Device

Part:BBa_K1172504

Designed by: Lukas Rositzka   Group: iGEM13_Bielefeld-Germany   (2013-08-28)

Outer membrane porin OprF from Pseudomonas fluorescens with medium Anderson promotor and weak RBS

Usage and Biology

The Microbial Fuel Cell (MFC) can be a future environmentally friendly biotechnological application for the production of electrical energy. As a future alternative energy source, the bioelectricity generation must become more efficient. A major limiting factor is the low bacterial membrane permeability, hindering transport of electron shuttles through the membrane and thereby restricting the electron shuttle-mediated extracellular electron transfer (EET) from bacteria to electrodes. This results in a reduced electrical power output of the MFC. Therefore, we heterologously expressed the porin protein OprF from Pseudomonas fluorescens into Escherichia coli.

Figure 1: Schematic overview of the enhancement mechanism of electron shuttle-mediated electron transfer between bacteria and the anode of MFCs by the synthetic porin OprF. Oxidized mediators diffuse into the periplasmatic space where they accept electrons. Reduced mediators are secreted through outer membrane porins and donate their electrons to the electrode.

Heterologous expression of the porin protein OprF from Pseudomonas fluorescens into Escherichia coli leads to a much higher current output in comparison to its parental strain (E. coli KRX). This is most likely caused by improved electron shuttle-mediated extracellular electron transfer through dramatically increased membrane permeability. The heterologous expression of the outer membrane porin OprF from Pseudomonas fluorescens in Escherichia coli is a great genetic strategy to overcome limitations due to the membrane and to increase electricity generation by microorganisms.


Important parameters

The oprF gene from Pseudomonas fluorescens was cloned and heterologously expressed in Escherichia coli KRX under the control of medium Anderson promoter and weak RBS. Besides several other promoters (Table 1) were combined with the coding part oprF in order to characterize the expression of the outer membrane porin OprF.

Table 1: Overview of oprF devices. Combination of oprF coding BioBrick (BBa_K1172501) with different promoters and RBS. The characterization of this BioBrick was performed by comparing Escherichia coli KRX wild type with Escherichia coli KRX carrying BBa_K1172502, BBa_K1172503, BBa_K1172504, BBa_K1172505 and BBa_K1172507.


Sequence and Features


Assembly Compatibility:
  • 10
    COMPATIBLE WITH RFC[10]
  • 12
    INCOMPATIBLE WITH RFC[12]
    Illegal NheI site found at 7
    Illegal NheI site found at 30
  • 21
    INCOMPATIBLE WITH RFC[21]
    Illegal BglII site found at 827
  • 23
    COMPATIBLE WITH RFC[23]
  • 25
    INCOMPATIBLE WITH RFC[25]
    Illegal NgoMIV site found at 1219
  • 1000
    INCOMPATIBLE WITH RFC[1000]
    Illegal BsaI site found at 740

Results

This part was used to characterize the outer membrane porin OprF (BBa_K1172501). Please look at the Parts Registry page for BBa_K1172501 for results and detailed information.


[edit]
Categories
//cds/membrane
Parameters
None