Robust glucose oxidase with a Fe₃O₄@C-silica nanohybrid structure

Abstract

Biomolecules, especially enzymes, usually have poor thermal and operational stability as well as limited reuse cycles, which greatly limit their industrial practices. Inspired by the biomineralization strategy evolved by natural organisms, we suggest nanohybrid enzyme formulation by in situ encapsulating enzyme loaded functional Fe 3 O 4 @C nanoparticles with silica. By using glucose oxidase (GOD) as an example, we demonstrate that the obtained enzyme-material hybrids are featured by their significantly enhanced operational and thermal stabilities, which exhibit a relatively steady catalytic ability in a board range of 25 1C to 65 1C. Even after 4 h of incubation at 55 1C, the GOD-material composites still retain 77% of their initial activity while the native ones only retain 30%. Besides, the nanohybrids show excellent reusability because the magnetic character of the integrated Fe 3 O 4 particles facilitates the enzyme separation and recycle. This attempt provides a valuable approach for biological improvement by using functional materials.

Feasibility study for slope soil stabilization by microbial induced carbonate precipitation (MICP) using indigenous bacteria isolated from cold subarctic region

“…The selection of suitable ureolytic bacteria is highly important in urease-based MICP technique. The enzymes of the bacteria are thermal sensitive and can readily be denatured by even a slight change of environmental temperature [22]. Most of the MICP studies have employed Sporosarcina pasteurrii for urea hydrolysis due to the highly active urease enzyme [5,6,11,13,[23][24][25].…”

Affinity Immobilization of a Bacterial Prolidase onto Metal-Ion-Chelated Magnetic Nanoparticles for the Hydrolysis of Organophosphorus Compounds

“…Storage stability is an important advantage of immobilized enzymes over their free counterparts since some previous investigations have already reported that free biocatalysts can usually lose their activities fairly quickly during storage [52,53,54,55]. In our case, the storage stability of free and immobilized His 6 - Ec PepQ was compared and the relevant research results are shown in Figure 6A.…”

“…Based on the established FTIR spectra of iron oxides [51], the low-intensity band at approximately 3460 cm −1 can be assigned to OH stretching due to the presence of water traces. Interestingly, the 3460 cm −1 signal can also be seen in the FTIR spectra of iron oxides synthesized by different research teams [8,9,40,42,52,53]. However, the exact reason for the presence of water traces in the prepared iron oxides remains unclear.…”

“…In comparison with free enzyme, His 6 - Ec PepQ@NiNTAMPNs displayed a higher activity against Ala-Pro at 70 °C and pH ranges of 5.5 to 10. The SiMNP-immobilized form of a variety of enzymes has been consistently found to be active over a wide range of temperature and pH [6,7,53].…”

Fast swelling behaviors of thermosensitive poly(N‐isopropylacrylamide‐co‐methacryloxyethyltrimethyl ammonium chloride)/Na2WO4 cationic composite hydrogels

“…The EDS test of N 5 D 1 W 17 hydrogel further confirmed that W element was present in the hydrogel [ Figure 2 groups, such as ammonium groups and ester groups. 38 The maximum degradation temperature (T max ) for the hydrogel sample was found at 344.8 8C with a weight loss of 47.86 wt % at third degradation stage, which could be attributed to the weight loss of functional groups and the polymer main-chain scission and the destruction of crosslinked network structure. In the fourth stage, the further decomposition of the organic matter in the hydrogel taken place in 454-540 8C.…”