Geobacter Strains Using Pyruvate as Electron Donor
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Solution Overview
Problem
Geobacter species have a limited range of organic compounds that can be used as electron donors for power production, primarily limited to simple molecules such as acetate and hydrogen, which restricts the applications in bioremediation and microbial fuel cells.
Innovation Solution
Development of new Geobacter strains with mutations in genes encoding repressors of succinyl-CoA synthetase, allowing them to efficiently utilize C3 to C12 organic compounds like pyruvate and its metabolic precursors as electron donors, expanding their metabolic capabilities.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If Geobacter species use only simple organic compounds like acetate and hydrogen as electron donors, then the metabolic pathway is simple and well-characterized, but the range of applicable organic compounds for power production is limited
Solution Approach 1:
The patent applies parameter changes by mutating specific genes (such as those encoding repressors of succinyl-CoA synthetase) to alter the metabolic parameters of Geobacter species. This enables the bacteria to utilize a broader range of organic compounds (C3 to C12 compounds including pyruvate, lactate, propionate, butyrate, and their precursors) as electron donors, transforming the metabolic capability from using only simple compounds like acetate to utilizing complex organic compounds while maintaining controlled metabolic pathway integration
2Adaptability or versatility
If Geobacter species are engineered to use C3 to C12 organic compounds as electron donors, then the versatility for bioremediation and fuel cell applications is improved, but the metabolic pathway complexity increases
Solution Approach 1:
The patent employs parameter changes through targeted gene mutations, specifically in repressor genes of succinyl-CoA synthetase, to enable Geobacter species to metabolize C3 to C12 organic compounds. This genetic parameter modification allows the bacteria to expand their substrate utilization range without requiring complete reconstruction of their metabolic pathways, thereby improving versatility while controlling the degree of complexity increase
Solution Approach 2:
The engineered Geobacter species achieve multi-functionality by gaining the ability to utilize multiple types of organic compounds (pyruvate, lactate, propionate, butyrate, and their metabolic precursors) as electron donors. This universal capability allows the same bacterial strain to be applied in diverse scenarios including bioremediation of various contaminants and power generation from different organic waste streams, improving adaptability across multiple applications
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
These strains demonstrate improved growth rates and energy production using a broader range of organic compounds, enhancing bioremediation and microbial fuel cell applications, including power generation from complex wastes and improved bioremediation of contaminants.
Implementation Method 1
Geobacter sulfurreducens has the ability to oxidize acetate completely to CO2
Implementation Method 2
Geobacter species are highly important in bioremediation applications. For example, their ability to reduce toxic metals such as soluble uranium (VI) to insoluble uranium (IV)
Implementation Method 3
Extracellular electron transport to soluble and insoluble electron acceptors is made possible by periplasmic and outer membrane c-type cytochromes as well as conductive pilli termed nanowires
Implementation Method 4
Another application for bioremediation is that G. sulfurreducens' ability to reduce compounds (e.g., Fe(III)) can be coupled with the oxidation of organic contaminates such as petroleum and landfill leachate
Data Source
AI summary
In preferred embodiments, the present invention provides new isolated strains of a Geobacter species that are capable of using a carbon source that is selected from C3 to C12 organic compounds selected from pyruvate or metabolic precursors of pyruvate as an electron donor in metabolism and in subsequent energy production. The wild type strain of the microorganisms has been shown to be unable to use these C3 to C12 organic compounds as electron donors. The inventive strains of microorganisms are useful for improving bioremediation applications, including in situ bioremediation (including uranium bioremediation and halogenated solvent bioremediation), microbial fuel cells, power generation from small and large-scale waste facilities (e.g., biomass waste from dairy, agriculture, food processing, brewery, or vintner industries, etc.) using microbial fuel cells, and other applications of microbial fuel cells, including, but not limited to, improved electrical power supplies for environmental sensors, electronic devices, and electric vehicles.