Understanding of promoting enzymatic hydrolysis of combined hydrothermal and deep eutectic solvent pretreated poplars by Tween 80

In this study, lignin blockers including non-catalytic protein and surfactants were employed to promote enzy-matic digestibility of pretreated poplars. Among them, Tween 80 exhibited the most pronounced facilitation, improving the glucose yield from 26.6% to 99.6% at a low enzyme loading (10 FPU/g glucan), and readily reduced the required cellulase loading by 75%. The underlying mechanism for this remarkable improvement on glucose yields by Tween 80 was elucidated. The impacts of Tween 80 on the enzyme-lignin interaction were explored by quartz crystal microbalance analysis, revealing that the binding rate of Tween 80 on lignin surfaces was 3-fold higher than that of enzyme. More importantly, Tween 80 remarkably decreased the binding capacity and binding rate of enzyme on lignins. Furthermore, the substrate properties dominating the increase in glucose yields with Tween 80 were explored. The results facilitate to understand the underlying mechanism of the promotion of surfactants on enzymatic hydrolysis.

Automated summary

This study employed lignin blockers, including non-catalytic protein and surfactants, to enhance the enzymatic digestibility of pretreated poplars. Among them, Tween 80 showed the most significant improvement, increasing glucose yield and reducing the required enzyme loading. Quartz crystal microbalance analysis revealed that Tween 80 had a higher binding rate on lignin surfaces compared to enzymes and significantly reduced the enzyme-lignin binding capacity and rate. These findings contribute to understanding the mechanism of surfactant promotion in enzymatic hydrolysis.