Enzymes of some wood-rotting polypores

Abstract

Very few Polypores have been studied with regard to their enzymes, though enzymes are the chief weapons with which these fungi invade the plant cells and bring about a very great amount of damage to logs, timbers, and trees. In 1895, Bourquelot and Herissey (1897) investigated the enzymes from the juice of Polyporus sulphureus , and in 1899, Czapek (1899) discovered the lignin-destroying enzyme in Merulius lacrymans . Two years later, Kohnstamm (1901) made some attempts to determine the enzymes of Merulius lacrymans and Armillaria mellea , but his results were inconclusive as the technique of enzyme chemistry then was not fully developed. Subsequently, Buller (1906) brought out a list of enzymes present in the expressed sap of the young fruit-bodies of Polyporus squamosus growing in nature. In recent years Zeller (1916), Schmitz (1920, 1921, 1925), Lutz (1930, 1931), Schmitz and Zeller (1919), Nutman (1929), Yamano (1931), Venkatarayan (1936) and others have carried out important investigations in this line. From the literature cited above it appears that only a very few Polypores (about a dozen) have been studied with regard to their enzymic activity. In the present paper the more important enzymes of eight species of wood-destroying Polypores , viz. Polyporus ostreiformis, Polystictus hirsutus, Daedalea flavida, Polystictus sanguineus, Trametes lactinea, Polystictus leoninus, Trametes cingulata and Polyporus zonalis have been studied in detail in artificial culture. The enzymic activity, both intracellular and extracellular, was measured at three different stages of growth, viz. (1) young vegetative mycelium, (2) mycelium about to bear fruits, and (3) mycelium with fruit-bodies. Side by side, the enzymes contained in mature fruit-bodies collected from nature were also studied. The nature of decay of mango-wood blocks inoculated with pure cultures of these Polypores was also studied. Incidentally, the change of p H values after growth, the production of fruit-bodies in artificial cultures and cultural characters in liquid medium were noted.