Aldehyde Dehydrogenase in Fermentation for Ethanol Yield

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Solution Overview

Problem

The production of ethanol from starch-containing materials through fermentation is costly due to low yields, necessitating processes that enhance ethanol production efficiency.

Innovation Solution

Incorporating aldehyde dehydrogenase enzymes from the EC 1.2.1.3, EC 1.2.1.4, and EC 1.2.1.5 classes into the fermentation medium, alongside saccharifying starch-containing materials below their initial gelatinization temperature and using yeast as the fermenting organism, to optimize ethanol yield.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If conventional fermentation processes are used to produce ethanol from starch-containing materials, then the process is simple and straightforward, but the ethanol yield is low and production costs are high

Engineering Contradiction:
Improveethanol yieldVSAvoidprocess complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent introduces aldehyde dehydrogenase enzyme as an intermediary substance in the fermentation process. This enzyme catalyzes the conversion of acetaldehyde to ethanol, thereby increasing the ethanol yield. The enzyme acts as a mediator that enhances the existing fermentation process rather than replacing it, resolving the contradiction by improving productivity without fundamentally changing the process architecture.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent modifies the fermentation process by changing the chemical parameters of the reaction environment. Specifically, it utilizes the optimal working conditions of aldehyde dehydrogenase enzyme (pH, temperature) to enhance ethanol production. By adjusting these parameters to match the enzyme's optimal performance, the process achieves higher ethanol yield while maintaining operational simplicity.

Inventive Principle:
Principle #35Parameter changes

2Productivity

If aldehyde dehydrogenase enzyme is added to the fermentation medium, then ethanol production is enhanced, but the process requires additional enzyme addition steps

Engineering Contradiction:
Improveethanol production rateVSAvoidprocess simplicity
Core Design Contradiction:
ProductivityVSEase of manufacture

Solution Approach 1:

The patent employs a self-service approach by utilizing the yeast's own metabolic capabilities. The aldehyde dehydrogenase enzyme is expressed by the yeast itself during the fermentation process, eliminating the need for external enzyme addition. This resolves the contradiction by maintaining process simplicity while achieving enhanced ethanol production through the organism's self-service metabolic function.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent leverages the multi-functionality of the yeast organism, which simultaneously performs sugar fermentation to ethanol and produces aldehyde dehydrogenase enzyme. This universal approach allows a single organism to fulfill multiple roles in the process, enhancing ethanol production without requiring separate enzyme addition steps, thus maintaining ease of manufacture.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Productivity

If aldehyde dehydrogenase is used to regenerate NAD(P)+, then fermentation efficiency is improved, but the process requires precise control of redox balance

Engineering Contradiction:
Improvefermentation efficiencyVSAvoidprocess control complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent applies self-service by allowing the yeast to automatically regulate its own redox balance through the natural action of aldehyde dehydrogenase. The enzyme continuously converts acetaldehyde to ethanol, regenerating NAD(P)+ as needed during fermentation. This self-regulating mechanism improves fermentation efficiency without requiring external control systems, resolving the contradiction by maintaining simplicity while enhancing productivity.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent utilizes an inherent feedback mechanism where the yeast's metabolic state automatically adjusts the activity of aldehyde dehydrogenase based on the cellular redox conditions. When NAD(P)+ is depleted, the enzyme activity increases to regenerate the cofactor. This built-in feedback loop improves fermentation efficiency while avoiding the need for complex external control systems.

Inventive Principle:
Principle #23Feedback

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 regenerates NAD(P)+, increases ethanol production, and enhances yeast growth, thereby reducing production costs and improving fermentation efficiency.

Implementation Method 1

one or more aldehyde dehydrogenases selected from the group of enzymes classified in EC 1.2.1.3, EC 1.2.1.4 and EC 1.2.1.5 are added to the fermentation medium

Methodology Applied
Scientific EffectEnzyme catalysis: Enzyme

Implementation Method 2

The presence of an excess amount of acetic acid and NADH+ may promote a reverse reaction that generates acetaldehyde which can then be converted to ethanol

Methodology Applied
Scientific EffectOxidation: Oxidation

Implementation Method 3

fermenting using a fermenting organism, wherein the fermenting organism is a yeast

Methodology Applied
Scientific EffectFermentation: Fermentation

Implementation Method 4

A vast number of processes of producing fermentation products, such as ethanol, by fermentation of sugars provided by degradation of starch-containing and/or lignocellulose-containing material are known in the art

Methodology Applied
Scientific EffectGlycolysis:

Implementation Method 5

saccharifying starch-containing material at a temperature below the initial gelatinization temperature of said starch-containing material

Methodology Applied
Scientific EffectHydrolysis: Hydrolysis

Data Source

PatentEP2245172B1Producing fermentation products in the presence of aldehyde dehydrogenase
Publication Date: 2017.12.13 NOVOZYMES AS
  • EP2245172B1 patent drawingFigure 1
  • EP2245172B1 patent drawingFigure 2
  • EP2245172B1 patent drawing

AI summary

The invention relates to a process of fermenting plant material in a fermentation medium into a fermentation product using a fermenting organism, wherein one or more aldehyde dehydrogenases are present in the fermentation medium.