EFFECT OF PHYSICAL AND CHEMICAL MUTAGENS ON PRODIGIOSIN PRODUCTION BY LOCALLY ISOLATED SERRATIA MARCESCENS

In order to isolate prodigiosin produced by Serratia marcescens, a total of 57 soil, water, and sewage samples were collected from different environments. From these samples, thirty bacterial isolates were obtained, five of them were identified as Serratia marcescens according to results of cultural, morphological characteristics and biochemical tests. Ability of these isolates in prodigiosin production was examined to select the efficient isolate in prodigiosin production. Results showed that all of these isolates are prodigiosin producers, and among them S.marcescens S11 was the most efficient in prodigiosin production, which the prodigiosin activity in its culture filtrate was 200 U/cell. Ability of S. marcescens S11 in prodigiosin production was enhanced by mutagenesis with physical and chemical mutagens. Physical mutagenesis was achieved by using UV irradiation, while chemical mutagenesis was achieved by using Mitomycin C. Results showed that subjection of S.marcescens S11 to physical and chemical mutagens leads to obtain several bacterial mutants characterized with their high ability in prodigiosin production. The prodigiosin activity in culture filtrate of the most efficient over-producer mutant(S11H7) arise after physical mutagenesis was 350 U/cell, while the prodigiosin activity in culture filtrate of the most efficient overproducer mutant (S11H54) arise after chemical mutagenesis was 400U/cell in comparison with the productivity of wild-type (200 U/cell).