Effect of Gamma Radiation on the Microbial Synthesis of Metal Nanoparticles

Monasus purpureus Monascus is an ascomycete's fungus traditionally used for the production of food colorants, fermented foods and beverages in southern China, Taiwan, Japan, Thailand, Indonesia and the Philippines. Species of Monascus are mainly employed in the production of red rice (Hesseltine, 1965), (Lin, 1973) and food colouring pigments (Wong and Koehler, 1983). This fungus divided into six species namely, M. ruber, M. pilosus, M. purpureus, M. floridans, M. pallens and M. sanguineus. The species with the greatest significance in the food industry are M. ruber, M. purpureus and M. pilosus (Martınkova and Patakova, 1999). The fungus Monascus has been traditionally used in East Asia for the production of fermented rice which served as a red food colorant. Nowadays, this natural dye is also used in European countries. Most studies have addressed the production of red orange oligoketides by the genus Monascus (Evans, and Wang, 1984) and their biological activities (Martfnkovi et al., 1995). M. purpureus has been used commercially to produce valuable secondary metabolites; ankaflavin and monascin (yellow pigments), monascorubrin and rubropunctanin (orange pigments), monascorubramine and rubropuctamine (red pigments) ( Wong et al.,1981), as well as antihypercholesterolemic agent, monacolin K (lovastatin), hypotensive agent, Gamma amino butyric acid (GABA) ( Su et al .,2003), antioxidant compounds, dimerumic acid (Aniya et al.,1999) and an antibacterial compound, 3-hydroxy-4-methoxy-benzoic acid (Wu et al., 2000). Red mold rice also contains unsaturated fatty acids that may also help to reduce serum lipids (Wang et al., 1997), total cholesterol and triglyceride levels levels (Wong et al., 1981). Red mold rice is also contains phytosterols such as beta sitosterol and campesterol (Heber et al., 1999) which are interfere with cholesterol absorption in the intestine (Moghadasian and Frohlich, 1999).The combination of such dietary sterols with statin drugs has been suggested as a more effective means of lowering cholesterol than statin alone (Plat and Mensink, 2001).