Synthesis of phosphofructokinase was decreased in pestilential microbe if cultivation temperature was increased from 28 degrees to 37 degrees. Aeration of cultural fluid effected slightly on the enzyme production. Glucose, added to cultural fluid, decreased synthesis of phosphofructokinase in virulent strain and increased it in avirulent one. Phosphofructokinase activity from pestilential microbe was inhibited by ATP, citrate, 3-phosphoglycerate, by Ca2+ and Mn2+. AMP and lesser ADP reduced the effect of ATP and citrate on the enzyme, but when ATP was maintained in reaction mixture at non-inhibitory concentration these substances decreased phosphofructokinase activity.