The enzyme patterns of Ascomycota and Basidiomycota fungi reveal their different functions in soil

The enzyme profile of a series of fungal isolates belonging to Ascomycota and Basidiomycota was analysed for a better understanding of the functional significance of their changes in soil with a specific focus on the carbon cycle. Two synthetic populations of Ascomycota and Basidiomycota isolates were compared on the basis of their enzymatic profiles. The activities of twenty-five enzymes extracted from the mycelium of pure fungal colonies were quantified in microplates using fluorogenic substrates. The enzyme activities were divided by the dsDNA content of each fungal colony and subjected to multivariate analysis. Ascomycota and Basidiomycota differed significantly (P = 0.0001) in enzyme profile. Ascomycetes showed a broader enzymatic profile than Basidiomycetes. In the latter, seven out of the twenty-five enzyme activities detected in Ascomycetes were absent, including the enzymes of phosphorus and sulphur metabolisms and alpha-galactosidase. To the contrary, many enzymes responsible for plant polysaccharide degradation, such as alpha-galactosidase, beta-mannosidase or xilosidase were detected in the isolates of both fungal phyla. This indicates likely underestimated ability of Basidiomycetes to degrade plant polysaccharides, apart from their specific ability to decompose lignin. To the contrary, the widest enzyme profile of Ascomycota and their highest enzymatic inter- and intra-genus variability indicates their higher adaptability to metabolize different crop residues and litters.