Novel promoter and l-amino acid production method using same

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Solution Overview

Problem

Existing methods for producing L-glutamic acid through microbial fermentation result in high lactic acid production, which negatively affects the taste of the fermented product due to its sour taste, necessitating the regulation of lactic acid production.

Innovation Solution

A novel polynucleotide with a modified nucleotide sequence at position 37 (T substituted with G) is introduced into the lactate dehydrogenase promoter, increasing L-glutamic acid production and decreasing lactic acid production in Corynebacterium microorganisms.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If conventional fermentation methods are used to produce L-glutamic acid, then L-glutamic acid production is achieved, but lactic acid production increases causing sour taste and decreased palatability

Engineering Contradiction:
ImproveL-glutamic acid productionVSAvoidlactic acid production
Core Design Contradiction:
Quantity of substanceVSObject-generated harmful factors

Solution Approach 1:

The patent applies parameter changes by modifying the promoter sequence of the lactate dehydrogenase gene at position 37 (T to G substitution). This nucleotide parameter change alters the promoter's transcriptional activity, thereby reducing lactic acid production while maintaining or enhancing L-glutamic acid production. The specific parameter modification in the genetic sequence directly addresses the contradiction between producing the desired amino acid and minimizing the harmful organic acid byproduct.

Inventive Principle:
Principle #35Parameter changes

2Productivity

If lactic acid production is increased in fermentation, then fermentation efficiency is improved, but the sour taste increases and palatability decreases

Engineering Contradiction:
Improvefermentation efficiencyVSAvoidsour taste
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The invention modifies the promoter parameter of the lactate dehydrogenase gene by substituting thymine (T) with guanine (G) at position 37. This parameter change in the genetic sequence alters the transcriptional regulation, thereby controlling lactic acid production levels during fermentation. The modification maintains fermentation efficiency for L-glutamic acid production while reducing lactic acid accumulation to acceptable levels, thus preserving product palatability.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP3763819B1Novel promoter and l-amino acid production method using same
Publication Date: 2025.11.19 CJ CHEILJEDANG CORP

AI summary

The present disclosure relates to a novel promoter and a method for producing L-amino acids using the promoter, and more specifically, to a novel polynucleotide having promoter activity, a vector and a microorganism of the genus Corynebacterium comprising the polynucleotide, a method for producing L-amino acids using the microorganism, and a fermented composition.