Decolorization of molasses alcohol wastewater by thermophilic hydrolase with practical application value.

Abstract The aim of this work was to explore the ability of cutinase in the decolorization of molasses wastewater. Thermophilic cutinase from Thermobifida alba eliminated 76.1–78.2% of colorants and exhibited the highest decolorization efficiency amongst all of the cutinases tested. Cutinase from Thermobifida alba was immobilized on an affordable and efficient modified chitosan carrier and achieved a decolorization yield of 79.3–81.2%. This cutinase removed 66.3–71.1% of pigments and lasted continuously for 5 days. Importantly, it was also shown to continuously and effectively remove COD and BOD5. Compared to other enzymes, the immobilized cutinase from Thermobifida alba had the advantage of being low-cost and had a high expression level and activity. The results confirmed the decolorization occurred by destroying the conjugated system of melanoidins via an addition reaction by cutinase from Thermobifida alba. Thus, this study contributes a more practical and efficient approach to enzymatic decolorization of molasses wastewater.