Applications of Trametes versicolor crude culture filtrates in detoxification of biomass pretreatment hydrolyzates

•Poplar and rice straw hydrolyzates were treated with crude T. versicolor filtrates.•Phenolic inhibitors decreased by 94% in poplar and 76% in rice straw hydrolyzates.•Rice straw xylopentaose was reduced by 67 % with crude T. versicolor filtrates.•Crude culture filtrates had efficiencies comparable to commercial pure laccase.

Laccases have wide range of substrate specificity and find applications from pulp industry to waste water remediation. Laccases have also been used in combined pretreatment of biomass hydrolyzates to remove enzymatic and fermentation inhibitors. In this study, laccase production by Trametes versicolor strains isolated from different regions of the United States was induced using copper salts. T. versicolor crude culture filtrates (CCF), without any purification step, were tested for removal of model inhibitor compounds as well as in poplar and rice straw pretreatment hydrolyzates. Phenolic inhibitors were removed by 76% and 94% from the dilute acid hydrolyzates of rice straw and poplar, respectively, when incubated with the CCF for 12 h, at room temperature. Xylo-oligosaccharide concentrations present in rice straw hydrolyzates were reduced by 64% when incubated with T. versicolor CCF. T. versicolor CCF could be a low cost technology for decreasing enzymatic and fermentation inhibitors.

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