1887

Abstract

In aerobic chemostat culture A2-GFI grew autotrophically on formate and heterotrophically on glucose with maximum specific growth rates (μ) of 0·21 and 0·33 h, respectively. At dilution rates of 0·1 and 0·18 h, it grew mixotrophically on formate + glucose mixtures, completely consuming both substrates. Ribulose-1,5-bisphosphate carboxylase and formate dehydrogenase were present at high specific activity in autotrophic and mixotrophic cultures, but were repressed in cultures on glucose alone. A greater proportion of added glucose was assimilated in mixotrophic culture than in heterotrophic culture. Raising the dilution rate of a mixotrophic culture from 0·1 or 0·18 to 0·3 h resulted in washout (with an apparent for mixotrophic growth of 0·25 h) and the establishment of a culture dependent on glucose for growth. Growth yields on formate and glucose were, respectively, 3·3 and 100 g dry wt (mol substrate consumed). Steady state biomass production in mixotrophic culture indicated additive growth yields. The biomass produced in cultures on formate + glucose at a dilution rate of 0·3 h suggested that growth only occurred on glucose, but organisms still contained high activities of ribulose-1,5-bisphosphate carboxylase and formate dehydrogenase. At a formate: glucose ratio (m) of 100:1, some formate was oxidized and CO was fixed, but formate was not used when this ratio was 50:5. Formate-glucose mixotrophy benefits A2-GFI when substrates are limited at low growth rates (< for formate), but is characterized by a below that possible on glucose. Physiological behaviour at high growth rates was influenced by the formate:glucose ratio, resulting under some conditions, at least, in loss of mixotrophy and the establishment of heterotrophic growth.

Loading

Article metrics loading...

/content/journal/micro/10.1099/00221287-125-1-55
1981-07-01
2021-07-31
Loading full text...

Full text loading...

/deliver/fulltext/micro/125/1/mic-125-1-55.html?itemId=/content/journal/micro/10.1099/00221287-125-1-55&mimeType=html&fmt=ahah

References

  1. Dijkhuizen L. 1979 Regulation of autotrophic and heterotrophic metabolism in Pseudomonas oxalaticus OX1. Doctoral thesis Rijksuniversiteit Groningen; The Netherlands:
    [Google Scholar]
  2. Dijkhuizen L., Harder W. 1979; Regulation of autotrophic and heterotrophic metabolism in Pseudomonas oxalaticus OX1: growth on mixtures of oxalate and formate in continuous culture. Archives of Microbiology 123:55–63
    [Google Scholar]
  3. Gottschal J. C. 1980 Mixotrophic growth of Thiobacillus A2 and its ecological significance. Doctoral thesis Rijksuniversiteit Groningen; The Netherlands.:
    [Google Scholar]
  4. Gottschal J. C., Kuenen J. G. 1980; Mixotrophic growth of Thiobacillus A2 on acetate and thiosulphate as growth limiting substrates in the chemostat. Archives of Microbiology 126:33–42
    [Google Scholar]
  5. Gottschal J. C., De Vries S., Kuenen J. G. 1979; Competition between the facultatively chemolithotrophic Thiobacillus A2, an obligately chemolithotrophic Thiobacillus and a heterotrophic Spirillum for inorganic and organic substrates. Archives of Microbiology 121:241–249
    [Google Scholar]
  6. Karagouni A., Slater J. H. 1978; Growth of the blue-green alga Anacystis nidulans during washout from light- and carbon dioxide-limited chemostats. FEMS Microbiology Letters 4:295–299
    [Google Scholar]
  7. Kelly D. P. 1971; Autotrophy: concepts of lithotrophic bacteria and their organic metabolism. Annual Review of Microbiology 25:177–210
    [Google Scholar]
  8. Kelly D. P., Wood A. P., Gottschal J. C., Kuenen J. G. 1979; Autotrophic metabolism of formate by Thiobacillus strain A2. Journal of General Microbiology 114:1–13
    [Google Scholar]
  9. Matin A. 1978; Organic nutrition of chemolithotrophic bacteria. Annual Review of Microbiology 32:433–468
    [Google Scholar]
  10. Reeves R. E., South D. J., Blytt H. J., Warren L. G. 1974; Pyrophosphate: d-fructose 6-phosphate 1-phosphotransferase. A new enzyme with the glycolytic function of 6-phosphofructokinase. Journal of Biological Chemistry 249:7737–7741
    [Google Scholar]
  11. Silver M., Kelly D. P. 1976; Rhodanese from Thiobacillus A2: catalysis of reactions of thiosulphate with dihydrolipoate and dihydrolipoamide. Journal of General Microbiology 97:277–284
    [Google Scholar]
  12. Smith A. L., Kelly D. P. 1979; Competition in the chemostat between an obligately and a facultatively chemolithotrophic Thiobacillus. Journal of General Microbiology 115:377–384
    [Google Scholar]
  13. Smith A. L., Kelly D. P., Wood A. P. 1980; Metabolism of Thiobacillus A2 grown under autotrophic, mixotrophic and heterotrophic conditions in chemostat culture. Journal of General Microbiology 121:127–138
    [Google Scholar]
  14. Somogyi M. 1945; A new reagent for the determination of sugars. Journal of Biological Chemistry 160:61–68
    [Google Scholar]
  15. Taylor B. F., Hoare D. S. 1969; New facultative Thiobacillus and a re-evaluation of the heterotrophic potential of Thiobacillus novellus. Journal of Bacteriology 100:487–497
    [Google Scholar]
  16. Wood A. P., Kelly D. P. 1977; Heterotrophic growth of Thiobacillus A2 on sugars and organic acids. Archives of Microbiology 113:257–264
    [Google Scholar]
  17. Wood A. P., Kelly D. P. 1978; Triple catabolic pathways for glucose in a fast-growing strain of Thiobacillus A2. Archives of Microbiology 117:309–310
    [Google Scholar]
  18. Wood A. P., Kelly D. P. 1979; Glucose catabolism by Thiobacillus A2 grown in chemostat culture under carbon or nitrogen limitation. Archives of Microbiology 122:307–312
    [Google Scholar]
  19. Wood A. P., Kelly D. P. 1980a; Carbohydrate degradation pathways in Thiobacillus A2 grown on various sugars. Journal of General Microbiology 120:333–345
    [Google Scholar]
  20. Wood A. P., Kelly D. P. 1980b; Regulation of glucose catabolism in Thiobacillus A2 grown in the chemostat under dual limitation by succinate and glucose. Archives of Microbiology 128:91–97
    [Google Scholar]
  21. Wood A. P., Kelly D. P., Thurston C. F. 1977; Simultaneous operation of three catabolic pathways in the metabolism of glucose by Thiobacillus A2. Archives of Microbiology 113:265–274
    [Google Scholar]
http://instance.metastore.ingenta.com/content/journal/micro/10.1099/00221287-125-1-55
Loading
/content/journal/micro/10.1099/00221287-125-1-55
Loading

Data & Media loading...

This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error