Application of Spectrogel clay as a support for immobilization of lipase from Burkholderia cepacia

The interest in maximizing the production of ethyl esters in a sustainable way and with lower energy costs has increased the use of immobilized enzymes as catalysts. This study aimed to apply the commercial clay Spectrogel® as a support for the immobilization of lipase from Burkholderia cepacia by adsorption and covalent bonding methods. The immobilizations were carried out using a 2³ factorial design to study the effects of the activity offered (U g⁻¹), pH, and the molar concentration of the enzyme solution buffer (mol L⁻¹) on the enzyme activity obtained (U g⁻¹). From the statistical analysis of the results, the best conditions for immobilization were pH 7.0 and 0.1 mol L⁻¹ for both tested immobilization methods, with the best offered activity being 5709 and 7600 U g⁻¹. The activities obtained were 1219.81 ± 7.51 and 1274.89 ± 14.99 U g⁻¹ for adsorption and covalent bonding, respectively. The biocatalysts exhibited protein leaching of 33.55 ± 1.08% and 19.44 ± 2.43% when immobilized by adsorption and covalent bonding, respectively. The optimal activity temperature and thermal stability were obtained at 40°C. Additionally, the immobilization of lipase in Spectrogel® by both methods was efficient, showing higher thermal stability than the free enzyme. Thus, this work contributed scientifically to the development of a new and economical biocatalyst for ethyl ester production.