Pepsin immobilization on biochar by adsorption and covalent binding, and its application for hydrolysis of bovine casein

Shi

J of Chemical Tech & Biotech

2019

BACKGROUND The objective of this research was to use a step‐by‐step method to prepare a novel biocatalytic system (GO‐CEL‐E/N‐GA‐GOD): ‐OH and ‐COOH on the surface of graphene oxide (GO) were used to immobilize cellulase (CEL) and glucose oxidase (GOD), respectively, which may be easier to control the loading of enzymes with different kinds, to achieve the one‐pot conversion of gluconic acid from carboxymethyl cellulose (CMC). RESULTS The loadings capability of CEL and GOD on GO‐CEL‐E/N‐GA‐GOD were 49.07 ± 7.47 mg g−1 and 10.22 ± 2.03 mg g−1, respectively. The multi‐enzyme systems had shallow temperature and pH optima of 40 °C and 5.0. The kinetic constants of GO‐CEL‐E/N‐GA‐GOD (of CEL‐GOD) were Km = 0.15 ± 0.02 (0.43 ± 0.09) mmol L−1, Vmax = 0.18 ± 0.01 (0.21 ± 0.07) μmol L−1 s−1, and kcat/Km = 24.12 ± 0.52 (17.74 ± 0.85) s−1 mmol−1 L. Nearly 65% of the initial activity of GO‐CEL‐E/N‐GA‐GOD could be retained after seven cycles. Notably the conversion of gluconic acid was able to reach 63.82 ± 8.03% within 2 h. CONCLUSION Step‐by‐step immobilization method made full use of different functional groups on GO, avoiding the competition for fixed sites between CEL and GOD in the immobilization processes. The results reflected the feasibility of the strategy to build bio‐microsystem as CEL and GOD immobilized on GO by covalent bonds to achieve the conversion from CMC to gluconic acid in one‐step. © 2019 Society of Chemical Industry

Section: Resultsmentioning

confidence: 96%

Co‐immobilization of cellulase and glucose oxidase on graphene oxide by covalent bonds: a biocatalytic system for one‐pot conversion of gluconic acid from carboxymethyl cellulose

Shi

J of Chemical Tech & Biotech

2019

“…The functionalization of the biochar led to a surface modification of biochar by the insertion of amine-aldehyde groups, which was responsible for the formation of strong interactions between the support material and the pepsin enzyme, thus providing a greater proteolytic activity when compared to immobilization by adsorption. The immobilized enzymes were able to maintain their proteolytic activity for more than seven cycles of reuse [28].…”

Section: Resultsmentioning

confidence: 99%

Immobilization of lipase in biochar obtained from Manihot esculenta Crantz

Oliveira-Ribeiro

Meili

Silva-Belo-Gois

et al. 2019

rev.ion

The immobilized enzymes are catalysts of great industrial interest, as it unites the advantages of heterogeneous catalysis with the high selectivity and mild operation conditions of the enzymes. Biochar is a porous carbonaceous material, which have characteristic that it makes a strong candidate to incorporate enzymes in its structure. Another relevant fact is the possibility of changes and adaptations by synthesis condition in the biochar structure due to the application needs. In this context, the objective of this work was the study of immobilization of lipase (type II, code l3126, Sigma Aldrich) in a biochar produced by pyrolysis (600oC) from an agricultural residue called cassava stump. It was evaluated different enzymatic concentrations (0.1, 0.25 and 0.5 g/L) in order to determine the affinity between the enzyme and biochar. The obtained results showed that the enzyme studied could be easily immobilized in the biochar, obtaining as immobilization yield 61.2% when using the highest concentration of enzyme.

“…It is a reversible method in which enzymes are physically bound to the support material. It involves weak intermolecular interactions, such as Van der Waals forces, electrostatic forces, hydrophobic interactions, and hydrogen bonds [227,228]. With this technique, immobilized enzymes can be easily removed from the support, allowing its reuse in subsequent immobilization cycles [229].…”

Section: Enzyme Immobilizationmentioning

confidence: 99%

Designing of Nanomaterials-Based Enzymatic Biosensors: Synthesis, Properties, and Applications

et al. 2021

Among the many biological entities employed in the development of biosensors, enzymes have attracted the most attention. Nanotechnology has been fostering excellent prospects in the development of enzymatic biosensors, since enzyme immobilization onto conductive nanostructures can improve characteristics that are crucial in biosensor transduction, such as surface-to-volume ratio, signal response, selectivity, sensitivity, conductivity, and biocatalytic activity, among others. These and other advantages of nanomaterial-based enzymatic biosensors are discussed in this work via the compilation of several reports on their applications in different industrial segments. To provide detailed insights into the state of the art of this technology, all the relevant concepts around the topic are discussed, including the properties of enzymes, the mechanisms involved in their immobilization, and the application of different enzyme-derived biosensors and nanomaterials. Finally, there is a discussion around the pressing challenges in this technology, which will be useful for guiding the development of future research in the area.