[Relation between movement of acid or alkaline proteinase from Trichophyton rubrum and the growth of fungus, pH in medium].

We have previously reported that T. rubrum produced a new type of extracellular proteinase in liquid medium containing bovine serum albumin. This enzyme had an optimal pH 4.5 for azocoll. In this paper, we studied about the relation between movement of acid or alkaline proteinase and environmental pH. In the beginning of cultivation, acid proteolytic activity increased radically, and 3 or 4 weeks later, it was decreased. In place of acid proteinase, alkaline proteinase which had an optimal pH 8.0 was increased gradually. During incubation of T. rubrum in bovine serum albumin medium which was adjusted to pH 6.0, the pH of medium was gradually increased to about pH 7.0 toward 4 weeks. The growth of T. rubrum increased until pH in medium was fixed to pH 7.0.