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Proof of principle for an engineered microbial biosensor based on Shewanella oneidensis outer membrane protein complexes
Publikationstyp
Journal Article
Date Issued
2013-03-22
Sprache
English
Author(s)
Journal
Volume
47
Start Page
285
End Page
291
Citation
Biosensors and Bioelectronics 47: 285-291 (2013-09-05)
Publisher DOI
Scopus ID
PubMed ID
23584391
Publisher
Elsevier Science
Shewanella oneidensis is known for its ability to respire on extracellular electron acceptors. The spectrum of these acceptors also includes anode surfaces. Based on this activity, a versatile S. oneidensis based biosensor strain was constructed in which electricity production can be modulated. Construction started with the identification of a usable rate-limiting step of electron transfer to an anode. Thereafter, the sensor strain was genetically engineered to produce a protein complex consisting of the three proteins MtrA, MtrB and MtrF. This complex is associated to the outer membrane and most probably enables membrane spanning electron transfer. MtrF is an outer membrane cytochrome that catalyzes electron transfer reactions on the cell surface. Under anoxic conditions, wild type cells do not express MtrF but rather MtrC as electron transferring outer membrane cytochrome. Still, our analysis revealed that MtrF compared to MtrC overexpression is less toxic to the cell which gives MtrF a superior position for biosensor based applications. Transcription of mtrA, mtrB and mtrF was linked up to an inducible promoter system, which positively reacts to rising l-arabinose concentrations. Anode reduction mediated by this strain was linearly dependent on the arabinose content of the medium. This linear dependency was detectable over a wide range of arabinose concentrations. The l-arabinose biosensor presented in this study proves the principle of an outer membrane complex based sensing method which could be easily modified to different specificities by a simple change of the regulatory elements.
Subjects
MtrA
MtrB
MtrF
Outer membrane cytochromes
Shewanella oneidensis
Specific microbial biosensor
DDC Class
570: Biowissenschaften, Biologie
600: Technik