Guangdong Provincial Key Laboratory of Fermentation and Enzyme Engineering, School of Bioscience and Bioengineering, South China University of Technology , Guangzhou 510006, People's Republic of China.
School of Energy and Environment, City University of Hong Kong , Tat Chee Avenue, Kowloon, Hong Kong, People's Republic of China.
J Agric Food Chem. 2017 May 24;65(20):4133-4139. doi: 10.1021/acs.jafc.7b00519. Epub 2017 May 12.
Succinate dehydrogenase inactivation in Yarrowia lipolytica has been demonstrated for robust succinic acid production, whereas the inefficient glucose metabolism has hindered its practical application. In this study, a simple and efficient adaptive evolution strategy via cell immobilization was conducted in shake flasks, with an aim to restore the glucose metabolism of Y. lipolytica mutant PGC01003. After 21 days with 14 generations evolution, glucose consumption rate increased to 0.30 g/L/h in YPD medium consisting of 150 g/L initial glucose concentration, while poor yeast growth was observed in the same medium using the initial strain without adaptive evolution. Succinic acid productivity of the evolved strain also increased by 2.3-fold, with stable cell growth in YPD medium with high initial glucose concentration. Batch fermentations resulted in final succinic acid concentrations of 65.7 g/L and 87.9 g/L succinic acid using YPD medium and food waste hydrolysate, respectively. The experimental results in this study show that a simple and efficient strategy could facilitate the glucose uptake rate in succinic acid fermentation using glucose-rich substrates.
已证明在解脂耶氏酵母中琥珀酸脱氢酶失活有利于生成大量琥珀酸，然而其葡萄糖代谢效率低下阻碍了其实际应用。在本研究中，通过细胞固定化在摇瓶中进行了一种简单高效的适应性进化策略，旨在恢复解脂耶氏酵母突变株 PGC01003 的葡萄糖代谢。经过 21 天 14 代进化，在初始葡萄糖浓度为 150 g/L 的 YPD 培养基中，葡萄糖消耗率提高到 0.30 g/L/h，而在相同的初始菌株没有经过适应性进化的培养基中观察到酵母生长不良。进化菌株的琥珀酸生产力也提高了 2.3 倍，在高初始葡萄糖浓度的 YPD 培养基中保持稳定的细胞生长。分批发酵分别使用 YPD 培养基和食物废物水解物，得到最终琥珀酸浓度为 65.7 g/L 和 87.9 g/L。本研究的实验结果表明，使用富含葡萄糖的底物进行琥珀酸发酵时，这种简单高效的策略可以提高葡萄糖摄取率。
