Figure 1.

Carbon and electron flow in E. coli K24KP. Main metabolic pathways involved in glucose and glycerol catabolism for recombinant strain K24KP, carrying phaBAC and phaP from Azotobacter sp. strain FA8. Relevant native biochemical pathways and enzymes are shown by blue arrows and boxes, respectively. The heterologous pathway for PHB synthesis and enzymes involved are depicted in green. Dashed lines represent more than one biochemical step. Pathways that generate ATP are indicated by yellow arrows, while reduction/oxidation of adenine dinucleotides are represented by green and red arrows, respectively. Abbreviations used are as follows: PEP, phosphoenolpyruvate; CoA, coenzyme A; LdhA, D-lactate dehydrogenase; Pfl, pyruvate-formate lyase; Pdh, pyruvate dehydrogenase; Pta/AckA, phosphotransacetylase/acetate kinase; AdhE, acetaldehyde/alcohol dehydrogenase; PhaB, 3-ketoacyl-CoA thiolase; PhaA, acetoacetyl-CoA reductase; PhaC, poly(3-hydroxyalkanoate) synthase.