Thermostable Alkaline Serine Protease Production by the Soil Myxobacterium of Archangium sp. UTMC 4504

Abstract

Myxobacteria have been mainly mining for their drug-like compounds while their essential and versatile protease enzymes is less explored. In this study, in order to obtain myxobacterial strains with the ability to produce extracellular protease, soil samples were collected from different geographical locations of Iran and were cultured on isolation media. The isolates were identified following purification by morphological and molecular methods. All of the identified isolates belonged to Myxococcus, Archangium, Corallococcus and Cystobacter genera. Then, these strains were subjected to the evaluation of protease activity. Archangium sp. UTMC 4504 was identified as a strain with high protease activity (60 Unit). The enzyme was precipitated using up to 60% of the saturation by adding ammonium sulfate in the fermentation supernatant. The optimum temperature of the enzyme was 50–60°C and its optimal pH was 8. The enzyme was inhibited by PMSF, which could indicate its categorization under the serine proteases. Because of the capability of this enzyme in maintaining its activity at high temperatures and alkaline pH, it can be considered a suitable candidate for mass production purposes, including industrial detergents, food industry, or medical applications.