The present study describes the use of metabolic engineering to achieve the production of R,R-2,3-butanediol (R,R-2,3-BD) of ultra-high optical purity (> 99.99%). To this end, the diacetyl reductase (DAR) gene (dud A) of Paenibacillus polymyxa ZJ-9 was knocked out via homologous recombination between the genome and the previously constructed targeting vector pRN5101-L′C in a process based on homologous single-crossover. PCR verification confirmed the successful isolation of the dud A gene disruption mutant P. polymyxa ZJ-9-△dud A. Moreover, fermentation results indicated that the optical purity of R,R-2,3-BD increased from about 98% to over 99.99%, with a titer of 21.62 g/L in Erlenmeyer flasks. The latter was further increased to 25.88 g/L by fed-batch fermentation in a 5-L bioreactor.

本研究描述了利用代谢工程技术实现超高光学纯度（> 99.99％）的R，R -2,3-丁二醇（R，R -2,3-BD）的生产。为此，在基于同源单交换的过程中，通过基因组与先前构建的靶向载体pRN5101-L'C之间的同源重组敲除多粘芽孢杆菌ZJ-9的二乙酰还原酶（DAR）基因（dud A）。。PCR验证证实成功分离了dud A基因破坏突变体多粘菌P. polymyxa ZJ-9-△ dudA。此外，发酵结果表明R，R的光学纯度-2,3-BD从约98％增至99.99％以上，在锥形瓶中的滴度为21.62 g / L。通过在5-L生物反应器中分批补料发酵将后者进一步提高至25.88 g / L。