Aryl carboxylic acid reduction and further reactions with GABA and glucose promoted by whole cells of Xylaria arbuscula

Xylaria arbuscula was collected from a "Cypress" tree, Cupressus lusitanica. The whole cells of this endophytic fungus were used in screening for microbial bioreduction of aryl acids. Different p-substituted benzoic acids were evaluated. However, only p-bromobenzoic acid, p-chlorobenzoic acid and p-nitrobenzoic acid were converted to their corresponding alcohols. Aryl acid metabolism of X. arbuscula included GABA incorporation and glycosylation when the substrates were p-bromobenzoic and p-chlorobenzoic acids were also observed. The substrates p-hydroxybenzoic and p-aminobenzoic acids were not transformed. These results could suggest that electron-withdrawing groups at para orientation activate the substrate for reduction. (C) 2015 Elsevier B.V. All rights reserved.