Summary
A heretofore undescribed minute-rough colonial variant has been isolated from cultures of a red, adenine auxotroph ofCandida albicans, strain WC—7. The variant has been detected only in WC—7 populations which are propagated at 37° C on very low concentrations of adenine. It produces colonies much smaller than those of WC—7 at both 25° C and 37° C on defined media containing either ammonium ion or casein hydrolysate as nitrogen sources. On ammonium nitrogen, young variant colonies are smooth and contain only typical yeast cells. While colonies which grow at 37° C retain these characteristics upon extended incubation, those growing at 25° C progressively roughen due to extensive development of pseudohyphae as the glucose levels in their vicinities decline. Under comparable conditions, colonies of the parental strain WC—7 remain smooth and free of pseudohyphae, Supplementing the medium with large amounts of glucose, intermediates of the tricarboxylic acid cycle or any one of several amino acids biosynthetically derived from intermediates of oxidative respiration prevents formation of pseudohyphae by the variant without significantly affecting its growth rate. Genetically, the variant is unstable and reverts frequently to a stable, rapidly growing form apparently identical to strain WC—7. Evidence is presented indicating that, under certain circumstances, variant cells can exercise a contact-inhibition of the growth of their revertants. Possible physiological bases of the variriant's cultural properties are discussed.
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References
Alvarez, A. &Mackinnon, J. E. 1957. Lethal variant ofCandida albicans, a petite colonie mutant. Science126: 399–400.
Bianchi, D. E. 1961a. A small-colony variant ofCandida albicans. Amer. J. Bot.48: 499–503.
Bianchi D. E. 1961b. Small colony variant inCandida albicans. J. Bact.82: 101–105.
Bish, J. T. &Sarachek, A. 1967. Influences of temperature and adenine concentration upon the cultural instability of a red adenine auxotroph ofCandida albicans. Mycologia59: 671–688.
Cirillo, V. P., Wilkins, P. O. &Anton, J. 1963. Sugar transport in a psychrophilic yeast. J. Bact.86: 1259–1264.
Ephrussi, B. 1953. Nucleo-cytoplasmic Relations in Microorganisms. Oxford: Clarendon Press.
Harris, G. 1958. Nitrogen Metabolism. In: The Chemistry and Biology of Yeasts. Ed. A. H. Cook. Pp. 437–534. New York: Academic Press.
Nickerson, W. J. &Mankowski, Z. T. 1953. Role of nutrition in the maintenance of the yeast-shape inCandida. Amer. J. Bot.40: 584–592.
Ogur, M. &St. John, R. 1956. A differential and diagnostic plating method for population studies of respiration deficiency in yeast. J. Bact.72: 500–504.
Sarachek, A. 1964. Promotion or retardation of the growth of adenine auxotrophs ofCandida albicans by purines, pyrimidines, and nucleosides. Antonie van Leeuwenhoek, J. Microbiol. and Serol.30: 289–302.
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Ireland, R., Sarachek, A. A unique minute-rough colonial variant of Candida albicans. Mycopathologia et Mycologia Applicata 35, 346–360 (1968). https://doi.org/10.1007/BF02050750
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DOI: https://doi.org/10.1007/BF02050750