Improving enzymatic hydrolysis of acid-pretreated bamboo residues using amphiphilic surfactant derived from dehydroabietic acid

• Published in: Bioresource technology 2019-12, Vol.293, p.122055-122055, Article 122055
• Main Authors: Lin, Wenqian, Chen, Dengfeng, Yong, Qiang, Huang, Caoxing, Huang, Shenlin
• Format: Article
• Language: English
• Subjects: Acid pretreatment; Amphiphilic surfactant; Bamboo; Enzymatic hydrolysis; Lignin adsorption site
• ISSN: 0960-8524; 1873-2976
• DOI: 10.1016/j.biortech.2019.122055

[Display omitted] •The hydrophobicity of lignin was reduced by pre-adsorbing surfactants.•Amphiphilic surfactant weaken adsorption between lignin and cellulase.•Reducing hydrophobicity of substrate promoted its enzymatic digestibility. In this work, amphiphilic surfactant was obtained using dehydroabietic acid from pine rosin and then pre-adsorbed with acid-pretreated bamboo residues (AP-BR) to block the residual lignin adsorption site, which is expected to improve its enzymatic digestibility. Results from cryogenic-transmission electron microscopy (Cryo-TEM) indicated amphiphilic surfactant with PEG with polymerization degree of 34 (D-34) aggregated to form worm-like micelles, which improved enzymatic hydrolysis yield of AP-BR from 24.3% to 71.9% by pre-adsorbing with 0.8 g/L. Amphiphilic surfactants pre-adsorbed on AP-BR could reduce hydrophobicity of AP-BR, adsorption affinity and adsorption capacity of lignin for cellulase from 0.51 L/g to 0.48–0.32 L/g, from 2.9 mL/mg to 1.8–1.4 mL/mg, and from 122.3 mg/g to 101.9–21.4 mg/g, respectively. These changed properties showed compelling positive contributions (R2 > 0.9) for free enzymes in the supernatants and sequently for final enzymatic hydrolysis yield, which was caused by blocking non-productively hydrophobic adsorption between lignin and cellulase.