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Electrochemical H₂O₂ - stat mode as reaction concept to improve the process performance of an unspecific peroxygenase
Citation Link: https://doi.org/10.15480/882.8794
Publikationstyp
Journal Article
Date Issued
2023-12-25
Sprache
English
Author(s)
TORE-DOI
Journal
Volume
78
Start Page
95
End Page
104
Citation
New Biotechnology 78: 95-104 (2023-12-25)
Publisher DOI
Scopus ID
Publisher
Elsevier B.V.
The electroenzymatic hydroxylation of 4-ethylbenzoic acid catalyzed by the recombinant unspecific peroxygenase from the fungus Agrocybe aegerita (rAaeUPO) was performed in a gas diffusion electrode (GDE)-based system. Enzyme stability and productivity are significantly affected by the way the co-substrate hydrogen peroxide (H2O2) is supplied. In this study, two in-situ electrogeneration modes of H2O2 were established and compared. Experiments under galvanostatic conditions (constant productivity of H2O2) were conducted at current densities spanning from 0.8 mA cm−2 to 6.4 mA cm−2. For comparison, experiments under H2O2-stat mode (constant H2O2 concentration) were performed. Here, four H2O2 concentrations between 0.06 mM and 0.28 mM were tested. A maximum H2O2 productivity of 5.5 µM min−1 cm−2 and productivity of 10.5 g L−1 d−1 were achieved under the galvanostatic condition at 6.4 mA cm−2. Meanwhile, the highest total turnover number (TTN) of 710,000 mol mol−1 and turnover frequency (TOF) of 87.5 s−1 were obtained under the H2O2-stat mode at concentration limits of 0.15 mM and 0.28 mM, respectively. The most favorable outcome in terms of maximum achievable TTN, TOF and productivity was found under the H2O2-stat mode at concentration limit of 0.2 mM. Here, a TTN of 655,000 mol mol−1, a TOF of 80.3 s−1 and a productivity of 6.1 g L−1 d−1 were achieved. The electrochemical H2O2-stat mode not only offers a promising alternative reaction concept to the well-established galvanostatic mode but also enhances the process performance of unspecific peroxygenases.
Subjects
Biocatalysis
Bioelectrocatalysis
Bioelectrochemical system
Electrosynthesis
Hydrogen peroxide
DDC Class
660: Chemistry; Chemical Engineering
Publication version
publishedVersion
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1-s2.0-S1871678423000596-main.pdf
Type
Main Article
Size
4.68 MB
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