Some Characteristics of a Proteolytic System from Phymatotrichum omnivorum.

The existence of proteolytic enzymes has been shown in 4 strains of Phymatotrichum omnivorum of varying stages of pathologic and physiologic vigor. One other strain failed to exhibit proteinase production in laboratory culture. Various properties of the enzymes from 2 strains have been studied. The enzymes were optimally active at pH 4.5 to 5.0, and required a divalent metal ion. This requirement could be met by Co++, Zn++, Ni++, Mg++, Mn++ or Ca++ ions; Fe+++ ions were inhibitory. Slight inhibition resulted from the presence of reducing agents, and 0.001 m diisopropyl-phosphofluoridate reduced proteolysis partially. The enzymes from both strains were inactivated fairly quickly at 70°C.