Structural Changes in Wool Degraded by the Ringworm Fungus Microsporum Gypseum and Other Microorganisms

Abstract

Observations in the literature concerning the effects of certain fungi and bacteria on the structure of the wool fiber are scattered and contradictory. In this study, using the fungus Microsporum gypseum and the bacterium Pseudomonas sp., it has been observed that the scale cells of the wool are not dissolved. On the basis of microscopic observations supplemented by breaking-strength determinations of degraded cloth and by loss in dry weight of degraded wool, it is concluded that the weakening of wool subjected to microbiological attack is due to effects upon the intercellular substance and upon the cortical cells. When degraded wool is wet, its breaking strength seems to be limited by the strength of the intercellular substance, whereas the tensile strength of such wool which has been dried apparently is determined by a weakening of the cortical cells. It has been demonstrated that the hyphae of M. gypseum penetrate the wool fibers and grow parallel to the fiber axis, apparently between the cortical cells. Presumably penetration occurs through the fiber ends or through breaks in the epithelium.