Simultaneous cellulose degradation and electricity production by Enterobacter cloacae in a microbial fuel cell.
Electricity can be directly generated by bacteria in microbial fuel cells (MFCs) from many different biodegradable substrates. When cellulose is used as the substrate, electricity generation requires a microbial community with both cellulolytic and exoelectrogenic activities. Cellulose degradation with electricity production by a pure culture has not been previously demonstrated without addition of an exogenous mediator. Using a specially designed U-tube MFC, we enriched a consortium of exoelectrogenic bacteria capable of using cellulose as the sole electron donor. After 19 dilution-to-extinction serial transfers of the consortium, 16S rRNA gene-based community analysis using denaturing gradient gel electrophoresis and band sequencing revealed that the dominant bacterium was Enterobacter cloacae. An isolate designated E. cloacae FR from the enrichment was found to be 100% identical to E. cloacae ATCC 13047(T) based on a partial 16S rRNA sequence. In polarization tests using the U-tube MFC and cellulose as a substrate, strain FR produced 4.9 +/- 0.01 mW/m(2), compared to 5.4 +/- 0.3 mW/m(2) for strain ATCC 13047(T). These results demonstrate for the first time that it is possible to generate electricity from cellulose using a single bacterial strain without exogenous mediators.
Rezaei
Farzaneh
F
Department of Agricultural and Biological Engineering, The Pennsylvania State University, University Park, 16802, USA.
Xing
Defeng
D
Wagner
Rachel
R
Regan
John M
JM
Richard
Tom L
TL
Logan
Bruce E
BE
D001674:Bioelectric Energy Sources / Q000382:microbiology*; D002482:Cellulose / Q000378:metabolism*; D016000:Cluster Analysis; D016172:DNA Fingerprinting; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D004560:Electricity; D004591:Electrophoresis, Polyacrylamide Gel; D016972:Enterobacter cloacae / Q000145:classification* / Q000302:isolation & purification* / Q000378:metabolism; D008969:Molecular Sequence Data; D009691:Nucleic Acid Denaturation; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D017422:Sequence Analysis, DNA; D012689:Sequence Homology, Nucleic Acid
D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D012336:RNA, Ribosomal, 16S; D002482:Cellulose