Urease Urea Fermentation Yeast Health Ethanol
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Solution Overview
Problem
Current ethanol fermentation processes face inefficiencies in yeast growth and ethanol production, particularly when using traditional corn-based feedstocks, due to inadequate nitrogenous nutrients and denaturation of enzymes at high temperatures, leading to suboptimal fermentation rates and product yields.
Innovation Solution
Incorporating urease and urea into the fermentation process, along with a urease-containing feedstock such as soybeans, to enhance nitrogen availability and enzyme activity, thereby improving yeast health and fermentation efficiency, and utilizing genetically modified microorganisms to produce urease for increased ethanol production and improved co-product quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If traditional corn-based feedstocks are used in ethanol fermentation, then the fermentation process is simple and cost-effective, but nitrogenous nutrients are inadequate leading to suboptimal yeast growth and fermentation rates
Solution Approach 1:
Urea is introduced as an intermediary nitrogen source that bridges the nutritional gap. The urea hydrolyzes to provide ammonia, which serves as a readily available nitrogen source for yeast, thereby improving fermentation rate without complicating the overall feedstock composition
Solution Approach 2:
The nitrogen content parameter of the feedstock is modified by adding urea. This changes the nutritional profile from nitrogen-deficient (corn-only) to nitrogen-sufficient, directly addressing the limitation of traditional corn-based feedstocks while maintaining the simplicity of the fermentation process
2Productivity
If high temperatures are used in the fermentation process, then ethanol production efficiency is improved, but enzymes are denatured leading to reduced fermentation effectiveness
Solution Approach 1:
Urea is added to the feedstock before fermentation begins, allowing it to hydrolyze and provide nitrogenous nutrients in advance. This preliminary nutritional preparation enables the yeast to thrive at higher temperatures without requiring complex enzyme systems, thus maintaining enzyme reliability while achieving high ethanol production efficiency
Solution Approach 2:
The patent replaces the need for complex enzymatic nitrogen utilization systems with a simpler chemical approach using urea hydrolysis. This substitution allows the fermentation process to operate at higher temperatures more effectively, as the urea-based nitrogen source does not rely on temperature-sensitive enzymes for its action
3Quantity of substance
If urea is added to provide nitrogenous nutrients, then yeast growth is improved, but non-protein nitrogen levels increase which may affect product quality
Solution Approach 1:
Urea serves its dual function: it provides the necessary nitrogenous nutrients for yeast growth while simultaneously acting as a source of protein nitrogen through its hydrolysis to ammonia. This self-service mechanism allows urea to fulfill its nutritional role without creating excessive non-protein nitrogen, as the ammonia produced is readily incorporated into yeast proteins
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 use of urease and urea with soybeans in ethanol fermentation increases ethanol production, enhances the protein content and essential amino acid profile of dried distiller's grains, and improves fiber conversion to ethanol, while maintaining minimal non-protein nitrogen levels and reducing residual starch, resulting in more efficient and productive fermentation processes.
Implementation Method 1
Urease catalyzes the hydrolysis of urea into ammonia and carbon dioxide
Implementation Method 2
Urease can be in reagent form, or can be produced by microbes and/or by plants
Implementation Method 3
Yeast, acting subsequent to or simultaneously with the enzymes, convert the simple sugars to ethanol and carbon dioxide
Implementation Method 4
Enzymes, whether endogenous to the grain, added to the fermenter, or produced by yeast, convert components of the feedstock into simple sugars
Data Source
AI summary
Methods, compositions, and systems for propagation and fermentation, particularly large scale operations for production of ethanol and dried distiller's grain are provided. Addition of urease and urea to propagation and/or fermentation improves yeast health, fermentation efficiency, and quality and quantity of DDG. Urease can be in reagent form or can be endogenous to the natural feedstock.