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Uric acid utilization in Platymonas convolutae and symbiotic Convoluta roscoffensis

Published online by Cambridge University Press:  16 October 2009

A. E. Douglas
Affiliation:
Department of Microbiology, University of Aberdeen, Aberdeen

Abstract

Uric acid is an excellent nitrogen source for the growth of cultures of Platymonas convolutae, the symbiotic alga from Convoluta roscoffensis, and related Platymonas and Tetraselmis species. Nitrate-grown cells of P. convolutae and T. tetrathele have two uptake systems for uric acid, which conform to Michaelis–Menten kinetics; a high-affinity system operating in the concentration range 0·2–4·5 μM a nd a low-affinity system operating at higher concentrations of uric acid. Uric acid uptake by P. convolutae is abolished by uncouplers of phosphorylation. In darkness, intact cells of P. convolutae metabolize [2-14C]uric acid to [14C]carbon dioxide. These results are consistent with the proposal that the algal symbionts of C. roscoffensis utilize uric acid, received from the host, as a nitrogen source.

Aposymbiotic juvenile and symbiotic adult C. roscoffensis under standard culture conditions contain uric acid. The solid uric acid content of juveniles declines on establishment of symbiosis with P. convolutae and the endogenous uric acid is utilized in the adult symbiosis under conditions of nitrogen demand. However, adult C. roscoffensis do not utilize exogenous uric acid. The growth of adult but not juvenile C. roscoffensis is dependent on nitrogen enrichment of the medium, and it is proposed that uric acid utilization is of significance to the growth of the developing symbiosis in a nitrogen-poor environment.

Type
Research Article
Copyright
Copyright © Marine Biological Association of the United Kingdom 1983

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References

REFERENCES

Ammann, E. C. B. & Lynch, V. H., 1964. Purine metabolism by unicellular algae. I. Adenine, hypoxanthine and xanthine degradation by Chlorella pyrenoidosa. Biochimica et biophysica acta, 87, 370379Google Scholar
Ammann, E. C. B. & Lynch, V. H., 1966. Purine metabolism by unicellularalgae. II. Photochemical degradation of uric acid by chlorophyll. Biochimica et biophysica acta, 120, 181182.CrossRefGoogle Scholar
Antia, N. J. & Landymore, A. F., 1974. Physiological and ecological significance of the chemical instability of uric acid and related purines in sea water and marine culture medium. Journal of the Fisheries Research Board of Canada, 31, 13271335.CrossRefGoogle Scholar
Antia, N. J., Berland, B. R., Bonin, D. J. & Maestrini, S. Y., 1975. Comparative evaluation of certain organic and inorganic sources of nitrogen for phototrophic growth of marine microalgae. Journal of the Marine Biological Association of the United Kingdom, 55, 519539.CrossRefGoogle Scholar
Baalen, C. van, 1965. The photo-oxidation of uric acid by Anacystis nidulans. Plant Physiology, 40, 368371.Google Scholar
Boyle, J. E. & Smith, D. C., 1975. Biochemical interactions between the symbionts of Convoluta roscoffensis. Proceedings of the Royal Society (B), 189, 121135.Google Scholar
Christiansen, H. N., 1975. Biological Transport, 2nd edition. 514 pp. Massachusetts: Benjamin.Google Scholar
Doonan, S. A. & Gooday, G. W., 1982. An ecological study of symbiosis in Convoluta roscoffensis. Marine Ecology-Progress Series, 8, 6973.CrossRefGoogle Scholar
Douglas, A. E., 1981. Symbiosis in Convoluta roscoffensis. Ph.D. Thesis, University of Aberdeen.Google Scholar
Douglas, A. E., 1983. Establishment of the symbiosis in Convoluta roscoffensis. Journal of the Marine Biological Association of the United Kingdom, 63, 419434.CrossRefGoogle Scholar
Florkin, M. & Duchateau, G., 1943. Les formes du système enzymatique de l'uricolyse et l'évolution du catabolisme purique chez les animaux. Archives Internationales de physiologie, 53, 267307.Google Scholar
Gooday, G. W., 1970. A physiological comparison of the symbiotic alga Platymonas convolutae and its free-living relatives. Journal of the Marine Biological Association of the United Kingdom, 50, 199208.Google Scholar
Hansen, D. L. & Bush, E. T., 1967. Improved solubilisation procedures for liquid scintillation counting of biological materials. Analytical Biochemistry, 18, 320332.CrossRefGoogle Scholar
Holligan, P. M. & Gooday, G. W., 1975. Symbiosis in Convoluta roscoffensis. Symposia of the Society for Experimental Biology, no. 29, 205227.Google Scholar
Hyman, L., 1951. The Invertebrates, vol. 2. Platyhelminthes and Rynchocoela. The Acoelomate Bilateria. 550 pp. New York: McGraw-Hill.Google Scholar
Keeble, F., 1910. Plant Animals: A Study in Symbiosis. 163 pp. Cambridge University Press.Google Scholar
Keeble, F. & Gamble, F. W., 1907. The origin and nature of the green cells of Convoluta roscoffensis. Quarterly Journal of Microscopical Science, 51, 167219.Google Scholar
Lowry, O. H., Rosebrough, N. J., Farr, A. L. & Randall, R. J., 1951. Protein measurement with Folin phenol reagent. Journal of Biological Chemistry, 193, 265275.CrossRefGoogle ScholarPubMed
Mcnabb, R. A. & Mcnabb, F. M. A., 1980. Physiological chemistry of uric acid: solubility, colloid and ion-binding properties. Comparative Biochemistry and Physiology, 67 A, 2734.CrossRefGoogle Scholar
Pickering, W. R. & Wood, R. A., 1972. The uptake and incorporation of purines by wild-type Saccharomyces cerevisiae and mutant resistant to 4-aminopyrazolo-(3,4-d)-pyrimidine. Biochimica et biophysica acta, 264, 4558.CrossRefGoogle Scholar
Provasoli, L., 1968. Media and prospects for the cultivation of marine algae. In Cultures and Collections of Algae (ed. Watanabe, A. and Hattori, A.), pp. 6375. The Japanese Society of Plant Physiologists.Google Scholar
Provasoli, L., Yamasu, T. & Manton, I., 1968. Experiments on the resynthesis of the symbiosis in Convoluta roscoffensis with different flagellate cultures. Journal of the Marine Biological Association of the United Kingdom, 48, 465478.CrossRefGoogle Scholar
Roush, A. H., 1961. Crystallisation of purines in the vacuole of Candida utilis. Nature, London, 190, 449.CrossRefGoogle ScholarPubMed
Roush, A. H., Questiaux, L. M. & Domnas, A. J., 1959. The active transport and metabolism of purines in the yeast Candida utilis. Journal of Cellular and Comparative Physiology, 54, 275286.CrossRefGoogle ScholarPubMed
Simmons, J. E., 1970. Nitrogen metabolism in Platyhelminthes. In Comparative Biochemistry of Nitrogen Metabolism, vol. 1 (ed. Campbell, J. W.), pp. 6789. Academic Press.Google Scholar
Vogels, G. D. & Drift, C. van der, 1976. Degradation of purines and pyrimidines by microorganisms. Bacteriological Reviews, 40, 403468.CrossRefGoogle ScholarPubMed