FIG 1.

Glucose, fructose, and benzoate metabolism in P. putida KT2440 through the Entner-Doudoroff (ED) pathway, the Embden-Meyerhof-Parnas (EMP) pathway, and the β-ketoadipate pathway. Glucose transport into the cytoplasm is mediated through an ABC uptake system and phosphorylated to glucose-6-phosphate (G6P) and further to 6-phosphogluconate (6PG). Alternatively, glucose diffuses into the periplasm and is converted into gluconate and 2-ketogluconate (39). These intermediates are transported to the cytoplasm and are subsequently phosphorylated and reduced to 6-phosphogluconate, which is further metabolized by Entner-Doudoroff pathway enzymes or the pentose phosphate pathway enzymes. Fructose is transported into the cytoplasm by a PTS permease system and converted first to fructose-1-phosphate (F1P) and then to fructose-1,6-bisphosphate (FBP). FBP can then follow a reverse/anabolic EMP route and then enter the ED pathway or be processed by the standard glycolytic EMP route. Benzoate uptake into the cytoplasm is mediated by a permease (65) and is then processed by the β-ketoadipate pathway enzymes, resulting in the central intermediates acetyl coenzyme A (AcCoA) and succinate (SUCC). The metabolic intermediates involved in the corresponding pathways are abbreviated as follows: F6P, fructose-6-phosphate; R5P, ribulose-5-phosphate; GAP, glyceraldehyde-3-phosphate; DHAP, dihydroxyacetone phosphate; PYR, pyruvate.