Enhancement of Serrapeptase Hyper Producing Mutant by Combined Chemical and UV Mutagenesis and its Potential for Fibrinolytic Activity

Serrapeptase is a proteolytic enzyme with many favourable biological properties like anti-inflammatory, analgesic, anti-bacterial, fibrinolytic properties and hence, is widely used in clinical practice for the treatment of many diseases. The activity of microbial enzymes is usually low and hence enhancing the enzyme activity is an integral and crucial area of research. In this study, a mutant with higher serrapeptase activity was developed by multiple exposures of Serratia marcescens to Ultra Violet radiation (UV) and Ethyl methyl sulfonate (EMS) individually and also a combination of both the methods was used. The mutant exposed only to UV radiation for 40 seconds indicated an increase in enzyme activity of 3234.9 EU/mL in comparison to wild-type strain (2770 EU/mL). The mutant exposed to only EMS indicated a very small increase in enzyme activity of 2797 EU/m L in comparison to wildtype strain (2770 EU/mL) but a lower enzyme activity than the UV mutant. Combinational exposure of wild-type to UV and EMS gave a better mutant with an enzyme activity of 3437.6 EU/mL which was higher than all the above methods. Optimization of temperature, incubation period and pH was studied in the wild type and mutant strains and found slight increase in activity in the mutant strain than the wild strain. The mutant serrapeptase has a molecular weight of approximately 50kDa and also exhibited fibrinolysis activity with a maximum blood clot lysis of 35% with 100 U/mL of Serrapeptase.