增强甘油代谢提高酵母工程菌的红没药烯产量

Enhancing the glycerol utilization of engineered yeast increases its bisabolene production

摘要:

红没药烯(bisabolene)是植物精油中普遍存在的活性成分，广泛应用于化工、医药、保健等领域。本研究通过对酿酒酵母(Saccharomyces cerevisiae)工程菌中甘油代谢途径进行改造，从而获得高产红没药烯的酵母工程菌株。以利用GAL启动子加强甲羟戊酸途径的酿酒酵母工程菌YS036作为出发菌株，通过高表达来自嗜鞣管囊酵母(Pachysolen tannophilus)的甘油转运通道基因PtFPS2和来自耐热甲基化酵母(Ogataea parapolymorpha)的甘油脱氢酶基因Opgdh，有效增强酵母对甘油的利用；另一方面，为减弱葡萄糖阻遏作用，敲除葡萄糖抑制转录因子编码基因MIG1。结果表明，MIG1敲除菌的蔗糖和甘油共利用能力得到进一步增强，重组菌株的GAL启动子转录水平增加。在摇瓶发酵中的红没药烯的最高产量比出发菌株提高82.2%，达到866.7 mg/L。本研究通过对酵母工程菌碳源代谢进行改造，提高了红没药烯的产量，并为提高工程酵母合成其他萜类化合物产量提供了一种有效的策略。

Abstract:

Bisabolene is a compound commonly found in essential oils of various plants. It has a broad application in sectors such as chemical, pharmaceutical, and health-care products. This study focuses on modifying the glycerol metabolism pathway to obtain a high bisabolene-producing strain of Saccharomyces cerevisiae. To achieve this, the glycerol transporter gene PtFPS2 from Pachysolen tannophilus and the glycerol dehydrogenase gene Opgdh from Ogataea parapolymorpha were overexpressed in engineered yeast YS036, which was equipped with a GAL promoters-enhanced mevalonic acid pathway. Additionally, the glucose-inhibiting transcription factor MIG1 was knocked out to reduce glucose inhibition. The results showed that the GAL promoter transcription levels of the recombinant yeast strains increased, and the co-utilization of sucrose and glycerol was further improved in MIG1-knockout strain. Moreover, the maximum yield of bisabolene in shaking flask fermentation increased to 866.7 mg/L, an 82.2% increase compared to that of the original strain. By modifying the metabolic pathway of carbon sources, the yield of bisabolene was considerably improved. This study offers an effective strategy for enhancing the yield of terpene compounds in engineered yeast.