(R)-3-Hydroxybutyric Acid Fermentation via Engineered Corynebacterium

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Solution Overview

Problem

Current methods for producing (R)-3-hydroxybutyric acid are inefficient, costly, and often result in racemic mixtures, requiring high temperatures, expensive catalysts, and large amounts of organic solvents, with challenges in controlling racemization and scalability for industrial use.

Innovation Solution

A biological process using genetically engineered nonpathogenic microorganisms such as Corynebacterium glutamicum to ferment carbon and nitrogen sources directly into (R)-3-hydroxybutyric acid in a one-step method, avoiding chemical synthesis and enzymatic degradation limitations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If chemical synthesis is used to produce (R)-3-hydroxybutyric acid, then high purity product can be obtained, but high temperature, high pressure, and expensive chiral metal catalysts are required

Engineering Contradiction:
Improveproduct purityVSAvoidprocess complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent replaces chemical synthesis methods with microbial fermentation to produce (R)-3-hydroxybutyric acid. Specifically, it uses engineered bacteria (such as Corynebacterium glutamicum) to biosynthesize the target compound through metabolic pathways, substituting chemical catalysts and extreme conditions with biological systems that operate under mild conditions while maintaining high optical purity

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the production parameters from extreme chemical conditions (high temperature, high pressure) to mild biological conditions (physiological temperature, atmospheric pressure). By adjusting fermentation parameters such as carbon source composition, nitrogen source, and aeration conditions, the process achieves high product purity without requiring expensive chiral metal catalysts

Inventive Principle:
Principle #35Parameter changes

2Manufacturing precision

If enzymatic degradation of poly-3-hydroxybutyrate is used, then (R)-3-hydroxybutyric acid can be produced, but large amounts of organic solvent are required and racemization control is difficult

Engineering Contradiction:
Improveoptical purityVSAvoidorganic solvent consumption
Core Design Contradiction:
Manufacturing precisionVSLoss of substance

Solution Approach 1:

The patent replaces enzymatic degradation with direct microbial fermentation. Instead of using poly-3-hydroxybutyrate depolymerase in organic solvents to break down polymer, the invention uses engineered microorganisms to directly synthesize (R)-3-hydroxybutyric acid from carbon sources through their metabolic pathways, eliminating the need for organic solvents and enzymatic reactions

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent introduces genetically engineered microorganisms as living factories that serve as intermediaries to convert carbon sources directly into (R)-3-hydroxybutyric acid. These engineered strains overexpress key enzymes in the biosynthetic pathway and lack racemization capability, ensuring high optical purity without requiring organic solvents or post-reaction racemization control

Inventive Principle:
Principle #24Intermediary (Mediator)

3Productivity

If racemic 3-hydroxybutyric acid is produced, then production cost is reduced, but the product lacks physiological activity and requires additional separation steps

Engineering Contradiction:
Improveproduction efficiencyVSAvoidoptical purity
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The patent employs asymmetric biosynthesis through genetically engineered microorganisms that naturally produce only the (R)-enantiomer. By modifying the bacterial genome to overexpress specific enzymes in the (R)-3-hydroxybutyric acid biosynthetic pathway and eliminate racemization capabilities, the process achieves high optical purity directly during fermentation, avoiding the need for subsequent separation steps

Inventive Principle:
Principle #4Asymmetry

Solution Approach 2:

The patent replaces chemical racemic synthesis followed by separation with direct biological asymmetric synthesis. The engineered microorganisms serve as living catalysts that inherently produce enantiomerically pure (R)-3-hydroxybutyric acid through their metabolic pathways, eliminating the need for chiral resolution or separation processes

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

4Manufacturing precision

If poly-3-hydroxybutyrate degradation is used, then (R)-3-hydroxybutyric acid can be obtained, but very pure starting material is required and reaction time is long

Engineering Contradiction:
Improveproduct purityVSAvoidreaction time
Core Design Contradiction:
Manufacturing precisionVSLoss of time

Solution Approach 1:

The patent inverts the traditional approach of degrading poly-3-hydroxybutyrate to produce (R)-3-hydroxybutyric acid. Instead of breaking down polymer requiring pure starting material and long reaction times, the invention uses direct microbial fermentation where engineered bacteria synthesize the target compound de novo from carbon sources through their metabolic pathways, dramatically reducing both time and material purity requirements

Inventive Principle:
Principle #13The other way round (Inversion)

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 process achieves high purity (95% or more) (R)-3-hydroxybutyric acid production without bacterial endotoxins or chemical residues, suitable for industrial scale and food-grade applications, offering a safer and more efficient alternative to traditional methods.

Implementation Method 1

a biological process using genetically engineered nonpathogenic microorganisms such as Corynebacterium glutamicum to ferment carbon and nitrogen sources directly into (R)-3-hydroxybutyric acid in a one-step method

Methodology Applied
Scientific EffectFermentation: Fermentation

Data Source

PatentUS11198890B2Preparation of (R)-3-hydroxybutyric acid or its salts by one-step fermentation
Publication Date: 2021.12.14 NANJING NUTRABUILDING BIO TECH CO LTD

AI summary

The subject invention relates to a process of preparing (R)-3-hydroxybutyric acid or a salt thereof by one-step fermentation with a nonpathogenic microorganism. The fermentation of (R)-3-hydroxybutyric acid was performed by supplying with certain carbon and nitrogen sources. These microorganisms include a Glutamic acid Bacterium HR057 strain or one type of genetically engineered Corynebacterium Glutamicum.