Genetically Modified Yeasts for Lactate Consumption in Fermentation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current industrial yeast fermentation processes cannot efficiently utilize lactate as a carbon source, especially in the presence of glucose, leading to significant amounts of lactate remaining unconsumed in fermentation substrates like corn process streams.
Innovation Solution
Genetically modified yeasts, such as Saccharomyces cerevisiae, are developed to express heterologous genes like monocarboxylate/proton symporters and lactate dehydrogenases, enabling them to consume lactate and produce ethanol, even in the presence of glucose, with enhanced lactate consumption rates.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If conventional yeasts are used in fermentation processes, then glucose can be efficiently consumed to produce ethanol, but lactate remains unconsumed and cannot be utilized as a carbon source
Solution Approach 1:
The patent applies parameter changes by modifying the yeast's metabolic capabilities through genetic engineering. Specifically, heterologous genes encoding lactate dehydrogenase and monocarboxylate transporters are introduced to change the yeast's ability to transport and metabolize lactate, transforming it from an unusable substrate to an efficient carbon source for ethanol production
Solution Approach 2:
The genetically modified yeast performs self-service by autonomously consuming lactate that would otherwise remain waste in the fermentation medium. The introduced metabolic pathways enable the yeast to independently utilize lactate without requiring external intervention or separate processing steps
2Quantity of substance
If lactate is present in fermentation substrates like corn process streams, then substrate utilization is limited, but removing lactate would increase process complexity and cost
Solution Approach 1:
The patent converts the harmful or wasted lactate component in corn process streams into a beneficial carbon source for ethanol production. By enabling the yeast to metabolize lactate, the previously problematic substance becomes a valuable resource that increases overall carbon source utilization without requiring substrate pretreatment or removal steps
3Quantity of substance
If yeasts are engineered to consume lactate, then lactate utilization improves, but the presence of glucose may inhibit lactate consumption in conventional yeasts
Solution Approach 1:
The genetically modified yeast achieves multi-functionality by simultaneously consuming both glucose and lactate as carbon sources. The introduced metabolic pathways enable the yeast to perform multiple functions: traditional glucose fermentation and novel lactate utilization, allowing flexible adaptation to mixed substrate conditions without inhibition
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 genetically modified yeasts effectively consume lactate and produce ethanol at higher rates, improving fermentation yields and efficiency by utilizing lactate as a carbon source, thereby enhancing the utilization of substrates like corn process streams.
Implementation Method 1
the yeast is transformed to express a heterologous monocarboxylate/proton symporter, e.g., a JEN1 symporter
Implementation Method 2
the yeast is transformed to express one or more heterologous genes encoding a lactate dehydrogenase (cytochrome) (EC 1.1.2.3 or 1.1.2.4)
Implementation Method 3
the yeasts can use lactate as a carbon source to form a fermentation product... In some embodiments, the fermentation product is ethanol (EtOH)
Data Source
AI summary
The present invention relates to genetically modified yeasts that can use lactate as a carbon source to produce a fermentation product. In one aspect, the yeasts can consume glucose and lactate simultaneously to produce ethanol. In one aspect, the genetically modified yeast is transformed to include a monocarboxylic/monocarboxylate transporter. In one aspect, the yeast can include one or more heterologous genes encoding lactate dehydrogenase (cytochrome) (EC 1.1.2.3 and/or 1.1.2.4).