Improvement of penicillin G acylase expression in Escherichia coli through UV induced mutations

We used ultraviolet (UV) radiation to induce mutation in three locally isolated strains of Escherichia coli. Different dilutions of bacterial cultures were exposed to UV lamp of 254 nm wavelength for different time intervals at varied distances ranging from 5 to 210 sec and 5 to 100 cm. Viable colonies were screened for mutants with an increased production of penicillin G acylase (PGA) and a reduced production of β-lactamase, which are the desired properties of PGA producing industrial strains. A survival curve was made to get optimum exposure time and distance. The survival percentage for ea...