Proteolytic enzymes produced in liquid media by Fusiformis nodosus

Abstract

Four strains of Fusiformis nodosus examined were shown to produce proteolytic enzymes digesting azocasein. When enzyme activity was plotted against the age of culture, the curves obtained showed two maxima, the first coinciding with the end of the logarithmic phase of growth, and the second with the end of the stationary phase. Enzyme preparations obtained at either of these stages of growth had similar properties, and digested casein and haemoglobin. The addition of sulphydryl compounds was without effect on the casein-digestive activity of either preparation, but enhanced the digestion of haemoglobin. The optimum pH for casein digestion by either preparation was about 9.5. Both preparations had similar stability to treatment by acid or alkali and both were inactivated by exposure to temperatures greater than 50°C.