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0172-8083 (Print) Journal Article; The exoproteome of the fungus Fusarium graminearum grown on glucose and on hop (Humulus lupulus, L.) cell wall has been investigated. The culture medium was found to contain a higher quantity of proteins and the proteins are more diverse when the fungus is grown on cell wall. Using both 1D and 2D electrophoresis followed by mass spectrometry analysis and protein identification based on similarity searches, 84 unique proteins were identified in the cell wall-grown fungal exoproteome. Many are putatively implicated in carbohydrate metabolism, mainly in cell wall polysaccharide degradation. The predicted carbohydrate-active enzymes fell into 24 different enzymes classes, and up to eight different proteins within a same class are secreted. This indicates that fungal metabolism becomes oriented towards synthesis and secretion of a whole arsenal of enzymes able to digest almost the complete plant cell wall. Cellobiohydrolase is one of the only four proteins found both after growth on glucose and on plant cell wall and we propose that this enzyme could act as a sensor of the extracellular environment. Extensive knowledge of this very diverse F. graminearum exoproteome is an important step towards the full understanding of Fusarium/plants interactions.

International audience; The osmotolerant and cell wall properties of the two most studied wild-type Zygosaccharomyces rouxii strains (CBS 732 and ATCC 42981) were examined. Differences in their (1) tolerance to high salt content in the medium, (2) resistance to the lysing enzymes Lyticase and Zymolyase, (3) cell-wall polymer content and (4) cell wall micromorphology suggested that the less osmotolerant CBS 732 strain possesses a more rigid cell wall than the more osmotolerant ATCC 42981, whose cell wall seems to be more flexible and elastic.