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Highlights: [•] EstBC from Auricularia auricula-judae established a new class of esterases. [•] The unique substrate profile and partial sequences were determined. [•] EstBC acted on both, benzoates and cinnamates efficiently. [•] The enzyme may be useful for hydrolyzing/synthesizing flavor esters or other fine chemicals. [Copyright &y& Elsevier]

Abstract: Little is known on basidiomycete sources of feruloyl esterases (FAEs), although many wood-rotting representatives of these fungi typically grow on feruloyl-rich substrates. A major reason is that the almost ubiquitous presence of laccases interferes with the detection of FAE activity. Laccases polymerize the liberated ferulic acid (FA) in situ, thus detracting the product of enzymatic hydrolysis from its detection. A rapid HPLC-UV method was developed to detect the loss of FA, but also to quantify the hydrolysis of FA esters. The method allows at the same time to evaluate the substrate specificity of a FAE. Forty one basidiomycetes were tested for their FAE activities, and 25 out of the set were positive. The basidiomycetes hydrolyzing cinnamates with the highest conversion rates were Auricularia auricula-judae and Marasmius scorodonius. Moreover, a new FAE inducer, the nonionic detergent Tween 80, was found. This is the first comprehensive study on basidiomycete sources of FAEs. [Copyright &y& Elsevier]