L-Amino Acid Fermentation via BudA Gene Deletion

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Solution Overview

Problem

Current methods for producing L-amino acids, such as L-glutamic acid, through fermentation using bacteria are limited in efficiency and require improvement to enhance production yields.

Innovation Solution

Modifying bacteria belonging to the family Enterobacteriaceae to reduce the activity of specific proteins like BudA, BudB, BudC, PAJ_3461, PAJ_3462, and PAJ_3463, which are involved in competing metabolic pathways, thereby enhancing the bacterium's L-amino acid-producing ability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If conventional fermentation methods using wild-type or mutant bacteria are used, then the process is simple, but the L-amino acid production efficiency is limited

Engineering Contradiction:
ImproveL-amino acid production efficiencyVSAvoidbacterial modification complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent extracts and removes the competing metabolic pathway by deleting the budA gene, which encodes acetolactate decarboxylase. This extraction of the harmful metabolic route redirects carbon flux toward L-amino acid production, resolving the contradiction between production efficiency and genetic modification complexity by targeting a single key gene rather than multiple pathways

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent changes the metabolic parameters of the bacterium by deleting the budA gene and overexpressing L-amino acid synthesis-related genes. This parameter change in the bacterial metabolism shifts the balance from low-efficiency wild-type production to high-efficiency L-amino acid production, achieving improved productivity with controlled genetic modifications

Inventive Principle:
Principle #35Parameter changes

2Quantity of substance

If multiple gene modifications are introduced to improve L-amino acid production, then production yield increases, but the difficulty of strain construction increases

Engineering Contradiction:
ImproveL-amino acid yieldVSAvoidstrain construction difficulty
Core Design Contradiction:
Quantity of substanceVSEase of manufacture

Solution Approach 1:

The patent segments the metabolic improvement strategy into two distinct parts: (1) deletion of the budA gene to remove the competing pathway, and (2) overexpression of L-amino acid synthesis genes. This segmentation allows each modification to be optimized independently and combined systematically, making the overall strain construction process more manageable despite involving multiple genetic changes

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent performs preliminary identification and validation of target genes (budA deletion and L-amino acid synthesis gene overexpression) before full-scale strain construction. This preliminary action includes screening and confirming the effectiveness of each genetic modification individually, which simplifies the overall manufacturing process by avoiding trial-and-error approaches

Inventive Principle:
Principle #10Preliminary action

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

The modified bacteria exhibit improved L-amino acid-producing capabilities, leading to increased accumulation and yield of L-amino acids like L-glutamic acid in the culture medium and bacterial cells.

Implementation Method 1

L-Amino acids are industrially produced by, for example, fermentation using microorganisms such as bacteria having an L-amino acid-producing ability

Methodology Applied
Scientific EffectFermentation: Fermentation

Data Source

PatentEP4567123A2Method for producing l-amino acid
Publication Date: 2025.06.11 AJINOMOTO CO INC

AI summary

A method for producing an L-amino acid such as L-glutamic acid is provided. An L-amino acid is produced by culturing in a culture medium a bacterium belonging to the family Enterobacteriaceae and having an L-amino acid-producing ability, and collecting the L-amino acid from the culture medium and/or cells of the bacterium, wherein the bacterium has been modified to have one or more modifications selected from the modifications (A) to (F) shown below: (A) modification of reducing the activity of a BudA protein; (B) modification of reducing the activity of a BudB protein; (C) modification of reducing the activity of a BudC protein; (D) modification of reducing the activity of a PAJ_3461 protein; (E) modification of reducing the activity of a PAJ_3462 protein; and (F) modification of reducing the activity of a PAJ_3463 protein.