不产桔霉素高产红曲色素的基因工程红曲菌株构建

以一株高产红曲色素的紫色红曲菌（Monascus purpureus）J01为研究对象，采用根癌农杆菌（Agrobacterium tumefaciens）介导 的T-DNA转化技术，敲除紫色红曲菌株J01基因组中的桔霉素合成关键基因pksCT，构建一株不产桔霉素高产红曲色素的红曲菌株。 结果表明，通过菌落形态观察和生物量测定得出，菌株J42与菌株J01的菌落形态及生物量无显著性差异（P＞0.05）；经高效液相色谱（HPLC）与液相色谱串联质谱（LC-MS/MS）分析得出，菌株J01的桔霉素含量为5.1mg/kg，pksCT基因敲除菌株J42菌丝体中未检测到 桔霉素；菌株J42的黄色素，橙色素和红色素色价分别为1 877 U/g、773 U/g、1 068 U/g，显著高于菌株J01（P＜0.01），并且菌株J42的红 曲色素总色价为415 U/mL，是原始菌株的1.56倍，成功构建了一株不产桔霉素高产红曲色素的生产菌株J42。

Construction of genetically engineered Monascus strains with no citrinin yield but high yield Monascus pigments

Using Monascus purpureus J01 with high yield Monascus pigments as research object, the Agrobacterium tumefaciens-mediated transfer deoxyribonucleic acid (T-DNA) transformation technique was adopted, the key gene pksCT in citrinin biosynthesis was knocked out, and a Monascus strain with no citrinin yield but high yield Monascus pigments was constructed. By colony morphology observation and biomass determination, the results showed that there was no significant difference between strain J42 and J01 (P＞0.05) in colony morphology and biomass. The citrinin content of strain J01 was 5.1 mg/kg, and no citrinin was detected in the mycelium of strain J42 by HPLC and LC-MS/MS. The color value of yellow pig- ments, orange pigments and red pigments of strain J42 was 1 877 U/g, 773 U/g and 1 068 U/g, respectively, which was significantly higher than strain J01 (P＜0.01). At the same time, the total color value of Monascus pigments of strain J42 was 415 U/ml, which was 1.56 times that of the original strain. Therefore, a strain of J42, with no citrinin yield but high yield Monascus pigments was constructed.