Skip to main content
Fig. 1 | Biotechnology for Biofuels

Fig. 1

From: Metabolic engineering of Escherichia coli for the production of butyric acid at high titer and productivity

Fig. 1

Butyrate pathway in the recombinant E. coli strains used in this study. In this proposed pathway, xylose is transported by the ABC transporter (XylFGH) and glucose is transported by its PTS system. PPP, pentose-phosphate pathway; PFL, pyruvate formate–lyase; FHL, formate hydrogen–lyase; THL, thiolase; HBD, hydroxybutyryl-CoA dehydrogenase; CRT, crotonase; TER, transenoyl-CoA reductase; PTB, phosphotransbutyrylase; BUK, butyrate kinase. HBD, CRT, PTB and BUK are from C. acetobutylicum. Ter is from T. denticola. Other enzymes are from E. coli. The native pathways of anaerobically growing E. coli at the pyruvate/phosphoenolpyruvate node and the mutations (marked by “X”) in strain BEM9 are listed in the boxed area. PFL, another native enzyme at the pyruvate node catalyzes the conversion of pyruvate to acetyl-CoA, the starting point of the butyrate pathway. PYK, pyruvate kinase; FRD-ABCD, fumarate reductase, the terminal enzyme of the PEP-succinate pathway; PTA, phosphotransacetylase; ACK-A, acetate kinase; ADH-E, acetaldehyde/alcohol dehydrogenase; LDH, D-lactate dehydrogenase

Back to article page