Screening of endophytic fungi from cactus of the Brazilian tropical dry forest according to their L-asparaginase activity
Santos M.G.S., Bezerra J.D.P., Svedese V.M., Sousa M.A., Silva D.C.V., Maciel M.H.C., Paiva L.M., Porto A.L.F., Souza-Motta C.M.
L-asparaginase is an enzyme that is used as a chemotherapeutic agent for the treatment of human cancer. The endophytic fungi have great potential in the production of new bioactive substances. However, there are no data on the production of this enzyme by these fungi in Brazil. Endophytic fungi have been isolated from the cactus Cereus jamacaru and selected for production of L-asparaginase in solid and liquid media. In solid medium, the formation of a halo around the fungal colony was observed, indicating enzyme production capacity. Enzyme production was investigated in liquid medium by inoculating the fungal cultures and the enzyme activity was determined by Nessler’s technique. Of the 44 endophytic fungi, 30 showed a halo of degradation, and 19 produced L-asparaginase in liquid medium. Aspergillus ochraceus URM 6885 (19.63 U/ml), A. japonicus URM 6872 (23.37 U/ml), A. terreus URM 6888 (28.20 U/ml), A. sydowii URM 6866 (29.02 U/ml), Fusarium oxysporum URM 6815 (16.75 U/ml), Gibberella fujikuroi var. fujikuroi URM 6816 (26.93 U/ml), and Penicillium brevicompactum URM 6833 (26.54 U/ml) had the greatest ability to synthesize L-asparaginase in liquid medium. The endophytic fungi isolated from the cactus C. jamacaru have great biotechnological potential and are capable of producing the L-asparaginase enzyme.
Keywords: Antitumoral enzyme, cactaceae, chemotherapeutic agent.
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