SIMULTANEOUS PRODUCTION OF AMYLASE AND PROTEASE BY AEROMONAS-HYDROPHILA PC5, A PSYCHROTROPHIC BACTERIUM

Aeromonas hydrophila PC5, a soil isolate, produced amylase and protease on a variety of substrates. The highest titers of both enzymes were observed with casein at 20 degrees C and at pH 7.0. Unlike amylase, the protease was thermostable and retained about 50% activity at 60 degrees C after 120 min of exposure. Of the metal ions tested, only protease was stimulated by 10 mM Fe+2. EDTA and iodoacetamide inhibited both of the enzymes. Partial purification with DEAE-cellulose revealed that the enzyme complex consists of an alpha-amylase, a beta-amylase and a metalloprotease.