两种辅料对固态发酵红曲米莫纳可林K与红曲色素产量的影响

红曲霉在发酵过程中会产生莫纳可林K(MK)和红曲色素(MPs)等多种对人体有益的次级代谢产物。为同时在红曲米固态发酵产物中获得一定量的MK和MPs,实验在大米基质基础上,分别添加豆粕、豆渣两种辅料,对红曲霉MPs-7进行固态发酵培养,分析两种代谢产物产量,并对辅料影响机制进行了探究。结果表明:在发酵基质中添加两种辅料均促进了MK的产生,但同时抑制了MPs的产生。豆粕添加量为质量分数15%时,发酵产物MK产量最高,但几乎无MPs产生;豆渣添加量为质量分数15%时,提高MK产量的同时也保证了一定的MPs产量,且成本比豆粕低,更适合作为辅料添加到红曲霉固态发酵基质中。研究表明:基质含氮量会影响红曲霉固态发酵过程中菌丝体量的积累,从而影响次级代谢产物的产量。

Effects of Two Auxiliary Substrates on Yield of Monacolin K and Monascus Pigments in Solid-State Fermentation of Red Yeast Rice

Monascus spp. produces various secondary metabolites such as Monacolin K (MK) and Monascus pigments (MPs) during fermentation which were beneficial to human. In order to obtain a certain amount of MK and MPs at the same time, the solid-state fermentation (SSF) of Monascus MPs-7 on the rice substrate with the addition of different concentrations of soybean meal and soybean dregs was explored. The yield of the two metabolites were analyzed, and the influence mechanism of auxiliary material was also explored. The results showed that adding two kinds of auxiliary material as fermentation medium promoted the yield of MK. However, the yield of MPs was inhibited. When soybean meal addition was 15% (mass fraction), the production capacity of MK was the highest, but almost no MPs was produced. Addition of 15%(mass fraction) bean dregs as fermentation medium increased the yield of MK and in the meanwhile maintained a certain yield of MPs, and the cost was lower than that of soybean meal, which was more suitable as an auxiliary material added to the SSF of Monascus. The study showed that nitrogen content of the substrate could affect the accumulation of mycelium during the SSF of Monascus, thus affecting the production of secondary metabolites.