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

Abstract

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°C and at pH 7.0. Unlike amylase, the protease was thermostable and retained about 50% activity at 60°C after 120min 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 α-amylase, a β-amylase and a metalloprotease.