(R)-Mandelic acid (R-MA) is a key precursor for the synthesis of semi-synthetic penicillin, cephalosporin, anti-obesity drugs, antitumor agents, and chiral resolving agents for the resolution of racemic alcohols and amines. In this study, an enzymatic method for the large-scale production of R-MA by a stereospecific nitrilase in an aqueous system was developed. The nitrilase activity of the Escherichia coli BL21(DE3)/pET-Nit whole cells reached 138.6 U/g in a 20,000-L fermentor. Using recombinant E. coli cells as catalyst, 500 mM R,S-mandelonitrile (R,S-MN) was resolved into 426 mM (64.85 g/L) R-MA within 8 h, and the enantiomeric excess (ee) value of R-MA reached 99%. During the purification process, pure R-MA with a recovery rate of 78.8% was obtained after concentration and crystallization. This study paved the foundation for the upscale production of R-MA using E. coli whole cells as biocatalyst.

（R）-扁桃酸（R- MA）是用于合成半合成青霉素，头孢菌素，抗肥胖药，抗肿瘤剂和手性拆分剂的重要前体，用于拆分外消旋醇和胺。在这项研究中，开发了一种酶促方法，用于在水性体系中通过立体特异性腈水解酶大规模生产R -MA。在20,000 L的发酵罐中，大肠杆菌BL21（DE3）/ pET-Nit全细胞的腈水解酶活性达到138.6 U / g。使用重组大肠杆菌细胞作为催化剂，将500 mM R，S-扁桃腈（R，S -MN）分解为426 mM（64.85 g / L）R-MA在8小时内，R -MA的对映体过量（ee）值达到99％。在纯化过程中，浓缩和结晶后获得纯净的R -MA，回收率为78.8％。该研究为使用大肠杆菌全细胞作为生物催化剂大规模生产R -MA奠定了基础。