(191ac) Effects of Artificial Electron Carriers on High-Efficient Butyric Acid Production through Co-Fermentation of Glucose and Acetate By Clostridium Tyrobutyricum
AIChE Annual Meeting
2018
2018 AIChE Annual Meeting
Food, Pharmaceutical & Bioengineering Division
Poster Session: Food and Bioprocess Engineering
Monday, October 29, 2018 - 3:30pm to 5:00pm
The addition of acetate into Clostridial Growth Medium during glucose fermentation (at 24 h) was found to inhibit acetate formation and increase the final titer and productivity of butyrate by Clostridium tyrobutyricum. However, only limited (0.79-7.62 g/L) acetate was utilized. In order to strengthen the acetate re-assimilation, artificial electron carrier (methyl viologen, benzyl viologen or neutral red) was also introduced into the medium to increase the NADH supply which facilitated the acetate utilization. As expected, more acetate was utilized (4.9-20.3 g/L) and enhanced butyric acid fermentation was achieved. Subsequently, the effect of acetate and glucose co-fermentation with benzyl viologen addition was studied in bioreactor. Compared with the control, when 13.4 g/L acetate and 3.75 μM BV were added into the medium at 27 h, the final concentration, productivity and yield of butyrate increased by 40.5% (from 39.8 to 55.9 g/L), 10.0% (from 0.69 to 0.76 g/L/h) and 32.3% (from 0.31 to 0.41 g/g carbon source), receptivity. In addition, the selectivity of butyrate exhibited a sharp increase from 78% to 97.4%. Therefore, the proposed strategy can be used to obtain high-efficient butyric acid production. Furthermore, acetic acid in-suit detoxification which enables commercial utilization of lignocellulosic biomass hydrolyzates could be achieved by artificial electron carrier addition.