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

Abstract

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/LÁh −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. (a) the morphology of Clostridium butyricum in the initial stage of Gen 0 adaptive evolution process. (b) The morphology of Clostridium butyricum in the last stage of Gen 0 adaptive evolution process. (c) The effect of 5 g/L butyric acid and acetic acid to the growth of Gen 4 strain. (d) Different growing status of Gen 0, Gen 1, Gen 2, Gen 3, and Gen 4 strain in seed culture contained 70 g/L glycerol. The "XMU" were written on the back of the each bottles. [Color figure can be viewed at wileyonlinelibrary.com] Figure 5. Time course of Gen 7 strain fermentation on 50-L scale. (a, b) Represent the concentrations of glycerol, 1,3-PDO (g/L), acids and OD in batch and fed-batch fermentation process.[Color figure can be viewed at wileyonlinelibrary.com]

A robust soft sensor to monitor 1,3‐propanediol fermentation process by Clostridium butyricum based on artificial neural network

“…The data of C. butyricum H304 (Strain II) fermentation process in our previous work (Zhang, Huang et al, 2019) was reanalyzed. The medium was prepared as described in our previous work (Zhang, Zhuang et al, 2019; Zhu & Fang, 2013). The RCM medium contained (g/L): beef extract 10; peptone 10; yeast extract 3; glucose 5; soluble starch 1; NaCl 3; CH 3 COONa 3; and cysteine hydrochloride 0.5.…”

“…The culture conditions were as described in our previous work with few modifications (Zhang, Zhuang et al, 2019; Zhu & Fang, 2013). 10% (v/v) of strain which was stored at 4°C was revived in anaerobic serum bottles containing 50 ml of RCM medium.…”

“…The concentrations of 1,3‐PDO and glycerol were determined according to our previous work by high‐performance liquid chromatography (Agilent 1100) on an Aminex HPX‐87H column (300 mm × 7.8 mm; Bio‐Rad, CA) with a refractive index detector. Operating conditions were as follows: sample volume 20 μl; mobile phase 0.5 mmol/L H 2 SO 4 ; flow rate 0.5 ml/min; column temperature 60°C; detector temperature 45°C (Zhang, Zhuang et al, 2019; Zhu & Fang, 2013).…”

A novel kinetic model to describe 1,3‐propanediol production fermentation by Clostridium butyricum

“…The medium was performed according to our previous work. 3,24 The RCM medium contained (g/L): peptone 10; beef extract 10; soluble starch 1; glucose 5; yeast extract 3; NaCl 3; cysteine hydrochloride 0.…”

“…The culture conditions were according to our previous work with some modifications. 3,24 Ten percent (vol/vol) of strain that was stored at 4 C was revivified in anaerobic serum bottles containing 50 ml RCM medium. The culture was grown for 18-24 hr at 37 C shaking at 150 rpm.…”