Enhanced butanol fermentation using metabolically engineered Clostridium acetobutylicum with ex situ recovery of butanol. (October 2016)

• Record Type: Journal Article
• Authors: Lee, Sang-Hyun; Kim, Sooah; Kim, Jung Yeon; Cheong, Nam Yong; Kim, Kyoung Heon
• Is Part Of: Bioresource technology. Volume 218(2016)
• Page Start: 909
• Page End: 917
• Publication Date: 2016-10
• Subjects: Acetone-butanol-ethanol fermentation -- Clostridium acetobutylicum -- Coenzyme A -- Intracellular metabolite analysis -- Metabolic engineering; Biomass -- Periodicals; Biomass energy -- Periodicals; Bioremediation -- Periodicals; Agricultural wastes -- Periodicals; Factory and trade waste -- Periodicals; Organic wastes -- Periodicals; Bioénergie -- Périodiques; Déchets agricoles -- Périodiques; Déchets industriels -- Périodiques; Déchets organiques -- Périodiques; Déchets (Combustible) -- Périodiques; 662.88
• DOI: 10.1016/j.biortech.2016.07.060
• Languages: English
• ISSNs: 0960-8524

Abstract

Graphical abstract: Highlights: Targeted metabolite analysis is effective for finding rate-limiting metabolic steps. AtoB and AdhE1 catalyze rate-limiting steps in ABE production. Overexpression of thl (atoB) and adhE1 gene increase solvent productivity. Ex situ product-recovery fermentation increases ABE productivity and concentration. Abstract: In this study, metabolic target reactions for strain engineering were searched via intracellular coenzyme A (CoA) metabolite analysis. The metabolic reactions catalyzed by thiolase (AtoB) and aldehyde-alcohol dehydrogenase (AdhE1) were considered potential rate-limiting steps. In addition, CoA transferase (CtfAB) was highlighted as being important for the assimilation of organic acids, in order to achieve high butanol production. Based on this quantitative analysis, the BEKW_E1AB-atoB strain was constructed by overexpressing the thl ( atoB ), adhE1, and ctfAB genes in Clostridium acetobutylicum strain BEKW, which has the phosphotransacetylase ( pta ) and butyrate kinase ( buk ) genes knocked out. After 100 h of continuous fermentation coupled with adsorptive ex situ butanol recovery, the concentrations found after considering desorption, yield, and productivity for the BEKW_E1AB-atoB strain were 55.7 g/L, 0.38 g/g, and 2.64 g/L/h, respectively. The level of butanol production achieved (2.64 g/L/h) represents the highest reported value obtained after adsorptive, long-term fermentation.