Metabolism of D-fructose by Arthrobacter pyridinolis.
Previous studies showed that Arthrobacter pyridinolis can transport and utilize d-glucose only after prior growth on certain Krebs cycle intermediates. In contrast, we found that d-fructose was taken up and metabolized by A. pyridinolis without special prior conditions of growth. d-Fructose was first converted to d-fructose-1-phosphate by a phosphoenolpyruvate (PEP):D-fructose phosphotransferase. This activity required both supernatant and pellet fractions from d-fructose-grown cells centrifuged at 150,000 x g. The d-fructose-1-phosphate formed was converted to d-fructose-1, 6-diphosphate. Mutants deficient in PEP:d-fructose phosphotransferase and d-fructose-1-phosphate kinase, or d-fructose-1, 6-diphosphatase (FDPase) were unable to grow on d-fructose but retained the normal ability to use d-glucose. Mutants forming reduced amounts of FDPase were completely unable to grow on d-fructose but were still capable of limited growth on Krebs cycle intermediates. A requirement for higher levels of FDPase for growth on d-fructose than for growth on Krebs cycle intermediates was also indicated by the higher specific activities of FDPase in d-fructose-grown cells than in cells grown on l-malate or amino acids.
D001173:Arthrobacter / Q000201:enzymology / Q000254:growth & development / Q000378:metabolism*; D002247:Carbon Isotopes; D002474:Cell-Free System; D003470:Culture Media; D005632:Fructose / Q000378:metabolism*; D006597:Fructose-Bisphosphatase / Q000378:metabolism; D005636:Fructosephosphates / Q000096:biosynthesis; D005941:Glucokinase / Q000378:metabolism; D005947:Glucose / Q000378:metabolism; D005971:Glutamates / Q000378:metabolism; D006598:Hexosediphosphates / Q000096:biosynthesis; D008293:Malates / Q000378:metabolism; D009154:Mutation; D010728:Phosphoenolpyruvate; D010732:Phosphofructokinase-1 / Q000378:metabolism; D010770:Phosphotransferases / Q000096:biosynthesis / Q000378:metabolism; D013053:Spectrophotometry; D013237:Stereoisomerism; D014461:Ultracentrifugation
D002247:Carbon Isotopes; D003470:Culture Media; D005636:Fructosephosphates; D005971:Glutamates; D006598:Hexosediphosphates; D008293:Malates; D005632:Fructose; D010728:Phosphoenolpyruvate; D010770:Phosphotransferases; D010732:Phosphofructokinase-1; D005941:Glucokinase; D006597:Fructose-Bisphosphatase; D005947:Glucose