Cyclosporin ‘A’ is an important immunosuppresive drug used in organ and bone marrow transplantations.
Nine isolates of Aspergillus terreus was used for the production of Cyclosporin ‘A’ by submerged
fermentation in this study. The highest drug yielding isolate FCBP-58 was subjected to both physical
and chemical mutation to increase the biosynthetic capabilities of Cyclosporin ‘A’. In this study,
mutation was carried out by ultraviolet radiation (254 nm) and alkylating agent ethylmethane sulphonate
(EMS). UV 5 min time treatment was proved to be the best treatment because most of the resulted
mutants showed enhancement in drug production. Chemical treatment of 200 µg/ml produced best
mutants, among which MC 3.2 showed maximum increment of 885% in Cyclosporine ‘A’ production
when compared to the parental isolate.