Kinetic and Regulatory Properties of Citrate Synthase from the Thermophilic Green Gliding Bacterium Chloroflexus Aurantiacus

  • D. J. Kelly


Chloroflexus aurantiacus is a photosynthetic member of a group of microbes which represent an extremely deep branching in the eubacterial line of descent (Gibson et al., 1985; Oyaizu et al., 1987). The other genera in this grouping, the green nonsulphur bacteria, are Herpetosiphon and Thermomicrobium, with which Chloroflexus shares little apparent phenotypic resemblance. Rlthough Chloroflexus contains BChl a and c, the latter localized in chlorosomes attached to the cytoplasmic membrane, 16S rRNA sequencing studies have shown no phylogenetic relatedness to the green sulphur bacteria (Gibson et al., 1985). Indeed, in terms of reaction centre photochemistry (Blankenship et al., 1983), some aspects of electron transport (Bruce et al., 1982) and the wide range of carbon sources utilized for photoheterotrophic or chemoheterotrophic growth (Madigan et al. f 1974), the metabolism of Chloroflexus most resembles that of the purple nonsulphur bacteria. Unlike the Rhodospirillaceae, however, the Calvin cycle is apparently not used to fix CO2 into cell material under autotrophic growth conditions (Holo and Sirevág, 1986) and a novel mechanism has been postulated. In addition, the thermophilic character of Chloroflexus (optimum growth at 55°C) is seemingly rare amongst phototrophic bacteria.


Malate Dehydrogenase Green Sulphur Bacterium maLate Dehydrogenase Activity Reaction Centre Photochemistry Green Photosynthetic Bacterium 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. Achenbach-Richter, L., Gupta, R., Stetter, K.O., and Woese, C.R., 1987, Were the original eubacteria thermophiles?. System, Appl. Microbiol., 9:34.Google Scholar
  2. Blankenship, R.E., Feick, R., Bruce, B.D., Kirmaier, C., Holton, D., and Fuller,R.C., 1983, Primary photochemistry in the facultative green photosynthetic bacterium Chloroftexus aurantiacus, J. Cell Biochem., 22:251.PubMedCrossRefGoogle Scholar
  3. Brock, T.D., 1967, Life at high temperatures, Science, 158:1012.PubMedCrossRefGoogle Scholar
  4. Bruce, B., Fuller, R.C., and Blankenship, R, E., 1982, Primary photochemistry in the facultative aerobic green photosynthetic bacterium Chloroftexus aurantiacus, Proc. Natl. Read. Sci. U.S.A., 79:6532.CrossRefGoogle Scholar
  5. Dean, P.D.G., and Watson, D.H., 1979, Protein purificaiton using immobilised triazine dyes, J. Chromatography, 165:301.CrossRefGoogle Scholar
  6. Gibson, J., Stackebrandt, E., and Woese, C.R., 1985, The phytogeny of the green photosynthetic bacteria: lack of a close relationship between Chlorobium and Chloroftexus, System, Appl. Microbiol,, 6:152.Google Scholar
  7. Holo, H., and Sirevág, R., 1986, Autotrophic growth and CO2 fixation of Chloroftexus aurantiacus, Arch. Microbiol., 145:173.CrossRefGoogle Scholar
  8. Jürgens, U, J., Meissner, J., Fischer, U., König, W.A., and Weckesser, J., 1987, Ornithine as a constituent of the peptidoglycan of Chloroftexus aurantiacus, diaminopimelic acid in that of Chlorobium vibrioforme f. thiosulfatophilum, Arch. Microbiol., 148:72.CrossRefGoogle Scholar
  9. Madigan, M., Peterson, S.R., and Brock, T.D., 1974, Nutritional studies on Chloroftexus. a filamentous photosynthetic gliding bacterium, Arch. Microbiol., 100:97.CrossRefGoogle Scholar
  10. Oyaizu, H., Debrunner-Vossbrinck, B., Mandelco, L., Studier, J.R., and Woese, C.R., 1987, The green non-sulfur bacteria: A deep branching in the eubacterial line of descent, System. Appl. Microbiol., 9:47.Google Scholar
  11. Pierson, B.K., and Castenholz, R.W., 1974, A phototrophic gliding filamentous bacterium of hot springs, Chloroflexus aurantiacus,gen. and sp. nov., Arch. Microbiol., 100:5.Google Scholar
  12. Reeves, H.C., Rabin, R., Wegener, W.S., and Ajl, S.J., 1971, Assay of enzymes of the tricarboxylic acid and glyoxylate cycles, Methods in Microbiol., GA:425.Google Scholar
  13. Weaver, P.F., Wall, J.D., and Gest, H.1975, Characterization of Rhodopseudomonas capsulata, Arch. Microbiol., 105:207.PubMedCrossRefGoogle Scholar
  14. Weitzman, P.D.J., 1976, Anomalous citrate synthase from Thermus aquaticus, J. Gen. Microbiol., 106:303.Google Scholar
  15. Weitzman, P.D.J., 1961, Unity and diversity in some bacterial citric acid cycle enzymes, Adv. Microb. Physiol., 22:165.Google Scholar
  16. Weitzman, P.O.J., and Danson, M.J., 1976, Citrate synthase, Curr. Top. Cell. Reg. 10:161.Google Scholar
  17. Williams, R.A.D., 1975, Caldoactive and thermophilic bacteria and their thermostable proteins, Sci. Prog. (Oxford), 62:373.Google Scholar
  18. Woese, C.R., 1987, Bacterial evolution, Microbiol,. Revs., 51:221.Google Scholar

Copyright information

© Plenum Press, New York 1988

Authors and Affiliations

  • D. J. Kelly
    • 1
  1. 1.Department of MicrobiologyUniversity of SheffieldWestern Bank, SheffieldUK

Personalised recommendations