A complete industrial system for economical succinic acid production by Actinobacillus succinogenes

An industrial fermentation system using lignocellulosic hydrolysate, waste yeast hydrolysate, and mixed alkali to achieve high-yield, economical succinic acid production by Actinobacillus succinogenes was developed. Lignocellulosic hydrolysate and waste yeast hydrolysate were used efficiently as carbon sources and nitrogen source instead of the expensive glucose and yeast extract. Moreover, as a novel method for regulating pH mixed alkalis (Mg(OH)₂ and NaOH) were first used to replace the expensive MgCO₃ for succinic acid production. Using the three aforementioned substitutions, the total fermentation cost decreased by 55.9%, and 56.4g/L succinic acid with yield of 0.73g/g was obtained, which are almost the same production level as fermentation with glucose, yeast extract and MgCO₃. Therefore, the cheap carbon and nitrogen sources, as well as the mixed alkaline neutralize could be efficiently used instead of expensive composition for industrial succinic acid production.