Zhang Chan, Liang Jian, Yang Le, Chai Shiyuan, Zhang Chenxi, Sun Baoguo, Wang Chengtao
Beijing Advanced Innovation Center for Food Nutrition and Human Health, Beijing Technology & Business University (BTBU), Beijing, 100048, China.
School of Food and Chemical Engineering, Beijing Technology & Business University, Beijing, 100048, China.
AMB Express. 2017 Dec;7(1):22. doi: 10.1186/s13568-016-0311-z. Epub 2017 Jan 10.
This study investigated the effects of glutamic acid on production of monacolin K and expression of the monacolin K biosynthetic gene cluster. When Monascus M1 was grown in glutamic medium instead of in the original medium, monacolin K production increased from 48.4 to 215.4 mg l, monacolin K production increased by 3.5 times. Glutamic acid enhanced monacolin K production by upregulating the expression of mokB-mokI; on day 8, the expression level of mokA tended to decrease by Reverse Transcription-polymerase Chain Reaction. Our findings demonstrated that mokA was not a key gene responsible for the quantity of monacolin K production in the presence of glutamic acid. Observation of Monascus mycelium morphology using Scanning Electron Microscope showed glutamic acid significantly increased the content of Monascus mycelium, altered the permeability of Monascus mycelium, enhanced secretion of monacolin K from the cell, and reduced the monacolin K content in Monascus mycelium, thereby enhancing monacolin K production.
本研究考察了谷氨酸对莫纳可林K产量及莫纳可林K生物合成基因簇表达的影响。当红曲霉菌株M1在谷氨酸培养基而非原始培养基中生长时，莫纳可林K产量从48.4 mg/L增加至215.4 mg/L，产量提高了3.5倍。谷氨酸通过上调mokB - mokI的表达来提高莫纳可林K的产量；在第8天，通过逆转录-聚合酶链反应发现mokA的表达水平有下降趋势。我们的研究结果表明，在谷氨酸存在的情况下，mokA不是影响莫纳可林K产量的关键基因。利用扫描电子显微镜观察红曲霉菌丝体形态发现，谷氨酸显著增加了红曲霉菌丝体的含量，改变了红曲霉菌丝体的通透性，增强了莫纳可林K从细胞中的分泌，并降低了红曲霉菌丝体中莫纳可林K的含量，从而提高了莫纳可林K的产量。
