E. coli Strain Metabolic Engineering for Protein and Nucleic Acid Production

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Solution Overview

Problem

E. coli K-12 strains face limitations in growth and protein production due to stalled growth in high-density fermentations, and existing strains either excel in protein production or DNA production but not both, making it challenging to develop standard fermentation regimens for diverse products.

Innovation Solution

Genetically modified E. coli K-12 strains with enhanced orotate phosphoribosyltransferase activity, production of active acetohydroxy acid synthase II, and reduced expression of iclR and arpA gene products, resulting in a reduced genome strain with improved growth and protein/nucleic acid production capabilities.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If E. coli K-12 strains are used for high-density fermentation, then nucleic acid production capability is maintained, but growth stalls and protein production is limited

Engineering Contradiction:
Improvenucleic acid productionVSAvoidgrowth rate
Core Design Contradiction:
Quantity of substanceVSProductivity

Solution Approach 1:

The patent applies parameter changes by modifying specific genetic parameters in the E. coli K-12 strain. The rph gene is deleted to enhance orotate phosphoribosyltransferase activity, the ilvG gene is corrected to produce active acetohydroxy acid synthase II, and the iclR and arpA genes are deleted to reduce expression of their gene products. These genetic parameter changes resolve the contradiction by improving metabolic capacity and growth rate while maintaining nucleic acid production capability.

Inventive Principle:
Principle #35Parameter changes

2Productivity

If E. coli B strains are used for protein production, then protein production characteristics are superior, but mobile genetic elements cause production problems under stress

Engineering Contradiction:
Improveprotein productionVSAvoidproduction stability
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent applies the taking out principle by selectively removing problematic mobile genetic elements from the E. coli genome. Specifically, insertion sequence elements and prophage are removed to eliminate sources of production instability under stress conditions, while retaining the superior protein production characteristics of B strains through metabolic pathway optimizations.

Inventive Principle:
Principle #2Taking out (Extraction)

3Adaptability or versatility

If a single strain platform is developed for both protein and DNA production, then versatility is improved, but strain complexity increases

Engineering Contradiction:
Improvemulti-purpose capabilityVSAvoidstrain genetic complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent applies universality by creating a single E. coli K-12 strain platform that can perform both protein production and nucleic acid production functions. Through targeted genetic modifications including deletion of rph, correction of ilvG, and deletion of iclR and arpA, the strain achieves enhanced metabolic capacity that supports both production modes without requiring multiple specialized strains.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Data Source

PatentEP3068887B1Bacteria with improved metabolic capacity
Publication Date: 2019.10.30 SCARAB GENOMICS LLC
  • EP3068887B1 patent drawingFigure 1
  • EP3068887B1 patent drawingFigure 2
  • EP3068887B1 patent drawingFigure 3

AI summary

E. coli bacteria comprising genetic modifications to enhance fermentability and production of protein and nucleic acids are provided.