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Optical Detection of E. coli Bacteria by Mesoporous Silicon Biosensors
Published on: November 20, 2013
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NADPH-related processes studied with a SoxR-based biosensor in Escherichia coli
Alina Spielmann1, Meike Baumgart1, Michael Bott1
1IBG-1: Biotechnology, Institute of Bio- and Geosciences, Forschungszentrum Jülich, Jülich, Germany.
Microbiologyopen
|December 27, 2018
Summary
The pSenSox NADPH biosensor effectively monitors cellular redox states during biotransformation. It revealed how transhydrogenases PntAB and SthA influence nicotinamide adenine dinucleotide phosphate (NADPH) levels in E. coli.
Area of Science:
- Biochemistry
- Molecular Biology
- Metabolic Engineering
Background:
- Nicotinamide adenine dinucleotide phosphate (NADPH) is vital for biosynthesis and oxidative stress defense.
- The genetically encoded NADPH biosensor pSenSox was previously developed using E. coli SoxR and eYFP.
Purpose of the Study:
- To investigate the influence of various parameters on the pSenSox biosensor output in E. coli.
- To study NADPH-related processes during the reductive biotransformation of methyl acetoacetate (MAA) to (R)-methyl 3-hydroxybutyrate (MHB).
Main Methods:
- Utilized the pSenSox NADPH biosensor in E. coli.
- Performed reductive biotransformation using Lactobacillus brevis alcohol dehydrogenase (LbAdh).
- Assessed biosensor response under conditions of varying transhydrogenase (PntAB, SthA) and redox-cycling drug (paraquat, menadione) presence.
Main Results:
- Redox-cycling drugs strongly activated the pSenSox biosensor.
- Absence of RsxABCDGE/RseC enhanced biosensor response, suggesting a SoxR-reducing role.
- Lack of PntAB increased response, while absence of SthA decreased it, indicating opposing roles in NADP+ reduction and NADPH oxidation.
Conclusions:
- The pSenSox biosensor is a valuable tool for studying NADPH-dependent processes in E. coli.
- Transhydrogenases PntAB and SthA play distinct and opposing roles in regulating cellular NADPH levels.
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