Archives of Microbiology

, Volume 145, Issue 2, pp 173–180 | Cite as

Autotrophic growth and CO2 fixation of Chloroflexus aurantiacus

  • Helge Holo
  • Reidum Sirevåg
Original Papers


Chlorofluexus aurantiacus OK-70 fl was grown photoautotrophically with hydrogen as the electron source. The lowest doubling time observed was 26 h.

The mechanism of CO2 fixation in autotrophically grown cells was studied. The presence of ribulose-1,5-bis-phosphate carboxylase and phosphoribulokinase could not be demonstrated. Carbon isotope fractionation (δ13C) was small, and alanine and aspartate but not 3-phosphoglycerate were the major labelled compounds in short term 14CO2 labelling. Thus CO2 is not fixed by the Calvin cycle.

Fluoroacetate (FAc) completely inhibited protein synthesis in cultures and caused a slight citrate accumulation. However, CO2 fixation continued and increased polyglucose formation occurred. Under these conditions added acetate was metabolized to polyglucose, as were glycine, serine, glyoxylate and succinate, but to a lesser extent; little or no formate or CO was utilised.

Glyoxylate inhibited CO2 fixation in vivo, indicating that pyruvate is formed from acetyl-CoA and CO2 by pyruvate synthase. Two key enzymes of the reductive TCA cycle, citrate lyase and α-ketoglutarate synthase were not detected in cell free extracts, but pyruvate synthase and phosphoenolpyruvate carboxylase were demonstrated. It is concluded that acetyl-CoA is a central intermediate in the CO2 fixation process, but the mechanism of its synthesis is not clear.

Key words

Chloroflexus Autotrophic growth CO2 fixation pathway Calvin cycle Pyruvate synthase 



