Elucidating the synergistic action between sulfonated lignin and lytic polysaccharide monooxygenases (LPMOs) in enhancing cellulose hydrolysis

Modern enzyme cocktails often include lytic polysaccharide monooxygenase (LPMO) as an accessory enzyme that enhances cellulose accessibility during hydrolysis. Although lignin is known to generally impede cellulose hydrolysis, previous research has demonstrated lignin's potential to act as a co-factor in boosting LPMO activity and that the negative impact of lignin limiting enzyme accessibility can be mitigated by sulfonated. When sulphonated lignin was added to microcrystalline cellulose (Avicel) the activity of the lytic polysaccharide monooxygenase (LPMO) was boosted, as determined when using a quartz crystal microbalance and dissipation monitoring (QCM-D). Further assessment via scanning electron microscopy, Simon's staining and nitrogen adsorption indicated that the addition of sulphonated lignin with the LPMO also increased cellulose accessibility.