Key Laboratory of Food and Biotechnology of Suzhou, Changshu Institute of Technology, Changshu 215500, China.
Institute of Basic Medical and Biological Sciences, Soochow University, Suzhou 215000, China.
J Zhejiang Univ Sci B. 2018;19(4):285-292. doi: 10.1631/jzus.B1700040.
(R)-2-hydroxy-3-phenylpropionic acid (PLA) is an ideal antimicrobial compound with broad-spectrum activity against a wide range of Gram-positive bacteria, some Gram-negative bacteria, and fungi. We studied the bioconversion of phenylpyruvate (PPA) to PLA using whole recombinant Escherichia coli cells in a series of buffer/organic solvent systems. Octane was found to be the best organic solvent. The optimum volume ratio of the water phase to the n-octane phase, conversion temperature, substrate concentration, and cell concentration were 6:4, 40 °C, 12.5 g/L, and 30 g/L wet cells, respectively. Under the optimized conditions, the average PLA productivity in the aqueous/ n-octane system was 30.69% higher than that in the aqueous system, and 32.31 g/L PLA was obtained with the use of a stirred reactor (2-L scale). Taken together, our findings indicated that PLA biosynthesis was more efficient in an aqueous/n-octane biphasic system than in a monophasic aqueous system. The proposed biphasic system is an effective strategy for enhancing PLA yield and the biosynthesis of its analogues.
(R)-2-羟基-3-苯基丙酸（PLA）是一种理想的抗菌化合物，对广泛的革兰氏阳性菌、一些革兰氏阴性菌和真菌具有广谱活性。我们使用一系列缓冲/有机溶剂系统中的全重组大肠杆菌细胞研究了苯丙酮酸（PPA）到 PLA 的生物转化。己烷被发现是最好的有机溶剂。水相和正己烷相的最佳体积比、转化温度、底物浓度和细胞浓度分别为 6:4、40°C、12.5g/L 和 30g/L 湿细胞。在优化条件下，水/正己烷体系中的 PLA 平均产率比水相体系高 30.69%，使用搅拌式反应器（2-L 规模）可获得 32.31g/L 的 PLA。总之，我们的研究结果表明，PLA 生物合成在水/正己烷两相体系中比单相水体系更有效。所提出的两相体系是提高 PLA 产量和类似物生物合成的有效策略。
