Acetyl-CoA Production via CO2 Fixation in Pantoea
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for producing acetyl-CoA-derived chemicals, such as glutamic acid, through carbon dioxide fixation in microorganisms are inefficient due to enzyme activity limitations and the presence of enzymes that consume acetyl-CoA, leading to suboptimal yields and increased waste production.
Innovation Solution
Introducing malate thiokinase and malyl-CoA lyase enzymatic activities into Pantoea bacteria to create a carbon dioxide fixation pathway that converts CO2 to acetyl-CoA without consuming acetyl-CoA, thereby enhancing the conversion efficiency and reducing waste products.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional carbon dioxide fixation pathways are introduced into microorganisms to produce acetyl-CoA-derived chemicals, then carbon source utilization is improved, but enzyme activity limitations and acetyl-CoA consumption reduce production yield
Solution Approach 1:
The patent removes enzymes that consume acetyl-CoA from the metabolic pathway by genetic manipulation. Specifically, it inactivates or deletes genes encoding enzymes such as acetyl-CoA carboxylase and other acetyl-CoA-consuming enzymes, thereby preventing the loss of acetyl-CoA to side reactions and directing carbon flow toward the desired product synthesis pathway.
Solution Approach 2:
The patent optimizes enzyme parameters by introducing engineered carbon dioxide fixation pathways with enhanced enzyme activities. It modifies key enzymatic parameters including increasing the activity of carbon dioxide fixation enzymes and adjusting metabolic flux distribution to maximize acetyl-CoA production while minimizing consumption, thereby improving overall pathway efficiency and product yield.
2Productivity
If multiple enzymes are introduced to create complete carbon dioxide fixation pathways, then conversion efficiency is improved, but pathway complexity increases and waste production increases
Solution Approach 1:
The patent extracts and removes unnecessary or harmful enzymes from the metabolic pathway through genetic manipulation. It specifically eliminates enzymes that create competing pathways or consume acetyl-CoA, thereby simplifying the overall metabolic network while maintaining high conversion efficiency of carbon dioxide to acetyl-CoA.
Solution Approach 2:
The patent employs enzymes that perform multiple functions within the metabolic pathway. Selected enzymes are capable of catalyzing multiple reactions or serving both anabolic and catabolic functions, thereby reducing the total number of enzymes required while maintaining pathway efficiency and reducing complexity.
3Quantity of substance
If conventional pathways are used for acetyl-CoA production, then carbon source metabolism is maintained, but carbon loss as CO2 and formate reduces chemical yield
Solution Approach 1:
The patent converts the harmful by-products (CO2 and formate) back into useful acetyl-CoA through engineered reverse pathways. It introduces carbon dioxide fixation enzymes that catalyze the conversion of CO2 and formate back into acetyl-CoA, thereby transforming waste products into valuable intermediates and increasing overall carbon utilization efficiency and chemical yield.
Solution Approach 2:
The patent recovers carbon that would otherwise be discarded as CO2 and formate by introducing carbon dioxide fixation pathways. The system captures and reutilizes these carbon-containing by-products, converting them back into acetyl-CoA and other useful metabolites, thereby reducing carbon loss and improving the overall yield of desired chemicals.
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
This approach results in higher yields of acetyl-CoA-derived chemicals like glutamic acid with reduced biomass and waste, improving the economic viability and efficiency of the fermentation process.
Implementation Method 1
Introducing malate thiokinase and malyl-CoA lyase enzymatic activities into Pantoea bacteria to create a carbon dioxide fixation pathway that converts CO2 to acetyl-CoA
Implementation Method 2
create a carbon dioxide fixation pathway that converts CO2 to acetyl-CoA without consuming acetyl-CoA, thereby enhancing the conversion efficiency
Data Source
AI summary
Disclosed is an acetyl-CoA-producing microorganism, which is obtained by imparting malate thiokinase and malyl-CoA lyase enzymatic activities to a microorganism having none of the following (a), (b), (c) or (d), without imparting any of (a), (b), (c) or (d), or, even when one or more of (a), (b), (c) or (d) are imparted, not allowing the functions thereof to be exerted: (a) a carbon dioxide fixation cycle having an enzymatic reaction from malonyl-CoA to malonate semialdehyde or 3-hydroxypropionate, (b) a carbon dioxide fixation cycle having an enzymatic reaction from acetyl-CoA and CO2 to pyruvate, (c) a carbon dioxide fixation cycle having an enzymatic reaction from crotonyl-CoA and CO2 to ethylmalonyl-CoA or glutaconyl-CoA or (d) a carbon dioxide fixation cycle having an enzymatic reaction from CO2 to formate.