Sulfoquinovose (SQ) is a major metabolite in the global sulfur cycle produced by nearly all photosynthetic organisms. One of the major pathways involved in the catabolism of SQ in bacteria, such as Escherichia coli, is a variant of the glycolytic Embden-Meyerhof-Parnas (EMP) pathway termed the sulfoglycolytic EMP (sulfo-EMP) pathway, which leads to consumption of three of the six carbons of SQ and excretion of 2,3-dihydroxypropanesulfonate (DHPS). Comparative metabolite profiling of aerobically

more »

... Glc-grown and SQ-grown E. coli was undertaken to identify the metabolic consequences of switching from glycolysis to sulfoglycolysis. Sulfoglycolysis was associated with the diversion of triose-phosphates to synthesize sugar phosphates (gluconeogenesis), and an unexpected accumulation of trehalose and glycogen storage carbohydrates. Sulfoglycolysis was also associated with global changes in central carbon metabolism, as indicated by changes in levels of intermediates in the tricarboxylic acid (TCA) cycle, the pentose phosphate pathway (PPP), polyamine metabolism, pyrimidine metabolism and many amino acid metabolic pathways. Upon entry into stationary phase and depletion of SQ, E. coli utilize their glycogen, indicating a reversal of metabolic fluxes to allow glycolytic metabolism.