1887

Abstract

is an endophytic diazotroph of sugarcane which exhibits nitrogenase activity when growing in colonies on solid media. Nitrogenase activity of colonies can adapt to changes in atmospheric partial pressure of oxygen (pO). This paper investigates whether colony structure and the position of cells in the colonies are components of the bacterium’s ability to maintain nitrogenase activity at a variety of atmospheric pO values. Colonies of were grown on solid medium at atmospheric pO of 2 and 20 kPa. Imaging of live, intact colonies by confocal laser scanning microscopy and of fixed, sectioned colonies by light microscopy revealed that at 2 kPa O the uppermost bacteria in the colony were very near the upper surface of the colony, while the uppermost bacteria of colonies cultured at 20 kPa O were positioned deeper in the mucilaginous matrix of the colony. Disruption of colony structure by physical manipulation or due to ‘slumping’ associated with colony development resulted in significant declines in nitrogenase activity. These results support the hypothesis that utilizes the path-length of colony mucilage between the atmosphere and the bacteria to achieve a flux of O that maintains aerobic respiration while not inhibiting nitrogenase activity.

Loading

Article metrics loading...

/content/journal/micro/10.1099/00221287-148-8-2293
2002-08-01
2020-01-25
Loading full text...

Full text loading...

/deliver/fulltext/micro/148/8/1482293a.html?itemId=/content/journal/micro/10.1099/00221287-148-8-2293&mimeType=html&fmt=ahah

References

  1. Barbosa H. R., Alterthum F. 1992; The role of extracellular polysaccharide in cell viability and nitrogenase activity of Beijerinckia derxii . Can J Microbiol38:986–988[CrossRef]
    [Google Scholar]
  2. Brown D. E. 1970; Aeration in the submerged culture of micro-organisms. Methods Microbiol2:125–174
    [Google Scholar]
  3. Burris R. H. 1991; Nitrogenases. J Biol Chem266:9339–9342
    [Google Scholar]
  4. Cavalcante V. A., Döbereiner J. 1988; A new acid-tolerant nitrogen-fixing bacterium associated with sugarcane. Plant Soil108:23–31[CrossRef]
    [Google Scholar]
  5. Dong Z., Canny M. J., McCully M. E., Roboredo M. R., Cabadilla C. F., Ortega E., Rodes R. 1994; A nitrogen-fixing endophyte of sugarcane stems. A new role for the apoplast. Plant Physiol105:1139–1147
    [Google Scholar]
  6. Dong Z., Heydrich M., Bernard K., McCully M. E. 1995; Further evidence that the N2 fixing endophytic bacterium from the intercellular spaces of sugarcane stems is Acetobacter diazotrophicus . Appl Environ Microbiol61:1843–1846
    [Google Scholar]
  7. Gillis M., Kersters K., Hoste B., Janssens D., Kroppenstedt R. M., Stephan M. P., Teixeira K. R. S., Döbereiner J., De Ley J. 1989; Acetobacter diazotrophicus sp. nov., a nitrogen-fixing acetic acid bacterium associated with sugarcane. Int J Syst Bacteriol39:361–364[CrossRef]
    [Google Scholar]
  8. Hill S. 1971; Influence of oxygen concentration on the colony type of Derxia gummosa grown on nitrogen free medium. J Gen Microbiol67:77–83[CrossRef]
    [Google Scholar]
  9. Hill S., Drozd J. W., Postgate J. R. 1972; Environmental effects on the growth of nitrogen-fixing bacteria. J Appl Chem22:541–558[CrossRef]
    [Google Scholar]
  10. Hunt S., Layzell D. B. 1993; Gas exchange of legume nodules and the regulation of nitrogenase activity. Annu Rev Plant Physiol Plant Mol Biol44:483–511[CrossRef]
    [Google Scholar]
  11. Oresnik I. J., Layzell D. B. 1994; Composition and distribution of adenylates in soybean ( Glycine max L.) nodule tissue. Plant Physiol104:217–225
    [Google Scholar]
  12. Pan B., Vessey J. K. 2001; Response of the endophytic diazotroph Gluconacetobacter diazotrophicus on solid media to changes in atmospheric pO2. Appl Environ Microbiol67:4694–4700[CrossRef]
    [Google Scholar]
  13. Reis V. M., Döbereiner J. 1998; Effect of high sugar concentration on nitrogenase activity of Acetobacter diazotrophicus . Arch Microbiol171:13–18[CrossRef]
    [Google Scholar]
  14. Robson R. L., Postgate J. R. 1980; Oxygen and hydrogen in biological nitrogen fixation. Annu Rev Microbiol34:183–207[CrossRef]
    [Google Scholar]
  15. Spurr A. R. 1969; A low viscosity epoxy resin embedding medium for electron microscopy. J Ultrastruct Res26:31–43[CrossRef]
    [Google Scholar]
  16. Sutherland I. W. 1999; Polysaccharases for microbial exopolysaccharides. Carbohydr Polymers38:319–328[CrossRef]
    [Google Scholar]
  17. van Cauwenberghe O. R., Newcomb W., Canny M. J., Layzell D. B. 1993; Dimensions and distribution of intercellular spaces in cryoplaned soybean nodules. Physiol Plant89:252–261[CrossRef]
    [Google Scholar]
  18. Yamada Y., Hoshino K., Ishikawa T. 1997; The phylogeny of acetic acid bacteria based on the partial sequences of 16S ribosomal RNA: the elevation of the subgenus Gluconoacetobacter to generic level. Biosci Biotechnol Biochem61:1244–1251[CrossRef]
    [Google Scholar]
  19. Zhulin I. B., Bespalov V. A., Johnson M. S., Taylor B. L. 1996; Oxygen taxis and proton motive force in Azospirillum brasiliense . J Bacteriol178:5199–5204
    [Google Scholar]
http://instance.metastore.ingenta.com/content/journal/micro/10.1099/00221287-148-8-2293
Loading
/content/journal/micro/10.1099/00221287-148-8-2293
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