Microfabricated Microbial Fuel Cell Arrays Reveal Electrochemically Active Microbes
Figure 4
Environmental sample screening with the MFC array.
(A) A schematic representation of the screening process for the environmental microbes with enhanced electricity generation capacities. (B)&(C) Electrochemically active microbes cause discoloration of an azo dye, reactive black 5 in the nutrient agar screening plate. (B) S. oneidensis MR-1 was used as the control; (C) A representative plate with a putative microbe isolate indicated by the red arrow and a non-putative microbe isolate indicated by the white arrow. (D) Phylogenetic tree based on 16S rDNA sequences indicating the relationship of various Shewanella species. (E)–(G) Screening of environmental isolates using the 24-well MFC array. (E) Screening of 13 environmental isolates with S. oneidensis MR-1 as the positive control (SO, red) using two 24-well MFC arrays in parallel. The average power density of two replicates was shown for each isolate. (F) The power density of 7Ca compared to the S. oneidensis MR-1 reference strain (n = 8). (G) Validation of current generation by 7Ca and S. oneidensis MR-1 in conventional MFCs (n = 4).