# Laccase-Mediated Incorporation of Xylans and Lignin-Carbohydrate Complexes into High-Yield Eucalyptus Kraft Fibers

## TL;DR

This paper explores using water-soluble products from corn stover and sugarcane bagasse to modify eucalyptus kraft fibers, improving their wetting properties for brown tissue paper.

## Contribution

A novel method for incorporating feruloylated arabinoxylans and lignin-carbohydrate complexes into fibers using laccase-mediated reactions.

## Key findings

- Fibers incorporated up to 15.4 g of water-soluble products per 100 g of pulp.
- Paper sheets showed decreased water contact angles, indicating improved wettability.
- XPS analysis confirmed increased carboxyl and ester groups from xylan and LCC incorporation.

## Abstract

Water-soluble products derived from biomass processing
hold significant
potential to enhance biorefinery viability due to their versatile
applications. However, their use in the modification of paper products
remains underexplored. Here, corn stover and sugarcane bagasse provided
water-soluble products being incorporated into high-yield eucalyptus
kraft pulps. The water-soluble products were extracted from ball-milled
or alkaline-sulfite pretreated biomass using a xylanase-assisted procedure.
Feruloylated arabinoxylans and lignin-carbohydrate complexes (LCCs)
predominated in the extracted mixtures. The water-soluble products
were incorporated into the fibers using laccase-mediated reactions.
The fibers incorporated up to 15.4 g of water-soluble products/100
g of pulp, depending on the biomass source and pretreatment type.
The highest incorporation levels were achieved with the water-soluble
products recovered from ball-milled sugarcane bagasse. This fraction
underwent significant polymerization of feruloylated arabinoxylans
during laccase treatment. Paper sheets prepared from fibers with high
levels of xylan and LCCs exhibited decreased water contact angles,
indicating their potential suitability for a more wettable brown tissue
paper. High-resolution X-ray photoelectron spectroscopy revealed an
increase in the content of carboxyl and ester groups, corroborating
the incorporation of xylans and LCCs into the fibers. The study presents
novel strategies for modifying fiber properties through the use of
agricultural byproducts.