Immobilization technique for enhanced production of the immunosuppressant mycophenolic acid by ultraviolet and gamma-irradiated Penicillium roqueforti

Abstract

Aims: Different entrapment matrices were screened to immobilize two strains of Penicillium roqueforti (AG101 and LG109) for more effective production of mycophenolic acid (MPA). Further improvement in the MPA productivity from immobilization of spores and mycelia was adopted by UV and gamma irradiation.

Methods and results: Penicillium roqueforti strains were immobilized in different entrapping carriers and used for MPA production in shake flask cultures. Maximum MPA production was achieved on using an alginate concentration of 3·0% (w/v) and a mycelial fresh weight of 10% (w/v). MPA produced by alginate-immobilized spores and mycelia was almost double in comparison to the free system. The MPA-producing ability of immobilized AG101 and LG109 strain was significantly enhanced by mutagenesis through irradiation by UV (254 nm) for 120 and 90 min, respectively and gamma rays at 0·75 KGy. The feasibility of MPA production in a semi-continuous form by immobilized cells as affected by irradiation was adopted.

Conclusions: MPA production by immobilized spores and mycelia was more intensified by UV and gamma irradiation. Moreover, the immobilized cell culture was superior to free-cell culture.

Significance and impact of the study: These findings indicate the future possibility to reduce the cost of producing fermentation-based drugs.

Keywords: Penicillium roqueforti; UV radiation; calcium alginate; gamma radiation; immobilization; mycophenolic acid.