法夫酵母中产类胡萝卜素特性与其合成相关基因表达关系的研究

The Relationship Between Characteristics of Yielding Carotenoid and Expression of Carotenogenic Genes in Phaffia rhodozyma

为研究法夫酵母中类胡萝卜素合成代谢调控机理,通过高效液相色谱法和实时定量PCR技术分别对JMU-VDL668和JMU-N3法夫酵母菌株中类胡萝卜素和类胡萝卜素合成相关基因的表达差异进行分析,并研究了在JMU-VDL668菌株培养过程中添加β-胡萝卜素对其产虾青素的影响。结果显示,法夫酵母类胡萝卜素代谢途径的关键酶crt E,crt YB,crt I和crt S基因在JMUVDL668菌株中的表达水平整体低于JMU-N3菌株,而JMU-N3菌株中没有检测到crt R基因的表达。在JMU-VDL668菌株培养过程中添加β-胡萝卜素发现,在72 h和96 h添加时能促进虾青素的合成,其中96 h添加时所得虾青素比对照组提高了83%。结果表明,这两株菌的产类胡萝卜素特性与类胡萝卜素合成相关基因的表达量存在一定的正相关关系,且JMU-VDL668菌株中总类胡萝卜素细胞产率在一定范围内,可能存在反馈调节机制。

In order to study the metabolic regulation mechanism of carotenoid synthesis in Phaffia rhodozyma, the carotenoid biosynthesis characteristics and the expression differences of carotenogenic genes in different strains of P. rhodozyma, JMU-VDL668 and JMU-N3 were analyzed by HPLC and real-time q PCR, respectively. The effects of adding β-carotene during the culture of strain JMU-VDL668 to the yield of astaxanthin were also analyzed. The results showed that, the expression levels of the carotenogenic genes crt E, crt I, crt YB and crt S of key enzymes in the metabolic pathway of carotenoid in P. rhodozyma were lower in JMU-VDL668 than JMU-N3, even the expression of crt R was not detected in JMU-N3. The synthesis of astaxanthin increased when β-carotene was added at 72 h and 96 h of culturing JMU-VDL668, and the astaxanthin increased 83% while adding β-carotene at 96 h compared to the control group. The results indicated that the characteristics of yielding carotenoid was positively correlated to the expression level of carotenogenic genes. Moreover, the productivity of cells for total carotenoid in JMU-VDL668 was in a certain range, suggesting that there was a feedback regulation.