1887

Abstract

SUMMARY: A mutant of is shown to have an absolute requirement for riboflavin when grown at 30°, but this requirement is less stringent when the organism is grown at 25°. The Fe, Cu, Zn, Mn and Mo requirements of the mutant, grown at either temperature, are similar to those of the wild type (146) so that it seems unlikely that these metals are involved in the biosynthesis of riboflavin. A study of enzyme patterns in the mutant, grown at 30° and given optimal or deficient concentrations of riboflavin, demonstrated alternative pathways of electron transfer in the fungus. When riboflavin is deficient, the iron enzymes are markedly increased and oxygen is probably the main terminal acceptor of the electrons. At optimal concentrations of riboflavin, the flavoprotein enzymes are produced and nitrate and nitrite reductases are active so that nitrate can act as a terminal acceptor. Iron deficiency is readily produced in the mutant when riboflavin is deficient because of the increased activity of iron enzymes; a molybdenum requirement is greater at optimal riboflavin concentrations because of the enhanced production of molybdo-flavoproteins.

Loading

Article metrics loading...

/content/journal/micro/10.1099/00221287-15-3-470
1956-12-01
2024-12-12
Loading full text...

Full text loading...

/deliver/fulltext/micro/15/3/mic-15-3-470.html?itemId=/content/journal/micro/10.1099/00221287-15-3-470&mimeType=html&fmt=ahah

References

  1. Bessey O. A., Lowry O. H., Brock M. J. 1946; A method for the rapid determination of alkaline phosphatase with five cubic millimetres of serum. J. biol. Chem 164:321
    [Google Scholar]
  2. Crane R. K., Sols A. 1953; Animal tissue hexokinases, in Methods in Enzymology,. I p. 277 Colowick S. P., Kaplan N. O. Ed New York: Academic Press;
    [Google Scholar]
  3. Feinstein R. N. 1949; Perborate as substrate in a new assay of catalase. J. biol. Chem 180:1197
    [Google Scholar]
  4. Lenhoff M. H., Nicholas D. J. D., Kaplan N. O. 1956; Effects of oxygen, iron, and molybdenum on alternative routes of terminal electron transfer in Pseudomonas fluorescens. J. biol. Chem 220:983
    [Google Scholar]
  5. Mitchell H. K., Houlahan M. B. 1946; Neurospora (IV). A temperature-sensitive riboflavinless mutant. Amer. J. Bot 33:31
    [Google Scholar]
  6. Najjar V. A. 1955; Phosphoglucomutase from muscle, in Methods in Enzymology. I p. 294 Colowick S. P., Kaplan N. O. Ed New York: Academic Press;
    [Google Scholar]
  7. Nason A., Zucker M. 1956; Nitroarylreductase from Neurospora crassa, in Methods in Enzymology. II p. 406 Colowick S. P., Kaplan N. O. Ed New York: Academic Press;
    [Google Scholar]
  8. Nicholas D. J. D. 1952; The use of fungi for determining trace metals in biological materials. Analyst 77:629
    [Google Scholar]
  9. Nicholas D. J. D., Nason A. 1954; Mechanism of action of nitrate reductase from Neurospora. J. biol. Chem 211:183
    [Google Scholar]
  10. Pullman M. E., Colowick S. P., Kaplan N. O. 1954; Comparison of diphosphopyridine nucleotide with its deaminated derivative in various enzyme systems. J. biol. Chem 194:593
    [Google Scholar]
  11. Robinson H. W., Hogden C. G. 1940; Biuret reaction in determination of serum proteins. J. biol. Chem 135:727
    [Google Scholar]
  12. Smith F. G., Robinson W. B., Stotz E. 1949; A colorimetric method for the determination of peroxidase in plant material. J. biol. Chem 179:881
    [Google Scholar]
  13. Smith F. G., Stotz E. 1949; A colorimetric method for the determination of cytochrome oxidase. J. biol. Chem 179:891
    [Google Scholar]
  14. Whelan W. J. 1955; Phosphorylases from plants in Methods in Enzymology. I p. 192 Colowick S. P., Kaplan N. O. Ed New York: Academic Press;
    [Google Scholar]
/content/journal/micro/10.1099/00221287-15-3-470
Loading
/content/journal/micro/10.1099/00221287-15-3-470
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