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Synergistic microbial consortium for bioenergy generation from complex natural energy sources.

Wang VB, Yam JK, Chua SL, Zhang Q, Cao B, Chye JL, Yang L - ScientificWorldJournal (2014)

Bottom Line: The monospecies S. oneidensis system was able to generate bioenergy in a short experimental time frame while the monospecies E. coli system generated significantly less bioenergy.The synergistic effect is suggested to arise from E. coli and S. oneidensis utilizing different nutrients as electron donors and effect of flavins secreted by S. oneidensis.Confocal images confirmed the presence of biofilms and point towards their importance in generating bioenergy in MFCs.

View Article: PubMed Central - PubMed

Affiliation: Singapore Centre on Environmental Life Sciences Engineering (SCELSE), Nanyang Technological University, Singapore 637551 ; School of Materials Science and Engineering, Nanyang Technological University, Singapore 639798.

ABSTRACT
Microbial species have evolved diverse mechanisms for utilization of complex carbon sources. Proper combination of targeted species can affect bioenergy production from natural waste products. Here, we established a stable microbial consortium with Escherichia coli and Shewanella oneidensis in microbial fuel cells (MFCs) to produce bioenergy from an abundant natural energy source, in the form of the sarcocarp harvested from coconuts. This component is mostly discarded as waste. However, through its usage as a feedstock for MFCs to produce useful energy in this study, the sarcocarp can be utilized meaningfully. The monospecies S. oneidensis system was able to generate bioenergy in a short experimental time frame while the monospecies E. coli system generated significantly less bioenergy. A combination of E. coli and S. oneidensis in the ratio of 1:9 (v:v) significantly enhanced the experimental time frame and magnitude of bioenergy generation. The synergistic effect is suggested to arise from E. coli and S. oneidensis utilizing different nutrients as electron donors and effect of flavins secreted by S. oneidensis. Confocal images confirmed the presence of biofilms and point towards their importance in generating bioenergy in MFCs.

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Related in: MedlinePlus

Diagram illustrating mechanistic reactions in coculture MFCs. Black schematic depicting nonelectrochemically active microorganisms, such as E. coli; red schematic depicting electrochemically active microorganisms, such as S. oneidensis; blue and green schematics depicting energy sources most favourable for breakdown by electrochemically active and nonelectrochemically active microorganisms, respectively.
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fig3: Diagram illustrating mechanistic reactions in coculture MFCs. Black schematic depicting nonelectrochemically active microorganisms, such as E. coli; red schematic depicting electrochemically active microorganisms, such as S. oneidensis; blue and green schematics depicting energy sources most favourable for breakdown by electrochemically active and nonelectrochemically active microorganisms, respectively.

Mentions: The following possible mechanisms occurring in the coculture system were proposed (Figure 3). Various favourable nutrients (represented by blue and green dots) present in the sarcocarp can be broken down specifically by the independent microbial oxidative actions of non-EAB (E. coli) and EAB (S. oneidensis) in different stages of MFC operation to produce bioenergy. From the electrical data (Figure 2), it is suggested that, for significant and sustained bioenergy production, the EAB should be introduced at a higher concentration. This is to restrict nutrient consumption by non-EAB. The EAB also breaks down its suitable energy source and secretes flavins, which can be utilized by non-EAB at a later stage to facilitate EET. Gradual decline in current densities is due to lack of available nutrients in the closed system (Figure 1).


Synergistic microbial consortium for bioenergy generation from complex natural energy sources.

Wang VB, Yam JK, Chua SL, Zhang Q, Cao B, Chye JL, Yang L - ScientificWorldJournal (2014)

Diagram illustrating mechanistic reactions in coculture MFCs. Black schematic depicting nonelectrochemically active microorganisms, such as E. coli; red schematic depicting electrochemically active microorganisms, such as S. oneidensis; blue and green schematics depicting energy sources most favourable for breakdown by electrochemically active and nonelectrochemically active microorganisms, respectively.
© Copyright Policy - open-access
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4109225&req=5

fig3: Diagram illustrating mechanistic reactions in coculture MFCs. Black schematic depicting nonelectrochemically active microorganisms, such as E. coli; red schematic depicting electrochemically active microorganisms, such as S. oneidensis; blue and green schematics depicting energy sources most favourable for breakdown by electrochemically active and nonelectrochemically active microorganisms, respectively.
Mentions: The following possible mechanisms occurring in the coculture system were proposed (Figure 3). Various favourable nutrients (represented by blue and green dots) present in the sarcocarp can be broken down specifically by the independent microbial oxidative actions of non-EAB (E. coli) and EAB (S. oneidensis) in different stages of MFC operation to produce bioenergy. From the electrical data (Figure 2), it is suggested that, for significant and sustained bioenergy production, the EAB should be introduced at a higher concentration. This is to restrict nutrient consumption by non-EAB. The EAB also breaks down its suitable energy source and secretes flavins, which can be utilized by non-EAB at a later stage to facilitate EET. Gradual decline in current densities is due to lack of available nutrients in the closed system (Figure 1).

Bottom Line: The monospecies S. oneidensis system was able to generate bioenergy in a short experimental time frame while the monospecies E. coli system generated significantly less bioenergy.The synergistic effect is suggested to arise from E. coli and S. oneidensis utilizing different nutrients as electron donors and effect of flavins secreted by S. oneidensis.Confocal images confirmed the presence of biofilms and point towards their importance in generating bioenergy in MFCs.

View Article: PubMed Central - PubMed

Affiliation: Singapore Centre on Environmental Life Sciences Engineering (SCELSE), Nanyang Technological University, Singapore 637551 ; School of Materials Science and Engineering, Nanyang Technological University, Singapore 639798.

ABSTRACT
Microbial species have evolved diverse mechanisms for utilization of complex carbon sources. Proper combination of targeted species can affect bioenergy production from natural waste products. Here, we established a stable microbial consortium with Escherichia coli and Shewanella oneidensis in microbial fuel cells (MFCs) to produce bioenergy from an abundant natural energy source, in the form of the sarcocarp harvested from coconuts. This component is mostly discarded as waste. However, through its usage as a feedstock for MFCs to produce useful energy in this study, the sarcocarp can be utilized meaningfully. The monospecies S. oneidensis system was able to generate bioenergy in a short experimental time frame while the monospecies E. coli system generated significantly less bioenergy. A combination of E. coli and S. oneidensis in the ratio of 1:9 (v:v) significantly enhanced the experimental time frame and magnitude of bioenergy generation. The synergistic effect is suggested to arise from E. coli and S. oneidensis utilizing different nutrients as electron donors and effect of flavins secreted by S. oneidensis. Confocal images confirmed the presence of biofilms and point towards their importance in generating bioenergy in MFCs.

Show MeSH
Related in: MedlinePlus