氨基酸对紫红曲霉Y66中红曲色素合成影响的研究

Effect of amino acids on monascus pigments biosynthesis in Monacus purpureus Y66

利用含无氨基氮源的合成培养基发酵试验研究了20种常见氨基酸分别对紫红曲霉(Monascus purpureus)Y66中红曲色素合成的影响。研究结果表明:当游离氨基酸添加量为5 g/L时,组氨酸的添加能够促进红色素的合成,酪氨酸的添加有利于黄色素的合成,而异亮氨酸、蛋氨酸的添加使红色素和黄色素的合成均受到显著抑制,其余氨基酸对色素合成则表现出不同程度的抑制或者无显著影响。氨基酸浓度梯度试验结果表明,当组氨酸添加量为7 g/L时,对红色素合成的增强作用最显著,其峰值产量提高了32.7%;当酪氨酸添加量为7 g/L时,对黄色素合成的增强作用最显著,其峰值产量提高了24.8%。综上所述,在培养基中分别添加7g/L组氨酸或酪氨酸能够显著提高紫红曲霉Y66中红曲色素的产量。研究结果将为探究红曲色素合成机制以及构建红曲色素的高产发酵体系提供有益借鉴。

The effect of 20 different amino acids on monascus pigments biosynthesis in M.. purpureus Y66 was systematically investigated by fermentation experiments using chemical synthetic fermentation media containing the nitrogen source without amino acids. When 5 g/L of amino acids were added, histidine promoted the red pigment production and tyrosine improved the yellow pigment yield ; on the contrary, isoleucine and methionine both significantly inhibited the red and yellow pigments biosynthesis. The rest amino acids showed a slight inhibition effect or no obvious influence on the pigment biosynthesis. Moreover, the effect of different concentration gradient addition of 2 amino acids （histidine and tyrosine） on pigments production was further analyzed. The results demonstrated that addition of 7 g/L histidine had the most significant enhancement effect on the red pigment production, the outputwas increased by 32.7% ; and addition of 7 g/L tyrosine led to the highest increase in the yellow pigment biosynthesis output by 24.8%. In conclusion, adding 7 g/L of histidine or tyrosine into the chemical synthetic fermentation media could significantly boost the pigments production in M. purpureus Y66. This study would provide an insight into the monascus pigments biosynthesis mechanism and benefit for constructing the high yield fermentation system for the monascus pigments production.