不同单色光对紫色红曲霉生长、色素和桔霉素合成的影响

Effects of Different Monochromatic Light on Growth, Pigments and Citrinin Biosynthesis of Monascus purpureus

以紫色红曲霉M9为研究对象,研究不同单色光对其生长、色素和桔霉素合成的影响。采用观察法和高效液相色谱法对紫色红曲霉M9在持续红光、黄光、绿光、蓝光照射下的菌落形态及6种红曲色素产量进行研究。采用高效液相色谱法和RT-qPCR法对不同红光光照时间和光照强度下红曲色素和桔霉素产量以及相关基因表达量进行测定。结果表明,红光是最显著的促进紫色红曲霉M9生长和色素产生的光源。高产红曲色素、低产桔霉素的最佳光照时间和强度分别为30 min/d和300 lx,初步推测红曲色素合成相关基因mppA/B/D/F、mppR1/R2、MpPKS5、MpFasA2/B2可能参与两种橙色素的生物合成,mppC、mppE可能参与两种红色素和两种黄色素的生物合成;桔霉素合成相关基因ctnA/D/E/F/G/H/I、orf1/3/4/5、pksCT可能参与桔霉素的合成代谢,而ctnR1可能参与桔霉素的分解代谢。

Effects of different monochromatic lights(red, yellow, green and blue) on culture morphology and six well known pigments production of Monascus purpureus M9 were investigated in this study. Furthermore, various red light intensities and illumination time on six well known pigments, citrinin production and expression levels of monascus pigments and citrinin biosynthetic gene cluster were examined using HPLC and RT-qPCR. The results showed that red light had the mostly significant effects on the growth and pigments production of Monascus purpureus M9. The optimal illumination time and illumination intensity were 30 min/d and 300 lx. The expression levels of biosynthetic genes, such as mppA/B/D/F, mppR1/R2, MpPKS5, and MpFasA2/B2 were positively correlated with the production of orange pigments, and the expression levels of mppC and mppE were positively correlated with the yields of red and yellow pigments. Moreover, ctnA/D/E/F/G/H/I, orf1/3/4/5, pksCT were positively correlated with citrinin production and ctnR1 was negatively correlated with citrinin production.