The cellular location of proteolytic enzymes of Bacillus intermedius

The activities of proteinases in the culture fluid and cellular fractions o f Bacillus intermedius 3-19 grown under various conditions were studied. Th iol-dependent serine proteinase was the prevalent enzyme in the total pool of extracellular proteinases (70%); its catalytically active form was also detected in the cell membrane and, during active enzyme production, in the cell wall. Another enzyme, glutamyl endopeptidase (10% of the total pool), was detected in the cell membrane; it was also found in the cell wall and c ytoplasm during active enzyme secretion into the growth medium. The product ion of these enzymes was maximal on medium containing inorganic phosphate a nd gelatin and decreased 2- to LC-fold on medium with glucose and lactate. The level of activity of extracellular enzymes correlated with that of corr esponding membrane-hound proteins. The addition of CoCl2 (2 mM) into the me dium caused an essential increase in extracellular glutamyl endopeptidase a ctivity and promoted the release of the membrane-bound enzyme into the cult ure fluid. Proteolytic activity towards casein was also detected in the cyt oplasm. The proteinases localized in the cytoplasm were shown to differ in their properties from those secreted.