Effect of Laccase Dosage on Enzymatic Hydrolysis of Steam- Exploded Wheat Straw

When laccases are applied for detoxifying steam-exploded slurries, enzymatic hydrolysis is affected. In this study, 10% (w/v) of dry weight (DW) slurry or water insoluble solid fraction were subjected to 48 h enzymatic hydrolysis in the presence of different laccase loadings (0.1, 0.5, 5 or 10 IU/g DW). All laccase dosages higher than 0.1 IU/g DW significantly inhibited glucose recovery. Nevertheless, half of the amount of phenolic compounds present in steamexploded slurries was removed with 0.1 IU/g DW of laccase, while 75% of phenolic compounds were efficiently eliminated when employing 0.5 IU/g DW laccase. These findings suggested that, in order to avoid enzymatic hydrolysis inhibition, laccase dosage has to be kept as low as possible for detoxifying steam-exploded wheat straw slurry.