Immobilization of β-Galactosidase by Encapsulation of Enzyme-Conjugated Polymer Nanoparticles Inside Hydrogel Microparticles

Correlations between in vitro gastrointestinal digestion of β-galactosidase/carboxymethylchitosan-silica dosage powder and its physicochemical properties

Oral administration of β-galactosidase, which alleviate lactose intolerance symptoms, is challenging due to its instability throughout the gastrointestinal tract. The objective of this work was to make correlations between the in-vitro digestion and chemical characteristics of a β-galactosidase/carboxymethylchitosan-silica biocatalyst powder. This was obtained by a one-pot silica gel route assisted by carboxymethyl chitosan, using maltose as lyoprotectant. The chemical characterization allowed to understand as was modulated the calcium incorporation, through electrostatic interactions and as maltose protects the enzyme from agglomeration, by vitrification and formation of hydrogen bonds. The formulated biocatalyst could be a complement of silicon and calcium, in turn, it preserves 96 % and 63 % of the enzymatic activity compared with the biocatalyst control (without simulated digestion), in the gastric and intestinal phases, respectively. This activity was even greater than that observed in the commercial products evaluated in these phases. Likewise, the biocatalyst obtained retained its activity after 12 months of storage at 25 °C and it did not present cytotoxicity in cells derived from human colon epithelial mucosa (NCM460) under the conditions and concentrations evaluated. These results make this biocatalyst in an excellent candidate for release of this enzyme. Therefore, it could be useful for lactose-intolerant people.

Enzyme Immobilization and Co-Immobilization: Main Framework, Advances and Some Applications

Enzymes are outstanding (bio)catalysts, not solely on account of their ability to increase reaction rates by up to several orders of magnitude but also for the high degree of substrate specificity, regiospecificity and stereospecificity. The use and development of enzymes as robust biocatalysts is one of the main challenges in biotechnology. However, despite the high specificities and turnover of enzymes, there are also drawbacks. At the industrial level, these drawbacks are typically overcome by resorting to immobilized enzymes to enhance stability. Immobilization of biocatalysts allows their reuse, increases stability, facilitates process control, eases product recovery, and enhances product yield and quality. This is especially important for expensive enzymes, for those obtained in low fermentation yield and with relatively low activity. This review provides an integrated perspective on (multi)enzyme immobilization that abridges a critical evaluation of immobilization methods and carriers, biocatalyst metrics, impact of key carrier features on biocatalyst performance, trends towards miniaturization and detailed illustrative examples that are representative of biocatalytic applications promoting sustainability.