Resumo

ROMERO VARGAS, Gissell Astrid  e  REYES CUELLAR., Julia Constanza. Sucrose hydrolysis by invertase of Saccharomyces cerevisiae immobilized on cobalt ferrite magnetic nanoparticles. Acta Agron. [online]. 2019, vol.68, n.2, pp.115-125. ISSN 0120-2812.  https://doi.org/10.15446/acag.v68n2.78340.

An alternative method for the hydrolysis of sucrose to glucose and fructose is ß-D-fructofuranosidase of Saccharomyces cerevisiae immobilized on cobalt ferrite magnetic nanoparticles (NPM-CoFe2O4). This methodology allows the reuse of the biological entity. The literature suggests that the immobilization of enzyme modifies its activity, for this reason the changes in catalytic properties of the immobilized enzyme were quantified to know the effectiveness of this system at laboratory scale. The magnetic nanoparticles were synthesized by the polyol reduction method and were characterized by X-ray Diffraction, Vibrating Sample Magnetometry and Scanning Electron Microscopy and Transmission Electron Microscopy. The nanoparticles were coated with chitosan and activated with glutaraldehyde, which was used as a linker for coupling the ß-D-fructofuranosidase on the nanostructure. The bio-nanoparticles were characterized by Fourier Transformed Infrared Spectroscopy and the amount of immobilized enzyme and the immobilization yield were determined by the spectrophotometric Bradford method. The catalytic behavior of the enzyme as a pH function and temperature was investigated. The optimum operational pH was 0.5 higher for immobilized enzymes than free enzymes. The optimum operational temperature was 50°C for free and immobilized enzymes. Interestingly, V máx decreases by 2.96% upon immobilization. The value of K m increases by a factor of 1.7 upon immobilization. The bio-nanoparticles retained 95.89 and 91.79% of its initial activity in the second and third cycle of use.

Palavras-chave : hydrolysis; immobilized enzyme; food industry; nanotechnology; sucrose.

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