Effects of Non-Ionic Surfactant Tween 80 on Enzymatic Saccharification of Avicel and Steam-Exploded Poplar at High Solid Loading

Surfactants demonstrate considerable potential in enzymatic saccharification at high solids loading (ESHSL). In this paper, the effects of the non-ionic surfactant Tween 80 on enzymatic saccharification of Avicel and steam-exploded poplar (SEP) at high solid loading were studied. The results showed that under the fed-batch conditions of 15.0% solid loading, 20 FPU/g glucan, and 1.0% Tween 80, the maximum enzymatic saccharification rate of Avicel and SEP achieved was 65.4% (128.2 g/L glucose) and 86.4% (93.9 g/L glucose), respectively. Moreover, Tween 80 improved the rheological properties of ESHSL slurry of SEP, especially for the fed-batch model, reducing the complex viscosity, shear stress, and storage modulus. Furthermore, cellulase adsorption assays, SDS-PAGE, Rose Bengal staining, and Zeta potential analysis demonstrated that Tween 80 reduced non-productive adsorption of cellulase (particularly β-glucosidase) on lignin through hydrophobic interactions. All these findings contribute to establishing a foundation for subsequent investigative efforts within the discipline.