2 research outputs found
Construction of a Tannase-Immobilized Magnetic Graphene Oxide/Polymer Nanobiocatalyst with Enhanced Enzyme Stability for High-Efficiency Transformation of Tannins
Highly efficient biotransformation of natural compounds
into sustainable
biochemical products has attracted great attention. The integration
of nanoscience and biotechnology provides attractive solutions for
this purpose. Herein, we report the fabrication of a nanobiocatalyst
employing a magnetic graphene oxide/polymer nanocomposite as a robust
carrier for immobilizing the tannase enzyme, which catalyzes the bioconversion
of tannin into gallic acid and glucose. Attributed to the covalent
immobilization and propitious interface properties of the coated polymers
comprising polyethylenimine and sodium hyaluronate, the nanobiocatalyst
is stable without compromising the enzymatic activity. The nanobiocatalyst
exhibits 91.8% activity of original tannase and a high enzyme bound
amount of 356.8 mg g–1. The stability tests at variable
temperatures (30–80 °C) and under pH conditions (4.0–9.0),
various inhibitors, and a long-term storage process (25 days) reveal
that the heterofunctional support and surface microenvironment facilitate
better stability, adaptability, and tolerance ability of the nanobiocatalyst
modified with a multicomponent polymer in comparison to the free enzyme
and the nanobiocatalyst modified with the monocomponent polyethylenimine.
The nanobiocatalyst maintains 94.2% of its initial activity after
10 consecutive uses and is 100% recoverable by applying an external
magnet. Moreover, the nanobiocatalyst is used to hydrolyze 96.5 and
95.1% tannins in extracts from Chinese Torreya grandis testa and cake,
respectively. These results establish the practicability of magnetic
graphene oxide-based supports for immobilizing tannase and the promising
application of immobilized tannase for efficient tannin hydrolysis
Tuning Multiple Counter-Anions in Porous Coordination Polymers with <b>lcy</b> Topology for Acetylene/Ethylene Separation
The efficient separation of acetylene (C2H2) and ethylene (C2H4) is an important
and complex
process in the industry. Herein, we report a new family of lcy-topologic coordination frameworks (termed NTU-90 to NTU-92) with Cu3MF6 (M = Si, Ti, and
Zr) nodes. These charged frameworks are compensated by different counterbalanced
ions (MF62–, BF4–, and Cl–), yielding changes in the size of the
window apertures. Among these frameworks, NTU-92-a (activated NTU-92) shows good adsorption selectivity of C2H2/C2H4 and also significant ability
in recovering both highly pure C2H4 (99.95%)
and C2H2 (99.98%). Our work not only presents
a potential alternative for energy-saving purification of C2 hydrocarbons
but also provides a new approach for tuning the function of charged
porous materials