| Summary: | <span style="font-variant: small-caps;">l</span>-asparaginase is an enzyme used as treatment for acute lymphoblastic leukemia (ALL) due to its ability to hydrolyze <span style="font-variant: small-caps;">l</span>-asparagine, an essential amino acid synthesized by normal cells unlike neoplastic cells. The adverse effects of <span style="font-variant: small-caps;">l</span>-asparaginase formulations are associated with its glutaminase activity and bacterial origin; therefore, it is important to find new sources of <span style="font-variant: small-caps;">l</span>-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 <span style="font-variant: small-caps;">l</span>-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 <span style="font-variant: small-caps;">l</span>-asparaginase production were evaluated using Plackett–Burman design. Cell disruption methods were evaluated for <span style="font-variant: small-caps;">l</span>-asparaginase release. <i>Penicillium sizovae</i> 2DSST1 and <i>Fusarium proliferatum</i> DCFS10 showed the highest <span style="font-variant: small-caps;">l</span>-asparaginase activity levels and the lowest glutaminase activity levels. <i>Penicillium sizovae</i> <span style="font-variant: small-caps;">l</span>-asparaginase was repressed by carbon sources, whereas higher carbon concentrations enhanced <span style="font-variant: small-caps;">l</span>-asparaginase by <i>F. proliferatum</i>. 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 <span style="font-variant: small-caps;">l</span>-asparaginase from cells than sonication. This study shows two species, which have not yet been reported, as sources of <span style="font-variant: small-caps;">l</span>-asparaginase with possible reduced immunogenicity for ALL therapy.
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