Diversity of Culturable Fungi in Two-Phase Olive Mill Waste, a Preliminary Evaluation of Their Enzymatic Potential, and Two New Species.

This study investigates the diversity and provides a preliminary evaluation of the enzymatic potential of culturable fungi present in two-phase olive mill waste (TPOMW), a lignocellulose- and phenolic-rich agro-industrial by-product generated in large quantities in olive oil-producing countries. Ninety-four isolates, representing 31 species of the phyla Ascomycota, Basidiomycota, and Mucoromycota, were obtained and identified by using ITS, 28S, 1-α, 2, 2, , and/or sequences. Among the identified taxa, two new species within the Harzianum clade, namely (phylogenetically related to and ) and (phylogenetically related to ), were described following a multilocus phylogenetic analysis combined with a study of their morphoanatomical features. A rather high phylogenetic divergence was detected in , and , while , , and were recorded for the first time in TPOMW. A preliminary screening revealed 29 species with cellulolytic and/or xylanolytic activities; 26 species displayed dye decolorization capacity, while ligninolytic and laccase activities were restricted to a few taxa. The most promising degraders of lignocellulosics included strains of , , , and . Fungi detected in TPOMW are promising biotechnological tools to be exploited in the frame of circular economy applications.