Feasibility for producing succinic acid by fermentation of cornhusk dilute acid hydrolysate after detoxification

Succinic acid is an important C4 platform chemical. Utilization of non-food biomass instead of starch for succinic acid production by fermentation does not threaten grain provisionment and can reduce the cost of substrate. Cornhusk is a kind of non-food and low-cost biomass. Cornhusk was hydrolyzed by dilute acid in this research. Optimized technical conditions for detoxification of cornhusk dilute acid hydrolysate were determined by experiments: activated carbon 1%(W/V), pH4.0, temperature 30°C, detoxification time 30min. The decoloration ratio of cornhusk hydrolysate was 92.27%. 75% of furfurol, 53% of 5-hydroxymethyl furfural and 98% of polyphenol compounds were removed, and the loss of total sugar was below 5%. In batch cultures, glucose, xylose and arabinose in cornhusk dilute acid hydrolysate after detoxification were consumed by Actinobacillus succinogenes NJ113, when the total sugar concentration was 50 g/L in medium, the final succinic acid concentration of 34.2 g/L was obtained, resulting in a succinic acid yield of 0.68 g/g and a succinic acid productivity of 0.83 g/(L · h). When the total sugar concentration was 68.2 g/L in medium, the succinic acid concentration was 42.3g/L, the yield was 0.62g/g, and productivity was 0.98 g/(L · h). The cornhusk dilute acid hydrolysate after detoxification can be the substitution of glucose as a carbon source for producing succinic acid by anaerobic fermentation.