CELLULOLYTIC, XYLANOLYTIC, AND PECTINOLYTIC ACTIVITIES OF MYXOMYCETES

Abstract

The surface cultures of 19 myxomycete strains-17 associated with bacteria, and Physarum polycephalum and Symphytocarpus sp. as axenic ones-were investigated for their carboxymethylcellulose (CMC)-, pectin- and, for the first time, xylan-degrading capacities and their ability to destroy filter paper. Enzymatic activity was determined as the release of reducing sugars from the three carbohydrate substrates by "enzyme extracts" from the corresponding plasmodia; the destruction of filter paper was assessed optically. While CMC- and xylan-decomposing enzymes were found in all strains tested, only Stemonitis axifera could break down highly esterified pectin. Axenic myxomycetes lacked pectinase and C₁-cellulase, since pectinolysis and degradation of filter paper ("native" cellulose) occurred only with myxomycetes "associated" with bacteria. The problem of working with non-axenic myxomycetes is discussed.