Abstract
Cryptococcus neoformans, an encapsulated yeast that is an opportunistic pathogen of AIDS patients, produced and secreted mannitol when incubated with an appropriate carbon source. Glucose, fructose, and mannose were good growth substrates and were converted to mannitol. Maltose and xylose were good growth substrates but were not converted to mannitol. Cells of C. neoformans that were grown on a non-mannitol-generating carbon source, such as peptone or xylose, were able to convert glucose to mannitol only after a prolonged lag period in the presence of glucose. It was concluded that the enzymes of the mannitol biosynthetic pathway were not constitutively expressed but were induced in response to glucose or to a glucose metabolite. Enzymes required to catabolize mannitol, however, were constitutively expressed. The production of mannitol was inhibited by anaerobiosis, by the respiratory poison rotenone, and by polyethylenesulfonate, a specific inhibitor of fungal NADP-dependent dehydrogenases. When cells were incubated with deuterated glucose, the deuterium content of the mannitol produced was much lower than that of the glucose precursor, indicating that the glucose was diluted by an intracellular pool of an intermediate. We had previously shown that C. neoformans contains a large intracellular pool of glucose 6-phosphate, and we now conclude that this pool of glucose 6-phosphate is metabolically active.
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- André L., Hemming A., Adler L. Osmoregulation in Saccharomyces cerevisiae. Studies on the osmotic induction of glycerol production and glycerol-3-phosphate dehydrogenase (NAD+) FEBS Lett. 1991 Jul 29;286(1-2):13–17. doi: 10.1016/0014-5793(91)80930-2. [DOI] [PubMed] [Google Scholar]
- Blomquist C. H., Snyder B. D., Niehaus W. G. Improved enzymatic method for determining mannitol and its application to dog serum after mannitol infusion. J Clin Chem Clin Biochem. 1981 Mar;19(3):139–143. doi: 10.1515/cclm.1981.19.3.139. [DOI] [PubMed] [Google Scholar]
- Foreman J. E., Niehaus W. G., Jr Zn2+-induced cooperativity of mannitol-1-phosphate dehydrogenase from Aspergillus parasiticus. J Biol Chem. 1985 Aug 25;260(18):10019–10022. [PubMed] [Google Scholar]
- Niehaus W. G., Jr, Dilts R. P., Jr Purification and characterization of mannitol dehydrogenase from Aspergillus parasiticus. J Bacteriol. 1982 Jul;151(1):243–250. doi: 10.1128/jb.151.1.243-250.1982. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Niehaus W. G., Jr, Jiang W. P. Nitrate induces enzymes of the mannitol cycle and suppresses versicolorin synthesis in Aspergillus parasiticus. Mycopathologia. 1989 Sep;107(2-3):131–137. doi: 10.1007/BF00707550. [DOI] [PubMed] [Google Scholar]
- Niimi M., Tokunaga M., Nakayama H. Regulation of mannitol catabolism in Candida albicans: evidence for cyclic AMP-independent glucose effect. J Med Vet Mycol. 1986 Jun;24(3):211–217. doi: 10.1080/02681218680000311. [DOI] [PubMed] [Google Scholar]
- Perfect J. R., Lang S. D., Durack D. T. Chronic cryptococcal meningitis: a new experimental model in rabbits. Am J Pathol. 1980 Oct;101(1):177–194. [PMC free article] [PubMed] [Google Scholar]
- Quain D. E., Boulton C. A. Growth and metabolism of mannitol by strains of Saccharomyces cerevisiae. J Gen Microbiol. 1987 Jul;133(7):1675–1684. doi: 10.1099/00221287-133-7-1675. [DOI] [PubMed] [Google Scholar]
- Wong B., Brauer K. L., Tsai R. R., Jayasimhulu K. Increased amounts of the Aspergillus metabolite D-mannitol in tissue and serum of rats with experimental aspergillosis. J Infect Dis. 1989 Jul;160(1):95–103. doi: 10.1093/infdis/160.1.95. [DOI] [PubMed] [Google Scholar]
- Wong B., Perfect J. R., Beggs S., Wright K. A. Production of the hexitol D-mannitol by Cryptococcus neoformans in vitro and in rabbits with experimental meningitis. Infect Immun. 1990 Jun;58(6):1664–1670. doi: 10.1128/iai.58.6.1664-1670.1990. [DOI] [PMC free article] [PubMed] [Google Scholar]