Optimization of Monacolin Production in a Controlled System

Monascus purpureus is a fungus that had been cultured on the rice in eastern Asian countries since thousands years ago and used as a food for long years. The fungus produces very valuable metabolites with polyketide structure. The most important metabolite is Monacolin K, lovastatin or competitive inhibitor of 3-Hydroxy-3-Methylglutaryl-Coenzyme A reductase (an affective enzyme in cholesterol synthesis). This metabolite has various properties including reducing blood cholesterol, preventing infection, and treatment of progressive renal disease, a variety of tumors, vascular diseases and bone fractures. In this study, Monascus purpureus PTCC5303 has been used for lovastatin production in liquid fermentation. The nutritional concentrations that were significant in biomass and lovastatin production including maltose and MgSO4 were optimized by Response Surface Methodology in a mili-bioreactor. The optimum concentration of maltose and MgSO4 was obtained as 10 gl^-1 and 0.78 gl^-1, respectively. According to our results, maximum lovastatin production under optimum conditions including maltose 10 gl^-1, peptone 5 gl^-1, MgSO4.7H2O 0.78gl^-1, MnSO4.H2O 0.5 gl^-1, KH2PO4 4 gl^-1, thiamine 0.1 gl^-1, and pH=7 at 30 °C, 130 rpm and flow rate 1.8 l min^-1 was obtained to be 309 μg l^-1 after 10 days of fermentation period.