Electrical wiring of live, metabolically enhanced Bacillus subtilis cells with flexible osmium-redox polymers.
The present study explores genetic engineering of the respiratory chain and the application of two different flexible osmium redox polymers to achieve efficient electric communication between the gram-positive organism Bacillus subtilis and an electrode. Poly(1-vinylimidazole)(12)-[Os-(4,4'-dimethyl-2,2'-bipyridyl)(2)Cl(2)](+/2+) (osmium redox polymer I) and poly(vinylpyridine)-[Os-(N,N'-methylated-2,2'-biimidazole)(3)](2+/3+) (osmium redox polymer II) were investigated for efficient electrical "wiring" of viable gram-positive bacterial cells to electrodes. Using a B. subtilis strain that overproduces succinate/quinone oxidoreductase (respiratory complex II), we were able to improve the current response several fold using succinate as substrate, in both batch and flow analysis modes, and using gold and graphite electrodes. The efficiency of the osmium redox polymer, working as electron transfer mediator between the cells and the electrode, was compared with that of a soluble mediator (hexacyanoferrate). The results demonstrated that mediators did not have to pass the cytosolic membrane to bring about an efficient electronic communication between bacterial cells with a thick cell wall and electrodes.
Coman
Vasile
V
Department of Biochemistry, Lund University, P.O. Box 124, SE-221 00 Lund, Sweden.
Gustavsson
Tobias
T
Finkelsteinas
Arnonas
A
von Wachenfeldt
Claes
C
Hägerhäll
Cecilia
C
Gorton
Lo
L
D001412:Bacillus subtilis / Q000166:cytology* / Q000378:metabolism; D055664:Electrochemical Techniques; D004566:Electrodes; D042963:Electron Transport Complex II / Q000235:genetics; D005818:Genetic Engineering; D009992:Osmium; D011108:Polymers
D011108:Polymers; C478189:respiratory complex II; D009992:Osmium; D042963:Electron Transport Complex II