Mutant 5'UTR Sequence Regulates PHA Crystallinity and Processability

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Solution Overview

Problem

Existing polyhydroxyalkanoate (PHA)-producing microorganisms, thereby providing PHA having desired physical properties, and maintaining the appropriate content of 4-hydroxybutyrate (4HB) monomer in polyhydroxyalkanoate (PHA) to achieve desired physical properties.

Innovation Solution

A mutant 5'-untranslated region (5'UTR) sequence is introduced in the gene encoding phosphoenolpyruvate carboxylase, specifically mutating bases at positions 3, 4, 5, 7, 8, and 10 in the nucleotide sequence, to control carbon flux and 4-hydroxybutyrate content in PHA-producing microorganisms.

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 difficulty arises because it decomposes near its melting point

Engineering Contradiction:

ImprovebiodegradabilityVSAvoidprocessability

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The patent modifies the 5'UTR sequence parameters of the ppc gene to alter expression levels of phosphoenolpyruvate carboxylase, thereby changing the carbon flux distribution in the TCA cycle. This leads to altered 4HB monomer content in PHA, which in turn changes the crystallinity and melting properties of the polymer, improving processability while maintaining biodegradability

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent produces PHA copolymers containing both 3HB and 4HB monomers. The 4HB component acts as a modifier that reduces crystallinity and lowers the melting point, creating a composite polymer structure that combines the biodegradability of P3HB with improved processability characteristics

Inventive Principle:

Principle #40Composite materials

2Ease of manufacture

If 4HB monomer is added to produce P(3HB-co-4HB) copolymer, then processability is improved, but control over 4HB content becomes critical to achieve desired physical properties

Engineering Contradiction:

ImproveprocessabilityVSAvoid4HB content control

Core Design Contradiction:

Ease of manufactureVSManufacturing precision

Solution Approach 1:

The patent employs a specific 5'UTR mutant sequence that provides precise regulatory control over ppc gene expression. This regulatory mechanism acts as a feedback system that maintains stable 4HB content in the PHA copolymer, ensuring consistent physical properties and processability across production batches

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

By specifically mutating bases at positions 3, 4, 5, 7, 8, and 10 in the 5'UTR sequence, the patent precisely adjusts the expression level of phosphoenolpyruvate carboxylase. This precise parameter change in the regulatory region translates to controlled 4HB monomer incorporation, achieving the desired manufacturing precision

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentEP4663756A15'UTR variant sequence of gene encoding phosphoenolpyruvate carboxylase, and uses thereof

Publication Date: 2025.12.17 CJ CHEILJEDANG CORP

AI summary

The present application relates to: a variant gene encoding phosphoenolpyruvate carboxylase, which comprises a variant 5'-untranslated region (5'UTR), the variant gene comprising a ribosome-binding site (RBS) variant sequence; a polyhydroxyalkanoate (PHA)-producing microorganism comprising the gene; and a PHA production method using same.