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Background: Cellulase adsorbed on cellulose is productive and helpful to produce reducing sugars in enzymatic hydrolysis of lignocellulose; however, cellulase adsorbed on lignin is non-productive. Increasing productive adsorption of cellulase on cellulose would be beneficial in improving enzymatic hydrolysis. Adding lignin that was more hydrophilic in hydrolysis system could increase productive adsorption and promote hydrolysis. However, the effect mechanism is still worth exploring further. In this study, lignosulfonate (LS), a type of hydrophilic lignin, was used to study its effect on cellulosic hydrolysis. Results: The effect of LS on the enzymatic hydrolysis of pure cellulose (Avicel) and lignocellulose [dilute acid (DA) treated sugarcane bagasse (SCB)] was investigated by analyzing enzymatic hydrolysis efficiency, productive and non-productive cellulase adsorptions, zeta potential and particle size distribution of substrates. The result showed that after adding LS, the productive cellulase adsorption on Avicel reduced. Adding LS to Avicel suspension could form the Avicel–LS complexes. The particles were charged more negatively and the average particle size was smaller than Avicel before adding LS. In addition, adding LS to cellulase solution formed the LS–cellulase complexes. For DA-SCB, adding LS decreased the non-productive cellulase adsorption on DA-SCB from 3.92 to 2.99 mg/g lignin and increased the productive adsorption of cellulase on DA-SCB from 2.00 to 3.44 mg/g cellulose. Besides, the addition of LS promoted the formation of LS–lignin complexes and LS–cellulase complexes, and the complexes had more negative charges and smaller average sizes than DA-SCB lignin and cellulase particles before adding LS. Conclusions: In this study, LS inhibited Avicel's hydrolysis, but enhanced DA-SCB's hydrolysis. This stemmed from the fact that LS could bind cellulase and Avicel, and occupied the binding sites of cellulase and Avicel. Thus, a decreased productive adsorption of cellulase on Avicel arose. Regarding DA-SCB, adding LS, which enhanced hydrolysis efficiency of DA-SCB, increased the electrostatic repulsion between DA-SCB lignin and cellulase, and therefore, decreased non-productive adsorption of cellulase on DA-SCB lignin and enhanced productive adsorption of cellulase on DA-SCB cellulose. [ABSTRACT FROM AUTHOR]

• Highly stretchable hydrogel was prepared from biomass lignin. • LCP hydrogel performed excellent viscoelasticity and stretchability. • Compared with PVA hydrogel, the elongation rate of LCP increased by 20 times. • LCP hydrogel showed good thermosensitivity and electrical conductivity. In this study, hydroxyethyl cellulose (HEC) and polyvinyl alcohol (PVA) as the framework, borax as the cross-linker, and biomass lignin from pulping black liquors and biorefinery as the plasticizer were used to synthesize the lignin-based HEC-PVA (LCP) self-healing conductive hydrogel with highly stretchable and thermosensitive properties by the one-step fabrication method. Compared with the PVA hydrogel, the maximum storage modulus and the elongation rate was increased by 7 times and 20 times, respectively. Uniformly distributed lignin could increase the mobility and distance of polymer molecular chains, therefore improve the viscoelasticity and stretchability of the LCP self-healing hydrogel. The LCP hydrogel could recover to the original state in 12 s after 10000% shear strain for 4 cycles. The LCP hydrogel also presented good thermosensitivity and electrical conductivity, and were very promising for applications in the fields of 3D printing and wearable electronic devices, that broadened the efficient utilization of biorefinery lignin. [ABSTRACT FROM AUTHOR]