Yeast Culture pH Adjustment for Glutamic Acid Accumulation

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Solution Overview

Problem

Current methods for producing yeast extracts with high glutamic acid content are complex, often requiring decomposition treatments like acid-hydrolysis, and result in low concentrations of free glutamic acid, poor safety, and palatability issues, with existing products typically containing around 10% glutamic acid.

Innovation Solution

A method involving culturing yeast in a stationary growth phase with a pH adjusted to 7.5 or higher and lower than 11, using an alkaline substance, to increase the content of free glutamic acid, resulting in a yeast extract with 20% to 35% free glutamic acid by weight.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If conventional decomposition treatments like acid-hydrolysis are used to produce yeast extracts, then glutamic acid can be released, but the process becomes complex and safety issues arise

Engineering Contradiction:
Improveglutamic acid contentVSAvoidprocess complexity
Core Design Contradiction:
Quantity of substanceVSDevice complexity

Solution Approach 1:

The invention changes the pH parameter of the culture medium to alkaline conditions (pH 7.5-11.0) during the stationary growth phase, which fundamentally alters the metabolic pathway of yeast to directly accumulate glutamic acid without requiring decomposition treatments. This parameter change eliminates complex acid-hydrolysis steps while safely producing high glutamic acid content yeast extracts

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention extracts and utilizes the natural glutamic acid accumulation capability of yeast under alkaline conditions, taking out the need for decomposition treatments entirely. By cultivating yeast in alkaline medium during stationary phase, glutamic acid is directly produced and accumulated in the yeast cells, which can then be extracted through simple filtration and drying without complex hydrolysis processes

Inventive Principle:
Principle #2Taking out (Extraction)

2Quantity of substance

If conventional yeast extracts are produced, then they contain glutamic acid, but the concentration is low (around 10%)

Engineering Contradiction:
Improveglutamic acid concentrationVSAvoidglutamic acid production efficiency
Core Design Contradiction:
Quantity of substanceVSProductivity

Solution Approach 1:

By changing the pH parameter to alkaline conditions (7.5-11.0) during stationary growth phase, the invention achieves a more than doubling of glutamic acid concentration from the conventional 10% to 20-35%, while maintaining simple cultivation conditions and achieving high productivity without requiring complex multi-step processes

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention performs preliminary action by adjusting the pH to alkaline conditions before the yeast enters the stationary growth phase, preparing the metabolic environment in advance so that when stationary phase is reached, the yeast is primed to accumulate glutamic acid efficiently, resulting in high concentration and high productivity

Inventive Principle:
Principle #10Preliminary action

3Quantity of substance

If genetic modification is used to increase glutamic acid content, then production can be enhanced, but safety and palatability issues arise

Engineering Contradiction:
Improveglutamic acid contentVSAvoidsafety and palatability
Core Design Contradiction:
Quantity of substanceVSReliability

Solution Approach 1:

The invention uses parameter change (pH adjustment to alkaline conditions) rather than genetic modification to enhance glutamic acid content. This physical-chemical approach maintains the natural status of the yeast, ensuring safety and palatability while achieving high glutamic acid content (20-35%) through controlled metabolic conditions during stationary growth phase

Inventive Principle:
Principle #35Parameter changes

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 method significantly increases the free glutamic acid content in yeast and yeast extracts, achieving concentrations not previously reported, enhancing the gustatory properties and simplifying the production process without genetic modification, ensuring safety and palatability.

Implementation Method 1

a method for culturing a yeast, including a step of subjecting a yeast in a stationary growth phase to liquid culture under the conditions that the pH of a liquid medium is 7.5 or higher and lower than 11

Methodology Applied
Scientific EffectMetabolic activity: Fermentation

Data Source

PatentEP3385369B1Method for producing yeast with high glutamic acid content
Publication Date: 2021.06.09 ASAHI GRP HLDG LTD
  • EP3385369B1 patent drawingFigure 1~2
  • EP3385369B1 patent drawingFigure 3
  • EP3385369B1 patent drawing

AI summary

Provided is a method for producing a yeast containing glutamic acid at a high concentration. In the method for culturing a yeast, a yeast in a stationary growth phase is subjected to liquid culture under the conditions that the pH of a liquid medium is 7.5 or higher and lower than 11. After the pH of the liquid medium for the yeast in a stationary growth phase is adjusted to 7.5 or higher and lower than 11, the yeast is further cultured, whereby a yeast with a high glutamic acid content can be produced. In the invention, as the yeast, Saccharomyces cerevisiae or Candida utilis can be used. Therefore, by using the yeast with a high glutamic acid content obtained by the above-said method and the extract obtained by extraction from the yeast, a seasoning composition and a food or drink with a high glutamic acid content can be provided.