Figure 1
From: Modulation of endogenous pathways enhances bioethanol yield and productivity in Escherichia coli
Central metabolic pathways of E. coli functional under anaerobic condition during glucose and xylose fermentation. Relevant genes and corresponding enzymes are shown. Pyruvate dehydrogenase (PDH) operon was expressed under anaerobic condition via promoter replacement and is represented as thick line. The competing pathways to ethanol were blocked as shown by two parallel bars. Broken arrows represent multiple reactions of a pathway. Extracellular metabolites are placed in boxes. Abbreviations are as follows: ADH, acetaldehyde/alcohol dehydrogenase; ACK, acetate kinase; FHL, formate hydrogen-lyase; FRD, fumarate reductase; LDH, lactate dehydrogenase; PDH, pyruvate dehydrogenase; PFL, pyruvate formate-lyase; PTA, phosphate acetyltransferase; PYK, pyruvate kinase.