STUDIES ON AMYLASE FORMATION BY BACILLUS SUBTILIS

Abstract

0.01M KCN inhibits O2-uptake of the cell suspension and accelerates cytolysis only under aerobic conditions. 8 x 10-4 M 2,4-dinitrophenol (DNP) slightly increases O2-uptake and acts as a cytolytic agent only under anaerobic conditions. NaN3 gives the KCN-like effects at a higher concentration (10-2 M) and also the DNP-like effects at a lower concentration (8 x 10-4 M) in respects to the respiration and cytolysis. Since 0.1 mg% chloramphenicol completely suppresses the nepherometric cell growth, but gives no effect on anaerobic cytolysis, any possibility of autolytic enzyme formation can be excluded. Simultaneous addition of KCN and DNP to aerobic culture medium shows greater cytolysis than KCN alone, whereby cytolysis is enhanced just when the lag phase of amylase formation has finished. When lysozyme-digestibility in 15% sucrose is examined nepherometrically as the protoplast stability test, the stability of the cells during cultivation is greatly decreased at the time of active amylase formation. KCN or NaN3 inhibits respiration, and presumably produces 02-deficient anaerobic condition, by which a preexisting autolytic enzyme is probably activated to affect the cell wall and protoplasts. This postulated mechanism is discussed in relation to amylase excretion.