Objective
Engineering of metabolic fluxes in filamentous fungi is expected to bring major improvements in the production of metabolises and enzymes. This proposal is focused on trehalose and glycerol metabolism which have been proposed to control glycolytic flux e.g. through inhibition of hexokinase by trehalose-6phosphate synthase and regulation by glycerol-3-phosphate of the levels of fructose-2,6-biphosphate, a potent activator of phosphofructokinase. In addition to these proposed functions, trehalose and glycerol may play an important role in stress adaptation and morphogenesis of fungi. Trehalose is synthesized in phases of nutrient starvation, dessication, and exposure to heat-shock and is particularly present in dormant spores. Although filamentous fungi produce other polyols, glycerol acts as the primary compatible solute in response to high osmolarity and low temperature. Furthermore, high levels of glycerol are accumulated during spore germination and infection structure differentiation and seem to participate in the establishment of morphogenesis in filamentous fungi. Therefore, a better understanding of glycerol and trehalose metabolism should not only yield applications in the field of metabolic engineering but also in the design of innovative strategies to prevent growth of pathogenic and food spoilage fungi.
The main objective of this proposal is therefore to decipher the functions of trehalose and glycerol in fungi with respect to the regulation of the glycolytic flux, the sensitivity to a variety of stresses and the morphogenetic program.
Two model organisms have been chosen. Aspergillus nidulans serves as an appropriate model for fungal species involved in the production of economically important metabolises and enzymes (A. niger), in human disease (A. fumigatus), and in food spoilage (Aspergillus sp. and Penicillium sp.). Magnaporthe grisea, the causal agent of rice blast, provides a plant pathogen model, since its infection structures (appressoria) accumulate high glycerol levels. Preventing glycerol biosynthesis or accumulation in phytopathogens is expected to provide an important basis for the development of new antifungals in crop protection. The major genes involved in glycerol biosynthesis and efflux will therefore be identified in A. nidulans and M grisea and used, together with the already available genes of trehalose metabolism, to construct strains impaired in glycerol and trehalose metabolism, whereas Saccharomyces cerevisiae mutants and genes will be used to identify functional similarities and differences. Engineered strains will be evaluated in tests on metabolic fluxes in the bioreactor environment, on osmoadaptation, morphogenesis, pathogenicity, low and high temperature sentivity, and pH and antifungal sensitivity.
The network of three academic and two industrial laboratories has excellent expertise in the genetics of filamentous fungi and yeasts, in the biochemistry, physiology and molecular genetics of sugar and polyol metabolism and in the study of phytopathogenic fungi. The industrial partners foresee applications of this research in the field of antifungal development and improvement of fungal strains and processes used in the food and in the fermentation industry.
Fields of science (EuroSciVoc)
CORDIS classifies projects with EuroSciVoc, a multilingual taxonomy of fields of science, through a semi-automatic process based on NLP techniques.
CORDIS classifies projects with EuroSciVoc, a multilingual taxonomy of fields of science, through a semi-automatic process based on NLP techniques.
- natural sciencesbiological sciencesgenetics
- natural sciencesbiological sciencesmolecular biologymolecular genetics
- natural sciencesbiological sciencesmicrobiologymycology
- natural sciencesbiological sciencesbiochemistrybiomoleculeslipids
- natural sciencesbiological sciencesbiochemistrybiomoleculesproteinsenzymes
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Topic(s)
Call for proposal
Data not availableFunding Scheme
CSC - Cost-sharing contractsCoordinator
75724 PARIS
France