Zhang De-Huai, Jiang Lu-Xi, Li Na, Yu Xuya, Zhao Peng, Li Tao, Xu Jun-Wei
Faculty of Life Science and Technology, Kunming University of Science and Technology , Kunming, 650500, China.
Faculty of Science, Kunming University of Science and Technology , Kunming, 650500, China.
J Agric Food Chem. 2017 Jun 14;65(23):4683-4690. doi: 10.1021/acs.jafc.7b00629. Epub 2017 May 30.
The squalene epoxidase (SE) gene from the biosynthetic pathway of ganoderic acid (GA) was cloned and overexpressed in Ganoderma lingzhi. The strain that overexpressed the SE produced approximately 2 times more GA molecules than the wild-type (WT) strain. Moreover, SE overexpression upregulated lanosterol synthase gene expression in the biosynthetic pathway. These results indicated that SE stimulates GA accumulation. Then, the SE and 3-hydroxy-3-methylglutaryl coenzyme A (HMGR) genes were simultaneously overexpressed in G. lingzhi. Compared with the individual overexpression of SE or HMGR, the combined overexpression of the two genes further enhanced individual GA production. The overexpressing strain produced maximum GA-T, GA-S, GA-Mk, and GA-Me contents of 90.4 ± 7.5, 35.9 ± 5.4, 6.2 ± 0.5, and 61.8 ± 5.8 μg/100 mg dry weight, respectively. These values were 5.9, 4.5, 2.4, and 5.8 times higher than those produced by the WT strain. This is the first example of the successful manipulation of multiple biosynthetic genes to improve GA content in G. lingzhi.
从灵芝酸（GA）生物合成途径中克隆了角鲨烯环氧酶（SE）基因，并在灵芝中进行了过表达。过表达SE的菌株产生的GA分子比野生型（WT）菌株多约2倍。此外，SE过表达上调了生物合成途径中羊毛甾醇合酶基因的表达。这些结果表明SE刺激GA积累。然后，在灵芝中同时过表达SE和3-羟基-3-甲基戊二酰辅酶A（HMGR）基因。与单独过表达SE或HMGR相比，两个基因的联合过表达进一步提高了GA的产量。过表达菌株产生的GA-T、GA-S、GA-Mk和GA-Me的最大含量分别为90.4±7.5、35.9±5.4、6.2±0.5和61.8±5.8μg/100mg干重。这些值分别比WT菌株产生的值高5.9、4.5、2.4和5.8倍。这是成功操纵多个生物合成基因以提高灵芝中GA含量的首个实例。
