Optimization of a whole‐cell cadmium sensor with a toggle gene circuit |
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| Authors: | Cindy H. Wu David Le Ashok Mulchandani Wilfred Chen |
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| Affiliation: | 1. Dept. of Chemical and Environmental Engineering, University of California, Riverside, CA 92521;2. Environmental Toxicology Program, University of California, Riverside, CA 92521 |
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| Abstract: | This work demonstrates improvement of a whole‐cell cadmium detection sensor through construction of a gene circuit. A cadmium (II) specific regulatory promoter, PcadR, from Psuedomonas putida 06909, is used in the assembly of a toggle circuit. The circuit contains the cadR promoter fused to lacIq and gfp, and a divergently transcribed tac promoter and cadR. The toggle sensor exhibits lower background fluorescence, and a 20‐fold lower detection limit in comparison to a nontoggle gene circuit. The detection limit of the toggle sensor is 0.01 μM (1.12 ppb) cadmium chloride, and tunable with the addition of isopropyl‐b‐D ‐thiogalactopyranoside (IPTG). The toggle sensor is highly specific to cadmium (II), and no response is elicited from zinc, lead, manganese, nickel, copper, and mercury. © 2009 American Institute of Chemical Engineers Biotechnol. Prog., 2009 |
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| Keywords: | genetic circuits whole‐cell cadmium sensor P. putida 06909 cadR promoter |
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