Low-cost solid-state fermentation to improve mycophenolic acid synthesis

Mycophenolic acid (MPA) is an immunosuppressive/antibiotic drug, biologically produced by the fermentation of Penicillium brevicompactum as its secondary metabolite using submerged (SmF) and solid-state (SSF) fermentation processes. In this study, the SSF of P. brevicompactum (MTCC 1999) was done in optimised conditions to enhance MPA yield. Substrates including basmati and non-basmati rice, barley, oats, cornflakes, rice bran, and wheat bran were 80% moistened and sterilised. The active-spore suspension was inoculated and incubated for 30 days. Wheat bran has been shown to produce the highest MPA yield in bench-scale studies. Therefore, wheat bran was subjected to large-scale MPA production. The indigenous fermentation bags were used in the large-scale SSF process. The MPA production was increased from 0.02 mg/g in bench-scale SSF to 9.5 mg/g in large-scale SSF in 15 days of incubation. The MPA increase is nearly 9.48 mg/g. This paper presents an improved SSF process for enhanced MPA production.