Different laccase detoxification strategies for ethanol production from lignocellulosic biomass by the thermotolerant yeast Kluyveromyces marxianus CECT 10875

In this work, laccase enzymes were evaluated to detoxify the whole slurry from steam-exploded wheat straw. For it, two different strategies, laccase treatment before or after enzymatic hydrolysis, were employed. The detoxification efficiency was analyzed on enzymatic hydrolysis and fermentation levels by the thermotolerant yeast Kluyveromyces marxianus. Laccases reduced phenolic compounds without affecting weak acids and furan derivates. A lower glucose recovery was observed when laccase treatments were carried out before enzymatic hydrolysis, phenomenon that was not showed after enzymatic hydrolysis. In contrast, both laccase treatment strategies enhanced ethanol concentrations, reducing significantly the lag phase of the yeast and allowing substrate loading increments of saccharification and fermentation broths.

► Laccases were used to detoxify the whole slurry from steam-exploded wheat straw for ethanol production. ► Laccases removed phenolics from toxic compounds without affecting weak acids and furan derivates. ► Laccases enhanced ethanol concentrations, reducing the lag phase of yeast. ► Laccases allowed substrate loading increments of saccharification and fermentation broths.