COMBINED INFLUENCE OF TEMPERATURE, A(W) A ND PH ON THE PROTEASE ACTIVITY OF PSEUDOMONAS SPP AND BACILLUS SPP

The factors affecting protease activity were investigated on certain m edia. Five strains of Bacillus (B.) cereus, four strains of B. subtili s, five strains of Pseudomonas (Ps.) aeruginosa and two strains of Pa. fluorescens produced the proteases that were tested. The enzyme activ ity was evaluated under 32 different combinations of temperature (2 an d 7 degrees C), water activity (a(w)) (0,80-0,98) and pH (4,0-7,3). A decrease in water activity and pH and/or temperature caused a decrease in protease activity. It appeared that the combined effect of tempera ture, aw and pH influences enzyme production significantly compared wi th the influence of single environmental factors. Temperature plays th e crucial role in these reactions. Enzyme activities could be observed even at low temperature. Although the exoprotease of Ps. spp. showed intense activity at refrigeration temperature, low pH and aw, Bacillus proteases were comparably less active under the same conditions, but nevertheless proved to be significant.