TITLE:
Immobilization of Lipase from Candida rugosa on Mesoporous MCM 41
AUTHORS:
Roberto Rodrigues de Souza, Renata D. M. Ferreira
KEYWORDS:
Immobilization, Lipase, Mesoporous
JOURNAL NAME:
Journal of Biosciences and Medicines,
Vol.2 No.4,
June
27,
2014
ABSTRACT: The use of enzymatic route for production
of biofuels is growing up due the mild reaction conditions that this method
provides, as well as reducing SOx emission. To reduce costs, it’s necessary to
immobilize the enzyme, making possible to use it continuously as biocatalyst.
The aim of this work was to measure the influence of the mass of support and pH
used for immobilization of commercial lipase from Candida rugosa acquired by
Sigma laboratory. The immobilization method chosen was adsorption on mesoporous
and hydrophobic support MCM 41, this has been treated with nitric acid 10% v/v
to remove any organic residue. Then, 20 ml of enzymatic solution in phosphate
buffer (pH 6.0, 7.0 and 8.0; 50 mM) and 1 g/L was placed under constant
stirring with 0.30 and 0.45 g of support. Aliquots were taken from the reaction
medium and analyzed by spectrophotometry at 10 minutes intervals. A volume of
0.2 ml of supernatant was put with 1.8 ml of substrate p-NFL at 0.18 g/L, and
the absorbance at 410 nm was analyzed. In four cases there was a sharp
reduction of supernatant’s activity at first 10 minutes, that ratifies the big
affinity of the enzyme for the support and the negative influence of pH about
the activity. Using the calibration curve, it was possible to calculate the
final activity of each immobilization batch. This work suggests the occurrence
of diffusional effects, which means that the enzyme mobility was restricted due
the excessive amount of support, and then, it lost a part of accessibility to
substrate, reflecting in not expressive activity values, and changing the state
of ionization of the components of the system.