酿酒酵母工程菌高密度培养生产香紫苏醇

High cell density culture of an engineered yeast strain for sclareol production

为提高酿酒酵母工程菌S7香紫苏醇产量,采用摇瓶培养,研究了其生长和代谢特点,发现产物合成与菌体生长密切关联。在3 L发酵罐中通过补料-溶氧联动控制的方式,以葡萄糖、乙醇和葡萄糖/乙醇混合物为碳源进行高密度培养,香紫苏醇产量分别达到253 mg/L、386 mg/L和408 mg/L,最高产量是摇瓶培养的27倍。说明添加乙醇作为碳源有助于香紫苏醇合成。研究结果对优化酿酒酵母细胞工厂,高效生产萜类化合物具有重要参考价值。

Cell growth profiles were evaluated in shake-flask culture to improve sclareol production by the engineered yeast strain Saccharomyces cerevisiae S7. Product formation was tightly coupled with cell growth. High cell density cultures were performed with different carbon sources using a dissolved oxygen level feedback-control strategy in a 3 L bioreactor. The titers of sclareol were 253 mg/L, 386 mg/L and 408 mg/L, respectively, when glucose, ethanol and glucose/ethanol mixture were used as the carbons sources. The maximal titer was 27-fold higher than that obtained under shake-flask culture conditions. The results suggested that the presence of ethanol was beneficial to sclareol production. These results provided useful information for optimization of yeast cell factory and efficient production of terpenoids.