PilA mutant

Low Conductance in Fumarate-Grown Biofilms When the gold electrodes were not connected to the cathode, but fiimarate was provided in solution as an alternative electron acceptor, biofilms of wild-type and PilA mutant DL-1 strain were formed on the gold surfaces and bridged the nonconductive gap. However, these biofilms exhibited very low conductivity (Fig. 7.9). These results demonstrated that the conductivity of the biofilm depends on the physiological status of the cells. 

S.2 Current-Producing PilA Mutant Biofilms Biofilms of PilA mutant of DL-1 strain of G. sulfurreducens and PilA mutant strain of Geobacter sirdin Speedy produced 10 times less current and did not bridge the nonconducting gap. This is consistent with previous studies that have demonstrated that because pili are electrically conductive [60], they are required for the development of the thick anode biofilms necessary for high-density current production by G. sulfurreducens [35,61]. 

Fig. 3 Optical and electronic photographs of a PILA-overproducer mutant of Pseudomonas putida U cultured in a chemically defined medium containing 8-phenyloctanoic acid (10 mM) as a poly(3-hydroxyphenylalkanoate) precursor, and L-glutamate (10 mM) as the carbon source...

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