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Resilience, dynamics, and interactions within a model multispecies exoelectrogenic-biofilm community
Publikationstyp
Journal Article
Date Issued
2017-03-02
Sprache
English
Author(s)
Herausgeber*innen
Volume
83
Issue
6
Article Number
e03033-16
Citation
Applied and Environmental Microbiology 83 (6): e03033-16 (2017)
Publisher DOI
Scopus ID
PubMed ID
28087529
Publisher
Soc.
Anode-associated multispecies exoelectrogenic biofilms are essential for the function of bioelectrochemical systems (BESs). The individual activities of anodeassociated organisms and physiological responses resulting from coculturing are often hard to assess due to the high microbial diversity in these systems. Therefore, we developed a model multispecies biofilm comprising three exoelectrogenic proteobacteria, Shewanella oneidensis, Geobacter sulfurreducens, and Geobacter metallireducens, with the aim to study in detail the biofilm formation dynamics, the interactions between the organisms, and the overall activity of an exoelectrogenic biofilm as a consequence of the applied anode potential. The experiments revealed that the organisms build a stable biofilm on an electrode surface that is rather resilient to changes in the redox potential of the anode. The community operated at maximum electron transfer rates at electrode potentials that were higher than 0.04 V versus a normal hydrogen electrode. Current densities decreased gradually with lower potentials and reached half-maximal values at -0.08 V. Transcriptomic results point toward a positive interaction among the individual strains. S. oneidensis and G. sulfurreducens upregulated their central metabolisms as a response to cultivation under mixed-species conditions. G. sulfurreducens was detected in the planktonic phase of the bioelectrochemical reactors in mixed-culture experiments but not when it was grown in the absence of the other two organisms.
Subjects
Bioelectrochemical systems
Exoelectrogenic biofilm
Geobacter
Shewanella
Transcriptome analysis
DDC Class
570: Biowissenschaften, Biologie