Extracellular proteinase from Enterococcus faecalis subsp. liquefaciens. I : growth and extracellular proteinase production under different culture conditions

Growth and extracellular proteinase production by Enterococcus faecalis subsp. liquefaciens was studied on several culture media and under different incubation conditions. The organisms grew well and developed extracellular proteinase activity on proteinaceous media, but when it grew on Collins basal medium (lacking of protein), growth was poor and proteinase activity was not detected. The activation energy for growth was estimated to be 116 kJ/mol, the optimum being at 37 degrees C. Proteinase production was not affected by temperature in the range studied (7-45 degrees C). Growth rate was not affected by aeration although a higher amount of microorganisms was observed on shaking the culture during incubation. Likewise, extracellular proteolytic activity was about twice higher in cultures shaken at 2.3 or 3.3 Hz than in those shaken at 0 or 1.3 Hz.