Extraction of Cell‐bound Hyaluronidase and Aminopeptidase From Streptococcus Mitis, Atcc 903

Different methods for disintegration of Streptococcus mitis, strain ATCC 903 were tested for extraction of hyaluronidase and aminopeptidase. Two methods were found effective, autolysis and freeze‐pressing. Reproducible conditions for the extraction of both enzymes were autolysis for 20 hours at 37° C in 0.05 M phosphate buffer at pH 6.8 in the presence of chloramphenicol (100 μg/ml). The amounts of enzymes released per unit of autolysed cells were not affected by the incubation temperature. Disintegration by freeze‐pressing reduced the specific activity of hyaluronidase by 70 per cent as compared to the autolytic procedure. Although the yield of aminopeptidase in extracts prepared by freeze‐pressing was approximately equivalent to that in autolytic extracts, the stability of the enzyme was reduced.