title: Relationship between sol-gel conditions and enzyme stability: a case study with β-galactosidase/silica biocatalyst for whey hydrolysis.
abstract: The sol-gel process has been very useful for preparing active and stable biocatalysts, with the possibility of being reused. Especially those based on silica are well known. However, the study of the enzyme behavior during this process is not well understood until now and more, if the surfactant is involved in the synthesis mixture. This work is devoted to the encapsulation of β-galactosidase from Bacillus circulans in silica by sol-gel process, assisted by non-ionic Triton X-100 surfactant. The correlation between enzyme activity results for the β-galactosidase in three different environments (soluble in buffered aqueous reference solution, in the silica sol, and entrapment on the silica matrix) explains the enzyme behavior under stress conditions offered by the silica sol composition and gelation conditions. A stable β-galactosidase/silica biocatalyst is obtained using sodium silicate, which is a cheap source of silica, in the presence of non-ionic Triton X-100, which avoids the enzyme deactivation, even at 40 °C. The obtained biocatalyst is used in the whey hydrolysis for obtaining high value products from this waste. The preservation of the enzyme stability, which is one of the most important challenges on the enzyme immobilization through the silica sol-gel, is achieved in this study.
authors: a Grupo Ciencia de los Materiales, Instituto de Química, Facultad de Ciencias Exactas y Naturales , Universidad de Antioquia UdeA , Calle 70 No. 52-21, Medellín , Colombia.
authors: Sindy
authors: S
authors: Escobar
authors: b Escuela de Ingeniería Bioquímica, Pontificia Universidad Católica de Valparaíso , P.O. Box 4059, Valparaíso , Chile.
authors: Claudia
authors: C
authors: Bernal
authors: a Grupo Ciencia de los Materiales, Instituto de Química, Facultad de Ciencias Exactas y Naturales , Universidad de Antioquia UdeA , Calle 70 No. 52-21, Medellín , Colombia.
authors: Monica
authors: M
authors: Mesa
mesh_terms: D001407:Bacillus / Q000201:enzymology; D001426:Bacterial Proteins / Q000737:chemistry / Q000378:metabolism*; D004795:Enzyme Stability; D004800:Enzymes, Immobilized / Q000737:chemistry / Q000378:metabolism*; D005525:Food-Processing Industry / Q000191:economics; D005947:Glucose / Q000191:economics / Q000302:isolation & purification / Q000378:metabolism*; D006868:Hydrolysis; D007220:Industrial Waste / Q000032:analysis / Q000191:economics; D007700:Kinetics; D007785:Lactose / Q000378:metabolism; D064427:Nutritive Sweeteners / Q000191:economics / Q000302:isolation & purification / Q000378:metabolism*; D017830:Octoxynol / Q000737:chemistry; D044367:Phase Transition; D058428:Silica Gel / Q000737:chemistry*; D013020:South America; D013501:Surface-Active Agents / Q000737:chemistry; D044366:Transition Temperature; D000067796:Whey / Q000191:economics / Q000378:metabolism*; D001616:beta-Galactosidase / Q000737:chemistry / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D004800:Enzymes, Immobilized; D007220:Industrial Waste; D064427:Nutritive Sweeteners; D013501:Surface-Active Agents; D058428:Silica Gel; D017830:Octoxynol; D001616:beta-Galactosidase; D005947:Glucose; D007785:Lactose
keywords: Triton X-100 surfactant; enzymatic stability; silica sol–gel encapsulation; β-galactosidase