| Autor: |
Freitas M; Health Sciences School, University of Brasília, Brasília 70910-900, Brazil., Souza P; Health Sciences School, University of Brasília, Brasília 70910-900, Brazil., Cardoso S; Health Sciences School, University of Brasília, Brasília 70910-900, Brazil., Cruvinel K; Health Sciences School, University of Brasília, Brasília 70910-900, Brazil., Abrunhosa LS; Health Sciences School, University of Brasília, Brasília 70910-900, Brazil., Ferreira Filho EX; Institute of Biological Sciences, University of Brasília, Brasília 70910-900, Brazil., Inácio J; School of Pharmacy and Biomolecular Sciences, University of Brighton, Brighton BN2 4GJ, UK., Pinho DB; Institute of Biological Sciences, University of Brasília, Brasília 70910-900, Brazil., Pessoa A; Department of Biochemical and Pharmaceutical Technology, University of São Paulo, São Paulo 05508-000, Brazil., O Magalhães P; Health Sciences School, University of Brasília, Brasília 70910-900, Brazil. |
| Abstrakt: |
l-asparaginase is an enzyme used as treatment for acute lymphoblastic leukemia (ALL) due to its ability to hydrolyze l-asparagine, an essential amino acid synthesized by normal cells unlike neoplastic cells. The adverse effects of l-asparaginase formulations are associated with its glutaminase activity and bacterial origin; therefore, it is important to find new sources of l-asparaginase-producing eukaryotic microorganisms with low glutaminase activity. This work evaluated the biotechnological potential of filamentous fungi isolated from Brazilian Savanna soil and plants for l-asparaginase production. Thirty-nine isolates were screened for enzyme production using the plate assay, followed by measuring enzymatic activity in cells after submerged fermentation. The variables influencing l-asparaginase production were evaluated using Plackett-Burman design. Cell disruption methods were evaluated for l-asparaginase release. Penicillium sizovae 2DSST1 and Fusarium proliferatum DCFS10 showed the highest l-asparaginase activity levels and the lowest glutaminase activity levels. Penicillium sizovae l-asparaginase was repressed by carbon sources, whereas higher carbon concentrations enhanced l-asparaginase by F. proliferatum . Maximum enzyme productivity, specific enzyme yield and the biomass conversion factor in the enzyme increased after Plackett-Burman design. Freeze-grinding released 5-fold more l-asparaginase from cells than sonication. This study shows two species, which have not yet been reported, as sources of l-asparaginase with possible reduced immunogenicity for ALL therapy. |
