Biology Reference
In-Depth Information
universal design of the array makes it possible to easily change the anode and cathode
to quickly explore new electrode materials to further optimize the MFC architecture.
Fourth, the device can support factorial experiments in which several variables are
tested and compared simultaneously. This feature will dramatically accelerate the pace
of electricigen research. Fifth, the highly scalable approaches used to microfabricate
the array set the stage for the development of next-generation parallel devices with
more than 1,000 wells. Finally, the array provides a platform for MFC performance to
be assessed in parallel (increasing MFC experimental throughput by 24-fold). We ex-
ploited this feature to identify and characterize electricigens with high electrochemical
activities. In this regard, the fact that several microbes with enhanced electrochemical
activity were rapidly uncovered in our screen indicates that the natural environment
constitutes a plentiful reservoir for mining electricigens. For example, our screen un-
covered four
Pseudomonas
sp. (Table 1) that produce phenazine-based metabolites
that can serve as electron shuttles [40, 41]. Moreover, the screen resolved
Bacillus
sp.
and
Aeromonas hydrophila
that have been reported to be present in microbial consor-
tia of MFCs [26]. A
Shewanella
isolate 7Ca, which generated power density that was
2.3-fold above the reference strain, was also uncovered (Figure 4E).
Table 1.
Identities of environmental isolates obtained from pre-screening.
Isolate
Top Hit (Genbank Number)
Identity%
lB
Bacillus sp. RC33 (F J263036.1)
100
lC
Bacillus sp. Wl-17 (FJ560473.1)
100
1D
Bacillus niacini strain YM 1 C7 (EU221338. 1)
97.93
2A#
Enterobacter sp. CTSP29 (EU855207 .1)
99
2B
Bacillus sp. SXSl (00227355.1)
2C, 3B, 4A, 5A,5B
Bacillus thuringiensis serovar tenebrionis (EU429671.1)
100
3A
Bacterium 3A13 (00298760.1)
99
3C
Arthrobacter sp. FB24 (EU147009.1)
100
3E, 3F
Bacillus sp. A 1 (2008) (F J535468. 1)
100
5C
Bacillus sp. BMl-4 (FJ528077.1)
100
6A,6C*
Pseudomonas putida strain J3 1 2 (EF2032 1 0.1)
98.50
6B*· #
Stenotrophomonas maftophilia strain CMG3098 (EU048328.1)
98.99
6E*
Pseudomonas pfecogfossicida strain 519 (00095907.1)
98.52
6F*
Pseudomonas sp. lm 1 0 (EU240462. 1)
98.72
6G*
Pseudomonas sp. GNE25 (AM397659. 1)
95
7A*· #
Aeromonas sp. LOl 51 (AM913921.1)
97.34
7Ca*
Shewanella sp. Hac353 (00307734. 1)
99
7Cb
Bacillus pumifus strain TPRl 8 (EU373436. 1)
99
8A*· #
Paenibacillus sp. oral clone CA007 (AF385540. 1)
92
8B*·#
Aeromonas hydrophi/a strain IB343 (EU770277.1)
99
*isolates belonging to y-proteobacteria (1 0 out of 26 isolates).
#putative pathogenic isolates not subject to electricity generation screening using MFC array.
