State Key Laboratory of Microbial Metabolism, Shanghai Jiao Tong University, 800 Dong-Chuan Road, Shanghai 200240, China.
Bioresour Technol. 2011 Sep;102(17):8185-90. doi: 10.1016/j.biortech.2011.06.043. Epub 2011 Jun 26.
The effect of nitrogen limitation on the production of the antitumor compounds, ganoderic acids (GAs), by Ganoderma lucidum and on transcription levels of triterpene biosynthesis genes in this mushroom was investigated. At 3mM glutamine, a maximal content of GA-Mk, GA-T, GA-S, and GA-Me was 2.16, 11.76, 31.09, and 7.04 μg/mg cell dry weight, respectively, which was 2.8-, 5.8-, 8.3-, and 5.1-fold that obtained at 60mM glutamine. The transcription levels of biosynthetic genes encoding 3-hydroxy-3-methylglutaryl-CoA reductase, farnesyl pyrophosphate synthase, squalene synthase, lanosterol synthase, and a putative nitrogen regulator, AreA, were up-regulated by 37-, 18-, 4.5-, 3.2-, and 13-fold, respectively, in nitrogen limitation conditions, suggesting that increased GAs biosynthesis may result from higher expression of those genes. This study demonstrated a useful strategy for enhancing GAs production and provided useful information for further investigation on its biosynthesis regulation.
研究了氮限制对灵芝产生抗肿瘤化合物——灵芝酸（GAs）的影响，以及对这种蘑菇中三萜类生物合成基因转录水平的影响。在 3mM 谷氨酰胺的条件下，GA-Mk、GA-T、GA-S 和 GA-Me 的最大含量分别为 2.16、11.76、31.09 和 7.04μg/mg 细胞干重，分别是 60mM 谷氨酰胺条件下的 2.8、5.8、8.3 和 5.1 倍。在氮限制条件下，编码 3-羟基-3-甲基戊二酰辅酶 A 还原酶、法呢基焦磷酸合酶、鲨烯合酶、羊毛甾醇合酶和一个假定的氮调控因子 AreA 的生物合成基因的转录水平分别上调了 37、18、4.5、3.2 和 13 倍，这表明 GAs 生物合成的增加可能是由于这些基因的高表达所致。本研究为提高 GAs 的产量提供了一种有效的策略，并为进一步研究其生物合成调控提供了有用的信息。
