Abstract
The influences of stability of protease activity in the presence of surfactants upon the removal of blood protein stains were studied by using the fabrics soiled with bovine blood (whole blood and blood serum) .
In the washing of blood protein stains on the fabrics by anionic surfactant·protease system using DBS and AOS as surfactants, different from the case of nonionic surfactant·protease system using APE, the negative removal effects were found because of the decrease of activity of protease causing by the kinds of anionic surfactants and the concentration, and also the temperature of washing solution. On the other hand, when alkaline protease with protease activity of 10PU/ml produced by Bacillus subtilisin var. were used in the washing by surfactant·protease system at 40°C, the removal efficiency of blood protein stains were inversely increased although the protease activity was reduced in the presence of surfactants. This is because the detergency of blood protein stains are remarkably affected by the amount of protease remaining in the washing solution, the substrate specificity and temperature characteristics of protease.
