cell wall composition and lignin content on enzyme adsorption and degradability. Thioacidolysis analysis of residual lignins in wheat straw after steam-explosion or organosolv pretreatment revealed an increase in lignin condensation degree of 27% and 33%, respectively. Surface hydrophobicity assessed through wettability tests decreased after the pretreatments (contact angle decrease of 20-50%), but increased with enzymatic conversion (30% maximum contact angle increase) and correlatively to lignin content. Adsorption of the three major cellulases Cel7A, Cel6A and Cel7B from Trichoderma reesei decreased with increasing hydrolysis time, down to 7%, 31% and 70% on the sample with the highest lignin content, respectively. The fraction of unspecifically bound enzymes was dependent both on the enzyme and the lignin content. Adsorption and specific activity were shown to be inversely proportional to lignin content and hydrophobicity, suggesting that lignin is one of the factors restricting enzymatic hydrolysis.
authors: IFP Energies nouvelles, 1 et 4, avenue de Bois-Préau, 92852 Rueil-Malmaison, France. Senta.BLANQUET@ifpenergiesnouvelles.fr
authors: Senta
authors: S
authors: Heiss-Blanquet
authors: Dan
authors: D
authors: Zheng
authors: Nicolas
authors: N
authors: Lopes Ferreira
authors: Catherine
authors: C
authors: Lapierre
authors: Stéphanie
authors: S
authors: Baumberger
mesh_terms: D000327:Adsorption; D002473:Cell Wall / Q000737:chemistry*; D002480:Cellulase / Q000737:chemistry*; D002482:Cellulose / Q000737:chemistry; D006868:Hydrolysis; D013499:Surface Properties; D014242:Trichoderma / Q000201:enzymology; D014908:Triticum; D017155:Wettability
chemical_list: D002482:Cellulose; D002480:Cellulase