Molecular screening and of extracellular protease producing Serratia marcescens from the different environments of west Mazandaran

Proteases are a useful family of enzymes in microbiology with applications in leather industry, food industry, pharmacy, cleaners, and many other industries. Due to rapid replication, fast growing and facility in their genetic manipulations, microorganisms are used as the main resources of production of proteases. This paper aimed to isolate the Serratia marcescens strains from the natural environments at western Mazandaran, with the ability to produce proteolytic enzymes.

In the present study, 150 natural samples were taken from different depth (0-10 cm) of soils and waters located at western part of Mazandaran. In order to isolate and to identify the microorganisms the samples were grown on Skim milk agar, and the isolates were underwent different biochemical tests. Next, Serratia marcescens strains were screened by molecular tests and 16SrRNA. After isolation of the strains, several time and temperature optimization steps were performed on the most potent enzyme producing strains. As well, approximate molecular weight of the enzymes were measured abased on protein deposition and SDS-PAGE.

Only two isolates were identified as Serratia marcescens. One of the two isolates belongs to a novel strain nominated as Serratia marcescens 424, which recorded in Genbank as KC790390. These two isolates could produce high levels of proteolytic enzyme in 24 hours under 37oC. The highest amount of enzyme belonged to a 52 Dalton molecular weight isolated from Serratia marcescens 424.

Our studies show a high potential of the isolated Serratia marcescens strains in production of protease and Serratiopeptidase. As a result these strains can be useful in various industries.