Research on L-phenyllactic acid and its process
L-苯基乳酸的L-苯基乳酸及其工艺研究

摘要

L-苯基乳酸（L-phenyllactic acid, PLA）是一种具有广谱抗菌作用的天然小分子有机酸，近年来在食品防腐和生物制药等领域显示出广阔的应用前景。其生物合成及其工艺研究主要集中在微生物发酵和全细胞催化策略上，但是其产量和纯度难以满足工业生产的需求。本文利用基因工程技术，构建了L-苯基乳酸合成途径的关键酶基因（lacI和 lacS），并将其成功地应用于L-苯基乳酸的生物合成，为实现工业化生产奠定了基础。通过对关键酶基因进行 PCR扩增，并将其与质粒pCAPTX-based融合表达，构建了高效的重组质粒pCAPTX-based，并将其成功地导入菌株YF11中。实验结果表明，重组菌株YF11能够在4℃条件下发酵96h，发酵液中L-苯基乳酸的产量为0.91g/L。利用该工程菌株实现了L-苯基乳酸的产业化生产，并对其工业化生产工艺进行了初步探讨。

Abstract

L-phenyllactic acid (PLA) is a natural small-molecule organic acid with broad-spectrum antibacterial effects. In recent years, it has shown broad application prospects in the fields of food preservatives and biopharmaceuticals. Its biosynthesis and process research mainly focus on microbial fermentation and whole-cell catalysis strategies, but its yield and purity are difficult to meet the needs of industrial production. This article used genetic engineering technology to construct the key enzyme genes (lacI and lacS) of the L-phenyllactic acid synthesis pathway and successfully applied them to the biosynthesis of L-phenyllactic acid, laying the foundation for industrialized production. By PCR amplifying the key enzyme gene and fusion expression with the plasmid pCAPTX-based, an efficient recombinant plasmid pCAPTX-based was constructed and successfully introduced into strain YF11. Experimental results show that the recombinant strain YF11 can ferment for 96 hours at 4°C, and the production of L-phenyl lactic acid in the fermentation broth is 0.91g/L. This engineering strain was used to realize the industrial production of L-phenyl lactic acid, and its industrial production process was initially discussed.