1. Highly sensitive microbial biosensor based on recombinant Escherichia coli overexpressing catechol 2,3-dioxygenase for reliable detection of catechol.
- Author
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Liu Z, Zhang Y, Bian C, Xia T, Gao Y, Zhang X, Wang H, Ma H, Hu Y, and Wang X
- Subjects
- Catechol 2,3-Dioxygenase metabolism, Catechols metabolism, Electrodes, Escherichia coli metabolism, Limit of Detection, Recombinant Proteins genetics, Recombinant Proteins metabolism, Sphingomonadaceae metabolism, Up-Regulation, Biosensing Techniques methods, Catechol 2,3-Dioxygenase genetics, Catechols analysis, Escherichia coli genetics, Sphingomonadaceae enzymology, Sphingomonadaceae genetics
- Abstract
A highly sensitive whole cell based electrochemical biosensor was developed for catechol detection in this study. The carE gene of Sphingobium yanoikuyae XLDN2-5 encoding catechol 2,3-dioxygenase (C23O), a key enzyme in the biodegradation of aromatic compound, was cloned and over-expressed in Escherichia coli BL21 (E. coli BL21). Compared to Sphingobium yanoikuyae XLDN2-5, the recombinant E. coli BL21 over-expressed C23O exhibited higher catalytic activity towards catechol. Moreover, the whole cells provided a better environment for C23O to maintain its catalytic activity and stability compared with crude enzyme. The distinctive features of the recombinant E. coli BL21 over-expressed C23O made it an ideal bio-recognition element for the fabrication of a microbial biosensor. Additionally, nanoporous gold (NPG) with unique properties of structure and function was selected as a support to immobilized the recombinant E. coli BL21 over-expressed C23O. Based on the synergistic effect of C23O and NPG, the E. coli BL21-C23O/NPG/GCE bioelectrode showed a good linear response for catechol detection ranging from 1 μM to 500 μM with a high sensitivity of 332.24 μA mM
-1 cm-2 and a low detection limit of 0.24 μM. Besides, the E. coli BL21-C23O/NPG/GCE bioelectrode exhibited strong anti-interference and good stability. For the detection of catechol in wastewater samples, the concentrations detected by the E. coli BL21-C23O/NPG/GCE bioelectrode were in good agreement with the standard concentrations that added in the wastewater samples, which make the E. coli BL21-C23O/NPG/GCE bioelectrode an ideal tool for reliable catechol detection., (Copyright © 2018 Elsevier B.V. All rights reserved.)- Published
- 2019
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