| Summary: | 碩士 === 大葉大學 === 食品工程研究所 === 89 === ABSTRACT
In this study, monacolin K was produced by Monascus ruber CCRC 31535 in flask culture. The objective of this study was to develop the effects of the food-grade rice-yeast powder or rice-vegatable oil complex media on monacolin K production by M. ruber. Several different strategies of manipulating variables, such as culture temperature, initial pH and volume of the complex medium, were investigated. It was found that the optimum culture medium was the rice-vegatable oil complex medium. The temperature and medium volume in 250-mL flask culture were at 25℃and 50 mL, respectively. The optimum initial pH of the rice complex medium was to be 5.0-6.0. The optimum initial pH for 0.06 g/mL rice particle in the complex medium was to be 5.0, while that for 0.20 g/mL rice particle was to be 6.0. In general, the rice particle, rather than the rice powder, was considered to be a suitable composition form for improving yield of monacolin K.
Finally, the result indicated that the addition of vegatable oil in the rice complex medium was found to increase the monacolin K production. The maximum yield was 0.058 mg/mL when 0.10 g/mL rice particle, 0.036 mL/mL vegatable oil, 0.13 g/mL sucrose, 0.01 g/mL yeast extract was used in the complex medium. By using the rice-vegatable oil complex medium describle above, the maximum monacolin K yield, 0.023 g/L, was obtained at the 9th day under controlling 400 rpm stirred speed in a 5-L stirred tank fermentor. This research demonstrated the food-grade rice complex medium was worth improving the yield of monacolin K by using response surface methodology to optimze the composition concentration and to study the fermentation conditions by using a 5-L stirred tank fermentor.
|
|---|
