Studies in Diatrypaceae: the new species Eutypa microasca and investigation of ligninolytic enzyme production

Abstract

In this study the extracellular production of ligninolytic enzymes by xylariaceous and diatrypaceous species from Argentina was investigated. Among them, a new species (Eutypa microasca) was evaluated. Its morphological characteristics (e.g.: very small asci), along with the molecular analyses, support the hypothesis of the new taxon. Ligninolytic enzyme production by several saprophytic and endophytic strains belonging to the genera Xylaria, Eutypella, Eutypa and Peroneutypa was assessed on solid medium supplemented with different dyes (Poly R-478, Azure B and Malachite Green) and under submerged fermentation in copper amended malt extract/glucose medium. All the strains produced laccase in liquid cultures, and seven out of nine also produced Mn-peroxidase (highest titres detected 113 U/l). Only 5 of the strains assayed could not decolorize Malachite Green. This is the first report on laccase and Mn-peroxidase production by the members of the Diatrypaceae and contributes to the knowledge on ligninolytic enzyme production in the members of the Xylariaceae, scarcely studied up to date.