Immobilization of Carboxypeptidase A into Modified Chitosan Matrixes by Covalent Attachment.

Carboxypeptidase A (CPA) is a metalloexopeptidase that catalyzes the hydrolysis of the peptide bonds that are adjacent to the C-terminal end of a polypeptide chain. The enzyme preferentially cleaves over C-terminal L-amino acids with aromatic or branched side chains. This is of main importance for food industry because it can be employed for manufacturing functional foods from different protein sources with reduced hydrophobic amino acid content for patients with deficiencies in the absorption or digestion of the corresponding amino acids.

Operational and Thermal Stability Analysis of Thermomyces lanuginosus Lipase Covalently Immobilized onto Modified Chitosan Supports.

The aim of this paper was to evaluate different strategies of chitosan activation using cross-linking reagent like glycidol, epichlorohydrin, and glutaraldehyde for Thermomyces lanuginosus lipase (TLL) immobilization. Operational activity and stability by esterification of oleic acid with ethanol and thermal inactivation using these derivatives were investigated. Derivative obtained by sequentially activation with glycidol, ethylenediamine, and glutaraldehyde and subsequent TLL immobilization showed the best performance, with high hydrolytic activity value.

Immobilization of CALB on activated chitosan: Application to enzymatic synthesis in supercritical and near-critical carbon dioxide.

The objective of this new paper was to evaluate the enzymatic esterification reaction conducted in supercritical or near-critical CO, catalyzed by immobilized lipase B from (CALB). The biocatalyst was prepared through the immobilization of CALB by covalent attachment using chitosan sequentially activated with Glycidol, ethylenediamine (EDA) and glutaraldehyde as support. In order to determine the best operational conditions of the esterification reaction (1: 1 (alcohol-acid); biocatalyst content, 10% (by substrate mass); 45 °C), an experimental design (2) was conducted to evaluate the effects of the following parameters: alcohol to oil molar ratios, reaction time and temperature.