Mutant 5'UTR Gene for PHA Copolymer Processability

Solution Overview

Problem

Current PHA production methods face challenges due to the brittleness and processing difficulties of poly-3-hydroxybutyrate (P3HB), which limits its applications.

Innovation Solution

A mutant gene encoding phosphoenolpyruvate carboxylase with a mutant 5′-untranslated region (5′UTR) is introduced into a PHA-producing microorganism, allowing for the regulation of 4-hydroxybutyrate (4HB) monomer content in polyhydroxyalkanoate (PHA), thereby improving its physical properties.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If P3HB is synthesized by microorganisms, then biodegradable polymer production is achieved, but brittleness occurs due to high crystallinity and processing becomes difficult

Engineering Contradiction:
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent modifies the 5′UTR sequence of the ppc gene to optimize translation efficiency and control the expression level of phosphoenolpyruvate carboxylase. This parameter change in gene expression leads to altered metabolic flux, resulting in PHA copolymer production with optimized monomer composition that reduces crystallinity and improves processability while maintaining biodegradability

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent produces PHA copolymer consisting of multiple monomers (3HB, 4HB, and other hydroxyalkanoates) instead of pure P3HB. This composite polymer structure with diverse monomer composition reduces crystallinity and brittleness, improving processability while retaining biodegradable properties

Inventive Principle:
Principle #40Composite materials

2Reliability

If P3HB is synthesized to replace petroleum-based plastics, then eco-friendly material production is achieved, but decomposition occurs near melting point making it difficult to process

Engineering Contradiction:
Core Design Contradiction:
ReliabilityVSTemperature

Solution Approach 1:

The patent produces PHA copolymer with multiple monomer types (3HB, 4HB, and other hydroxyalkanoates in varying ratios) instead of pure P3HB. This composite structure lowers the melting point and broadens the processing temperature window, enabling processing below the decomposition temperature while maintaining eco-friendly biodegradable properties

Inventive Principle:
Principle #40Composite materials

3Adaptability or versatility

If 4HB monomer is added to produce P(3HB-co-4HB) copolymer, then elastic properties are improved, but manufacturing complexity increases due to need to control addition ratio

Engineering Contradiction:
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent modifies the 5′UTR sequence of the ppc gene to precisely control the expression level of phosphoenolpyruvate carboxylase. This single parameter change in gene expression automatically regulates the metabolic flux ratio between 3HB and 4HB pathways, producing copolymer with optimized monomer composition without complex manufacturing control systems

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent employs metabolic pathway design where the engineered 5′UTR sequence enables the microorganism to self-regulate the monomer composition ratio. The modified gene expression system automatically balances the production of different hydroxyalkanoate monomers based on available carbon sources, eliminating the need for external control mechanisms

Inventive Principle:
Principle #25Self-service

Data Source

PatentUS20250092429A15'UTR variant sequence of gene encoding phosphoenolpyruvate carboxylase, and uses thereof
Publication Date: 2025.03.20

AI summary

Provided are a mutant gene encoding phosphoenolpyruvate carboxylase including a mutant 5′-untranslated region (5′UTR), a polyhydroxyalkanoate (PHA)-producing microorganism including the gone, and a method of producing PHA using the microorganism.