Two alternative pathways for substrate assimilation byMucor circinelloides
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Transition of an oleaginous strain ofMucor circinelloides from mycelial to yeast-like form was studied in conditions favoring lipogenesis. In culture media with citric acid as the sole carbon source at concentrations of 7.5 and 10 g/L (C/N ratio of 26 and 35, respectively), the mold accumulated significant quantities of lipid. At a higher citric acid concentration liposynthesis was inhibited and the fermentation mechanism decreased the high substrate concentration in the culture media. Under these conditions yeast-like morphogenesis was observed. In the yeast-like cells, biosynthesis of linoleic and γ-linolenic acid was inhibited. In contrast, no significant changes were observed in the biosynthesis of palmitoleic acid whereas the concentration of oleic acid was increased in the storage lipids of yeast-like cells.
KeywordsCitric Acid Cellular Lipid High Substrate Concentration Citrate Concentration Mycelial Form
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- AFNOR:Recueil de normes Francaises des corps gras—graines oleagineuses et produits derives. 3eme ed. NF T 60-233, p. 95 (1984).Google Scholar
- Aggelis G., Ratomahenina R., Arnaud A., Galzy P., Martin-Privat P., Perraud J.P., Pina M., Graille J.: Etude de l'influence des conditions de culture sur la teneur en acide gamma linolenique de souches deMucor.Oleagineux 43, 311–318 (1988).Google Scholar
- Aggelis G.: Etude de la production d'acide gamma linolenique par de Phycomycetes (Mucorales).PhD Thesis. Université de Montpellier II—USTL 1989.Google Scholar
- Aggelis G., Komaitis M., Papanikolaou S., Papadopoulos G.: A mathematical model for the study of lipid accumulation in oleaginous microorganisms. II. Study of cellular lipids ofMucor circinelloides during growth on a vegetable oil.Grasas y Aceites 46, 245–250 (1995).Google Scholar
- Evans C.T., Ratledge C.: The physiological significance of citric acid in the control of metabolism in lipid accumulating yeasts.Biotechnol. Genet. Eng. Rev. 3, 349–374 (1985).Google Scholar
- Holdsworth J.E., Ratledge C.: Lipid turnover in oleaginous yeasts.J. Gen. Microbiol. 134, 339–346 (1988).Google Scholar