Fermentation Stirring Impeller Power Density Control

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Solution Overview

Problem

Current methods for producing L-amino acids and nucleic acids through fermentation are inefficient and costly, particularly when crystals are precipitated in the medium, resulting in lower productivity compared to traditional fermentation methods without crystal precipitation.

Innovation Solution

Control the power density of the stirring impeller in the fermentation process to a specific range (0.5 kW/m³ to 2.4 kW/m³) after crystal precipitation or seed crystal addition to enhance the productivity of L-amino acid or nucleic acid production, using microorganisms such as those belonging to the family Enterobacteriaceae or coryneform bacteria.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If crystals are precipitated in the fermentation medium, then the productivity is improved, but the manufacturing complexity increases due to crystal separation and purification requirements

Engineering Contradiction:
ImproveproductivityVSAvoidmanufacturing complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent applies parameter changes by optimizing the power density of the stirring impeller to a specific range (0.5-2.4 kW/m³) to control crystal precipitation. This parameter optimization enables efficient crystal formation while maintaining manageable manufacturing complexity through controlled fermentation conditions.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent replaces complex mechanical crystal separation systems with a biochemical approach by using specific stirring conditions to promote in-situ crystal precipitation. This substitution reduces the need for complex mechanical separation equipment while maintaining high productivity.

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

2Loss of energy

If the power density of stirring impeller is reduced, then energy consumption is lowered, but the fermentation efficiency deteriorates

Engineering Contradiction:
Improveenergy consumptionVSAvoidfermentation efficiency
Core Design Contradiction:
Loss of energyVSProductivity

Solution Approach 1:

The patent identifies an optimal parameter range (0.5-2.4 kW/m³) for stirring impeller power density that balances energy consumption and fermentation efficiency. This parameter optimization allows the system to achieve both low energy loss and high productivity simultaneously.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent converts the potentially harmful effect of reduced stirring power (which could cause poor mixing) into a beneficial condition for crystal precipitation. By controlling power density within the optimal range, the system achieves efficient crystal formation while maintaining adequate mixing, thus turning a potential disadvantage into an advantage.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

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 approach significantly improves the productivity of L-amino acid or nucleic acid production by optimizing the stirring conditions, allowing for efficient accumulation and precipitation of target substances in the fermentation medium, thereby overcoming the inefficiencies of traditional methods.

Implementation Method 1

a fermentation tank provided with a stirring impeller

Methodology Applied
Scientific EffectStirring: Stirring

Implementation Method 2

producing an L-amino acid or nucleic acid by culturing a microorganism having an ability to produce the L-amino acid or nucleic acid in a liquid medium

Methodology Applied
Scientific EffectFermentation: Fermentation

Implementation Method 3

produce and accumulate crystals of the L-amino acid or nucleic acid in the medium

Methodology Applied
Scientific EffectPrecipitation: Precipitation

Implementation Method 4

crystals of amino acid having a mean particle diameter of 1 to 120 μm are added to medium

Methodology Applied
Scientific EffectCrystallization: Crystallisation

Data Source

PatentEP2130924B1Method for production of l-amino acid or nucleic acid
Publication Date: 2015.09.02 AJINOMOTO CO INC
  • EP2130924B1 patent drawingFigure 1
  • EP2130924B1 patent drawingFigure 2~3
  • EP2130924B1 patent drawingFigure 4

AI summary

In a method for producing an L-amino acid or a nucleic acid by culturing a microorganism having an ability to produce the L-amino acid or nucleic acid in a liquid medium contained in a fermentation tank provided with a stirring impeller with optionally adding seed crystals to the medium as required to produce and accumulate crystals of the L-amino acid or nucleic acid in the medium, and collecting crystals of the L-amino acid or nucleic acid from culture, power density of the stirring impeller is controlled to be 2.4 kW/m3 or lower after precipitation of the crystals or addition of the seed crystals.