Adaptive evolution of Clostridium butyricum and scale-Up for high-Concentration 1,3-propanediol production

In order to obtain the excellent 1,3-propanediol (1,3-PDO) producer from wild-type Clostridium butyricum, adaptive evolution was carried out to select the strain for fast growth. The most significant change was that fermentation time decreased from 36 h to 20 h after adaptive evolution. Thus, it led to the corresponding volumetric productivity of 1,3-PDO increasing from 0.97 to 2.14 (g/L·h⁻¹) which increased by 114%. Adaptive evolution was also applied to butyric acid tolerant strain selected based on the fast-growing one through a simple equipment. 1,3-PDO concentration increased from 40.28 to 66.23 g/L through fed-batch fermentation by butyric acid tolerant strain compared with the fast-growing one. In addition, the endpoint strain was successfully and steadily used in the 50-L scale fermentation. Thus, adaptive evolution is an excellent strategy which can help us select the fast-growing strain and reduce the negative effect from substrate and metabolite inhibition. © 2018 American Institute of Chemical Engineers AIChE J, 65: 32–39, 2019