**4.5 Characterization of salt-tolerant acid protease**

Characteristics of proteases purified from the culture medium of *B. subtilis* JM3, *B. megaterium* KLP-98 and *A. oryzae* LK-101 were well studied, while those of the protease from *Rhizopus japonicus* except specific activity were not reported. Thus, the characteristics of the three kinds of proteases were compared and discussed in this study.