ribulose-1,5-bisphosphate carboxylase

TCA cycle

tricarboxylic acid cycle






methyl viologen


triphenyltetrazolium chloride


phenazine methosulfate


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. Allen TH, Root WS (1955) Colorimetric determination of carbon monoxide in air by an improved palladium chloride method. J Biol Chem 216:309–317Google Scholar
  2. Berg P (1956) Acyladenylates: An enzymatic mechanism of acetate activation. J Biol Chem 222:991–1013Google Scholar
  3. Buchanan BB (1972) Ferredoxin linked carboxylation reactions. In: Boyer PD (ed) The enzymes, 3. edn, vol VI. Academic Press, New York, pp 193–216Google Scholar
  4. Cooper RA, Kornberg HL (1974) Phosphoenolpyruvate synthetase and pyruvate phosphate dikinase. In: Boyer PD (ed) The enzymes, 3. edn, vol 10. Academic Press, New York, pp 631–649Google Scholar
  5. Craigh HH (1957) Isotope standards for carbon and oxygen and correction factors for mass spectrometric analysis for carbon dioxide. Geochim Cosmochim Acta 12:133–149Google Scholar
  6. Dieckert G, Hansch M, Conrad R (1984) Acetate synthesis from 2 CO2 in acetogenic bacteria: is carbon monoxide an intermediate? Arch Microbiol 138:224–228Google Scholar
  7. Drutschmann M, Klemme JH (1985) Sulfide repressed, membrane bound hydrogenase in the thermophilic facultative phototroph, Chloroflexus aurantiacus. FEMS Microbiol Lett 28:231–235Google Scholar
  8. Dürre P, Andreesen JR (1982) Pathway of carbon dioxide reduction to acetate without a net energy requirement in Clostridium purinolyticum. FEMS Microbiol Lett 15:51–56Google Scholar
  9. Evans MCW, Buchanan BB, Arnon DI (1966) A new ferredoxin dependent carbon reduction cycle in a photosynthetic bacterium. Proc Natl Acad Sci USA 55:928–934Google Scholar
  10. Fox GE, Stackebrandt E, Hespell RB, Gibson J, Maniloff J, Dyer TA, Wolfe RS, Balch WE, Tanner RS, Magrum LJ, Zablen LB, Blakemore R, Gupta R, Bonen L, Lewis BJ, Stahl DA, Luehrsen KR, Chen KN, Woese CR (1980) The phylogeny of procaryotes. Science 209:457–463Google Scholar
  11. Fuchs G, Schnitker U, Thauer RK (1974) Carbon monoxide oxidation by growing cultures of Clostridium pasteurianum. Eur J Biochem 49:111–115Google Scholar
  12. Fuchs G, Stupperich E, Eden G (1980) Autotrophic CO2 fixation in Chlorobium limicola. Evidence for the operation of a reductive tricarboxylic acid cycle in growing cells. Arch Microbiol 128:64–71Google Scholar
  13. Hall NP, Cornelivs MJ, Keys AJ (1983) The enzymatic determination of bicarbonate and CO2 in reagents and buffer solutions. Anal Biochem 132:152–157Google Scholar
  14. Hart BA, Gibson J (1975) Ribulose-5-phosphate kinase from Chromatium. In: Wood WA (ed) Methods in enzymology, vol XLII. Academic Press, New York, pp 115–119Google Scholar
  15. Hatch MD, Slack RC (1970) Photosynthetic CO2 fixation pathways. Ann Rev Plant Physiol 21:141–162Google Scholar
  16. Knowles FC, Benson AA (1983) The biochemistry of arsenic. Trends Biochem Sci 8:178–180Google Scholar
  17. Lowry OH, Rosenbrough MS, Farr AL, Randall RS (1951) Protein measurements with the Folin phenol reagent. J Biol Chem 193:265–275Google Scholar
  18. Løken Ø, Sirevåg R (1982) Evidence for the presence of the glyoxylate cycle in Chloroflexus. Arch Microbiol 132:276–279Google Scholar
  19. Madigan M (1976) Studies on the physiological ecology of Chloroflexus aurantiacus, a filamentous photosynthetic bacterium. Ph. D. disseration, University of Wisconsin-Madison.Google Scholar
  20. Madigan MT, Petersen SR, Brock TD (1984) Nutritional studies on Chloroflexus, a filamentous, photosynthetic, gliding bacterium. Arch Microbiol 100:97–103Google Scholar
  21. Massey V (1955) Fumarase. In: Colowick SP, Kaplan NO (eds) Methods in enzymology, vol 1. Academic Press, New York, pp 729–735Google Scholar
  22. Ochoa S (1955) Crystalline condensing enzyme from pig heart. In: Colowick SP, Kaplan NO (eds) Methods in enzymology, vol 1. Academic Press, New York, pp 685–694Google Scholar
  23. Ormerod JG (1980) Photosynthesis of acetate from carbon dioxide. 3rd Int Symp on Microbial Growth on C1 Compounds, Sheffield, Abstracts of posters: 99–100Google Scholar
  24. Park R, Epstein S (1960) Carbon isotope fractionation during photosynthesis. Geochim Cosmochim Acta 21:110–126Google Scholar
  25. Peters RA, Wakelin RW, Rivett DEA, Thomas LC (1953) Fluoroacetae poisoning: Comparison of synthetic fluorocitric acid with the enzymically synthesized fluorotricarboxylic acid. Nature 171:1111–1112Google Scholar
  26. Quayle JR (1972) The metabolism of one-carbon compounds in microorganisms. Adv Microb Physiol 7:119–203Google Scholar
  27. Raeburn S, Rabinowitz JC (1971) Pyruvate: Ferredoxin oxido-reductase 1. The pyruvate-CO2 exchange reaction. Arch Biochem Biophys 146:9–20Google Scholar
  28. Rose IA, O'Connell EL (1967) Mechanism of aconitase action. J Biol Chem 1870–1879Google Scholar
  29. Schürmann P (1969) Separation of phosphate esters and algal extracts by thin-layer electrophoresis and chromatography. J Chromat 39:507–509Google Scholar
  30. Scrutton MC, Young MR (1972) Pyruvate carboxylase. In: Boyer PD (ed) The enyzmes, 3. edn, vol 6. Academic Press, New York, pp 1–35Google Scholar
  31. Siebert K, Schobert P, Bowien B (1981) Purification, some catalytic and molecular properties of phosphoribulokinase from Alcaligenes eutrophus. Biochim Biophys Acta 658:35–44Google Scholar
  32. Sirevåg R (1974) Further studies on carbon dioxide fixation in green sulphur bacteria. Arch Microbiol 98:3–18Google Scholar
  33. Sirevåg R (1975) Photoassimilation of acetate and metabolism of carbohydrate in Chlorobium thiosulfatophilum. Arch Microbiol 104:105–111Google Scholar
  34. Sirevåg R, Castenholz R (1979) Aspects of carbon metabolism in Chloroflexus. Arch Microbiol 120:151–153Google Scholar
  35. Sirevåg R, Ormerod JG (1970) Carbon dioxide fixation in green sulfur bacteria. Biochem J 120:399–408Google Scholar
  36. Sirevåg R, Buchanan BB, Berry JA, Troughton JH (1977) Mechanisms of CO2 fixation in bacterial photosynthesis studied by the carbon isotope fractionation technique. Arch Microbiol 112:35–38Google Scholar
  37. Stupperich E, Hammel KE, Fuchs G, Thauer RK (1983) Carbon monoxide fixation into the carboxyl group of acetyl coenzyme A during autotrophic growth of Methanobacterium. FEBS Lett 152:21–23Google Scholar
  38. Tabita RF, McFadden B, Pfennig N (1974) d-Ribulose 1,5-biphosphate carboxylase in Chlorobium thiosulfatophilum Tassajara. Biochim Biophys Acta 341:187–194Google Scholar
  39. Taylor TG (1953) A modified procedure for the microdetermination of citric acid. Biochem J 54:48–49Google Scholar
  40. Thauer RK, Rupprecht E, Jungermann K (1970a) Glyoxylate inhibition of clostridial pyruvate synthase. FEBS Lett 9:271–273Google Scholar
  41. Thauer RK, Rupprecht E, Jungermann K (1970b) The synthesis of one carbon units from CO2 via a new ferredoxin dependent monocarboxylic acid cycle. FEBS Lett 8:304–307Google Scholar

Copyright information

© Springer-Verlag 1986

Authors and Affiliations

  • Helge Holo
    • 1
  • Reidum Sirevåg
    • 1
  1. 1.Department of Biology, Division of Molecular Cell BiologyUniversity of OsloOslo 3Norway

Personalised recommendations