Mutagenesis of Aspergillus oryzae IPT-301 to improve the production of β-fructofuranosidase

• Published in: Brazilian journal of microbiology 2010, Vol.41 (1)
• Main Authors: Maresma, Beatriz Guilarte(Instituto Cubano de Investigaciones Azucareras), Castillo, Boris Gutarra(Universidade de São Paulo Instituto de Pesquisas Tecnológicas Laboratório de Biotecnologia Industrial), Fernández, Rubén Cuervo(Instituto Cubano de Investigaciones Azucareras), Silva, Elda Sabino da(Universidade de São Paulo Instituto de Pesquisas Tecnológicas Laboratório de Biotecnologia Industrial), Maiorano, Alfredo Eduardo(Universidade de São Paulo Instituto de Pesquisas Tecnológicas Laboratório de Biotecnologia Industrial), Rodrigues, Maria Filomena de Andrade(Universidade de São Paulo Instituto de Pesquisas Tecnológicas Laboratório de Biotecnologia Industrial)
• Format: Article
• Language: English
• Subjects: Aspergillus oryzae; Fructooligosaccharides; Fructosyltransferase; Mutagenesis; UV irradiation; β-fructofuranosidase
• ISSN: 1517-8382; 1678-4405

Aspergillus oryzae IPT-301, previously reported as a β-fructofuranosidase producing microorganism, was successfully mutated using UV irradiation at 253.7 nm followed by the screening of survivors resistant to certain stress conditions. Strains were first subjected to the β-fructofuranosidase activity assay using a portion from the colony grown in Petri dish as the enzyme source. Seven mutants with fructofuranosidase activity values relative to the parent culture between 140 -190% were selected from survivors grown at temperature of 40ºC or 0.018% (w/v) sodium dodecyl sulfate concentration. They were cultivated on a rotary shaker to characterize mycelium and extracellular fructosyltransferase activities. Three mutants named IPT-745, IPT-746 and IPT-748 showed the highest amount of mycelium activity whose values increased 1.5 -1.8 fold, compared with the parent strain. It was found that more than 55% of total enzyme activity (mycelium- plus extracellular- activity) from these strains was detected in the mycelium fraction. Only one mutant, IPT-747, exceeded the amount of extracellular enzyme exhibited by the parent strain (1.5 times). This mutant also showed the highest value of total fructosyltransferase activity.