Permeabilization of Saccharomyces fragilis IZ 275 cells with ethanol to obtain a biocatalyst with lactose hydrolysis capacity

Luiz Rodrigo Ito Morioka, Geyci de Oliveira Colognesi, Hélio Hiroshi Suguimoto


The permeabilization was used to transform microorganisms in cell biocatalysts with high enzymatic activity. The Saccharomyces fragilis IZ 275 yeast cells were permeabilized with ethanol, as permeabilizing agent. To optimize the permeabilization conditions were used the design of Box-Behnken 15 trials (3 central points). The independent variables and their levels were ethanol (29, 32 and 35%), temperature (15, 20 and 25°C) and time (15, 20 and 25 min). The answer (Y) function has beta-galactosidase activity (U mg-1). The optimum conditions for obtaining a high enzymatic activity were observed in 35% ethanol concentration, temperature 15ºC and 20 min. treatment time. The maximum activity of the enzyme beta-galactosidase obtained was 10.59 U mg-1. The permeabilization of the S. fragilis IZ 275 cells was efficient.



permeabilizing agent; beta-galactosidase; microbial biotechnology; optimal conditions

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ISSN 1679-9283 (impresso) e ISSN 1807-863X (on-line) e-mail:


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