Immobilization of β-galactosidase from Bacillus licheniformis for application in the dairy industry

• Published in: Applied microbiology and biotechnology 2021-05, Vol.105 (9), p.3601-3610
• Main Authors: Kuribayashi, Lilian Mayumi, do Rio Ribeiro, Victoria Pires, de Santana, Ricardo Corrêa, Ribeiro, Eloízio Júlio, dos Santos, Milla Gabriela, Falleiros, Larissa Nayhara Soares Santana, Guidini, Carla Zanella
• Format: Article
• Language: English
• Subjects: Bacillus licheniformis; Batch reactors; Biocatalysts; Biomedical and Life Sciences; Biotechnologically Relevant Enzymes and Proteins; Biotechnology; Buffer solutions; Catalysts; Crosslinking; Dairy industry; Dairy products; Enzymatic activity; Enzyme activity; Enzymes; Food industry; Food processing industry; Galactosidase; Glutaraldehyde; Immobilization; Industrial development; Intolerance; Ion exchange; Ion exchange resins; Ionic strength; Lactose; Life Sciences; Microbial Genetics and Genomics; Microbiology; pH effects; Pharmaceuticals; Reactors; Reagents; Stability; Stabilization; β-Galactosidase
• ISSN: 0175-7598; 1432-0614
• DOI: 10.1007/s00253-021-11325-8

The food industry has developed a wide range of products with reduced lactose to allow people with intolerance to consume dairy products. Although β-galactosidase has extensive applications in the food, pharma, and biotechnology industries, the enzymes are high-cost catalysts, and their use makes the process costly. Immobilization is a viable strategy for enzyme retention inside a reactor, allowing its reuse and application in continuous processes. Here, we studied the immobilization of β-galactosidase from Bacillus licheniformis in ion exchange resin. A central composite rotational design (CCRD) was proposed to evaluate the immobilization process in relation to three immobilization solution variables: offered enzyme activity, ionic strength, and pH. The conditions that maximized the response were offered enzyme activity of 953 U, 40 mM ionic strength, and pH 4.0. Subsequently, experiments were performed to provide additional stabilization for biocatalyst, using a buffer solution pH 9.0 at 25 °C for 24 h, and crosslinking with different concentrations of glutaraldehyde. The stabilization step drastically impacted the activity of the immobilized enzyme, and the reticulation with different concentrations of glutaraldehyde showed significant influence on the activity of the immobilized enzyme. In spite of substantially affecting the initial activity of the immobilized enzyme, higher reagent concentrations (3.5 g L −1 ) were effective for maintaining stability related to the number of cycles of the enzyme immobilized. The β-galactosidase from Bacillus licheniformis immobilized in Duolite A568 is a promising technique to produce reduced or lactose-free dairy products, as it allows reuse of the biocatalyst, decreasing operational costs. Key Points • Immobilization of β-galactosidase from Bacillus licheniformis in batch reactor • Influence of buffer pH and ionic concentration and offered enzyme activity on immobilization • Influence of glutaraldehyde on operational stability