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- Hydrolytic enzymes in Paracoccidioides brasiliensis - ecological aspects
- Bruno Benoliel, Fabrício B.M. Arraes, Viviane Castelo-Branco Reis, Saulo J.L. de Siqueira, Nádia S. Parachin and Fernando A.G. Torres
- Laboratório de Biologia Molecular, Departamento de Biologia Celular, Universidade de Brasília,
- 70910-900 Brasília, DF, Brasil
- Corresponding author: F.A.G. Torres
- E-mail: [email protected]
- Genet. Mol. Res. 4 (2): 450-461 (2005)
- Received January 18, 2005
- Accepted May 5, 2005
- Published June 30, 2005
ABSTRACT. Paracoccidioides brasiliensis is a thermally dimorphic fungus that causes paracoccidioidomycosis. The yeast form of this pathogen is found in the animal host whereas the mycelial form is recovered from living and non-living organic material. The sole carbon source available in these habitats is represented by polysaccharides from the plant cell wall. Hydrolytic enzymes are necessary to convert these polymers into simple sugars for fungal metabolism. We report on the presence of ortholog genes of hydrolytic enzymes identified in the P. brasiliensis transcriptome and on hydrolytic activities in supernatants of induced P. brasiliensis cultures of mycelium and yeast cells. Enzymatic assays have shown cellulase and xylanase activities, both being higher in mycelium than in the yeast form. Amylase and chitinase activities were detected only in mycelium. Data so far reinforce the idea that mycelial P. brasiliensis is a saprobe.
Key words: Paracoccidioides brasiliensis, Hydrolytic enzymes, Saprophytic, Ecology
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