[Accumulation in the medium and properties of proteolytic enzymes formed by Nocardia minima]

The accumulation dynamics of extracellular proteinases with plasmin-like and activatory mechanisms of action (belonging to the subtilisin family of the class of serine proteases and to the class of metallo-proteinases, respectively) were followed during the course of growth of Nocardia minima, strain 1. The sequence of the appearance of extracellular proteinases and their activity at various growth phases of the producer suggest their participation in the processes of the morphophysiological transformations accompanying the transition from mycelium to rods and from rods to cocci. The proteinases produced by Nocardia showed specificity to either human or bovine blood fibrin. The specific pattern of Nocardia minima proteinases (absence of chymotrypsin-like enzymes typical of streptomycetes, presence of metalloproteinases typical of bacilli) and the distinctive features of Nocardia minima subtilisins distinguishing them from subtilisins of bacilli and streptomycetes agree well with the intermediate taxonomic position of N. minima.