Reduction of proteolytic breakdown in microbial homogenates.

Proteolytic enzymes are present in many biological raw materials used for the production of proteins and peptides. Such enzymes are active not only in homogenates of bacteria and yeast but also in ascites liquid and cell culture media used for the production of monoclonals. A new protease substrate was used to determine protease activity in homogenates of E. coli and baker's yeast, which are useful for the production of therapeutically valuable polypeptides. Using this substrate we found that cooling and the addition of protease inhibitors had little effect on the proteolytic activity. Most of the proteolytic activity however could be adsorbed to hydrophobic gel media. Data is given on the protease adsorption at different temperatures and ionic strengths.