Solid fermentation of Monascus sp. using rice substrates in production of the pigment, monacolin K and citrinin

• Main Authors: Hua-Yu Teng, 鄧化瑜
• Other Authors: Kow-Jen Duan
• Format: Others
• Language: en_US
• Published: 2004
• Online Access: http://ndltd.ncl.edu.tw/handle/35796704283441917348

碩士 === 大同大學 === 生物工程學系(所) === 93 === In this research, two Monascus sps. (BCRC 31615, BCRC 31499) were choosed for culturing on Japanica and Indica type of rices at 30 ℃ to understand the yields change of pigments and secondary metabolic product, Monacolin K. The brown rice (Japanica type rice) purchased from local market was divided into three parts, the one was polished to remove the bran, the other part was immersing in water for two days to become germinated. The other kind of polished rice (Indica type rice) was also purchased from local market. Samples of the red rice were taken and dried from 6 ~14 th day after inoculated with Monascus sp. Then 1 gram of red rice was extracted with 5 ml ethyl acetate to obtain the pigment, monacolin K, and citrinin. We found that the color of red rice cultured by BCRC31615 was deeper than that from BCRC31499 during the culturing process. The absorbance values of red and yellow pigments were determined with OD500nm and OD400nm. It was found that BCRC31615 has higher yields in pigments than BCRC31499. The brown rice and geminated rice were unfavorable for the synthesis of pigment by BCRC31499. The geminated rice has the highest yields of pigment by BCRC31615. The production curves of monacolin K and pigment had similar trend with time for the brown rice and the germinated rice. 381 mg/kg of monacolin K was achieved for the germinated rice cultured by BCRC31615 at the 12th day of cultivation. While that for the polished Indica rice was 287 mg/kg at the 14th day of cultivation. Monacolin K production from BCRC 31499 was only 34 mg/kg at the 10th day of cultivation for the polished Indica rice. The brown rice and germinated rice were not good in the production of monacolin K. Yield of monacolin K was more by BCRC 31615 than that by BCRC 31499 no matter what kinds of rice were used. Production curve of citrinin has similar trend as that of pigment. Concentrations of citrinin of red rice from BCRC 31615 were in the range of 80~120 ppm for the polished Indica rice and polished Japanica rice and brown rice. The most citrinin (300 ppm) was obtained from the germinated rice which also achieved the most monacolin K from BCRC 31615. It is suggested that some ingradients are in the germinated rice which are beneficial for the production of secondary metabolites.