液态发酵生产水溶性红曲黄色素的条件优化

以红色红曲菌（Monascus ruber）M-7为实验菌株，以色价和色调为评价指标，对液态发酵生产水溶性红色红曲黄色素的条件进行了研究。结果表明，培养基pH值为3～4时，红色红曲菌M-7能合成大量的水溶性红曲黄色素，发酵液呈鲜艳的黄色色调；培养基最优碳源为2%蔗糖，最优氮源为0.2%硫酸铵；水溶性红色红曲黄色素的色价和色调值随着培养时间的延长先升后降，在第8天时达到最高，色价为5.56 U/mL，OD400 nm/OD510 nm为10.29，OD400 nm/OD470 nm为3.93。

Optimization of liquid-state fermentation conditions for the production of water soluble yellow Monascus pigment

Using Monascus ruber M-7 as experimental strain, color value and color tone as evaluation index, the production of water soluble yellow Monascus pigment by liquid state fermentation was investigated. The results showed that when the fermentation medium pH was 3-4, a large portion of water soluble yellow Monascus pigment was synthesized by M. ruber M-7, and the fermentation broths was bright yellow. The optimal carbon source of the medium was sucrose 2%, and the optimal nitrogen source was ammonium sulfate 0.2%, respectively. The color value and the color tone of water soluble yellow Monascus pigment increased in the early stage, decreased in the late stage, and the maximum points were on the 8th day. After 8 d cultivation, the production of water soluble yellow Monascus pigment was 5.56 U/ml, OD400 nm/OD510 nm was 10.29 and OD400 nm/OD470 nm was 3.93.