Summary: | 碩士 === 大葉大學 === 食品工程研究所 === 88 === In this study, response surface methodology (RSM) was used to optimize the concentrations of the compositions (rice powder, peptone, glycerin and glucose) of the rice-glycerin complex medium for Monascus ruber CCRC 31535. The coexistence of Monascus intracellular and extracellular secondary metabolites (red pigments and monacolin K) was also studied. For the intracellular monacolin K production, the effects of peptone and glycerin on monacolin K production were only significant. In addition, analysis of variance indicated that the quadratic terms of rice powder, peptone and glucose in the quadratic model were significant. For the extracellular monacolin K production, the effects of rice powder, peptone and glucose were significant. The interaction red pigments, analysis of variance indicate that the effects of rice powder, peptone and glycerin on the intracellular and extracellular pigment production were only significant. It also indicated the interaction terms of rice powder-glycerin and peptone-glycerin were significant. In addition, the quadratic term of glycerin in the quadratic model was significant. For the extracellular red pigments, the interaction term of rice powder-peptone in the quadratic model was significant.
In this study, the productivity of the intracellular secondary metabolites ( monacolin K and red pigments ) was higher than that of the extracellular ones. At present, the most suitable composition for the intracellular monacolin K production was found to be 34.4 g/L rice powder, 10.8 g/L peptone, 36.4 mL/L glycerin, 129.2 g/L glucose, 2 g/L KNO3 and 1 g/L MgSO4.7H2O. With these compounds, the production was 0.157 mg/mL after 10 days of cultivation, while the extracellular monacolin K production was 0.33 μg/mL. The intracellular red pigment production was 3.488 mg/mL, while the extracellular one was 0.113 mg/mL. Whith the compounds described above.
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