Fig. 3

SEC profiles of softwood (a) and hardwood (b) lignosulfonates treated for 24 h with native VP and its W164S variant and control without enzyme, and sulfonated polystyrene standards (c). Lignosulfonate samples (12 g L⁻¹) after a 24-h treatment with 1.2 µM native VP (green line) and its W164S variant (dashes) in presence of 9.5 mM H₂O₂, and the corresponding softwood (red) and hardwood (blue) lignosulfonate controls without enzyme, were analyzed in a Superdex-75 column using 0.15 M NaOH as eluent (0.5 mL·min⁻¹) and detection at 280 nm. Sulfonated polystyrenes (Mp 78,400, 29,500, 10,200 and 4210 Da, from left to right) were used as molecular mass standards in c (arrow shows the excluded blue dextran elution volume)