Triacylglycerol Production in Oleaginous Yeast via Enzyme Segmentation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The unpredictable success of upregulating functional enzymes for increasing lipid yield in oleaginous organisms, such as Yarrowia lipolytica, due to variations in genetic modifications, including the expression of diacylglycerol acyltransferase genes from different species, which often result in inconsistent lipid production levels.
Innovation Solution
A combination of genetic modifications that increase the activity of both type 1 and type 2 diacylglycerol acyltransferase genes, along with the down-regulation of triacylglycerol lipase activity, to enhance triacylglycerol production in Yarrowia lipolytica, specifically by expressing DGA1 from Rhodosporidium toruloides and DGA2 from Claviceps purpurea, and knocking out TGL3, to stabilize and increase lipid content.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If diacylglycerol acyltransferase genes from different species are expressed to increase lipid yield, then lipid production may be enhanced, but the success is unpredictable and inconsistent
Solution Approach 1:
The patent segments the diacylglycerol acyltransferase function into two separate genes: DGAT1 (type 1 DGA) and DGAT2 (type 2 DGA). By expressing both genes separately rather than relying on a single enzyme, the system achieves more predictable and consistent lipid production, as each enzyme contributes additively to the overall lipid synthesis capacity.
Solution Approach 2:
The patent combines the expression of both DGAT1 and DGAT2 genes in the same host organism (Yarrowia lipolytica). This merging of two enzyme systems working together produces a synergistic effect that increases lipid yield more reliably than expressing either enzyme alone, as demonstrated by the consistent 2-3 fold increase in lipid production observed in the transformed strains.
2Productivity
If triacylglycerol lipase activity is increased to improve lipid metabolism, then lipid breakdown is enhanced, but lipid accumulation is reduced
Solution Approach 1:
Instead of increasing triacylglycerol lipase activity to improve lipid metabolism, the patent applies the opposite approach by deleting or knocking out the TGL3 gene, which encodes a triacylglycerol lipase. This inversion of the conventional strategy (reducing rather than increasing lipase activity) prevents lipid breakdown and thereby increases net lipid accumulation in the host organism.
3Device complexity
If single gene modifications are applied to increase lipid content, then genetic engineering is simplified, but lipid production levels remain inconsistent
Solution Approach 1:
The patent segments the lipid synthesis pathway by targeting and modifying two separate genes (DGAT1 and DGAT2) rather than relying on a single gene. This segmentation allows for more precise control over lipid production, as each gene can be optimized independently, resulting in more consistent and predictable lipid accumulation levels.
Solution Approach 2:
The patent creates a composite genetic system by combining multiple gene modifications (expressing DGAT1, expressing DGAT2, and deleting TGL3) within a single host organism. This composite approach integrates multiple functional elements to achieve superior and more consistent lipid production compared to single-gene modifications.
Data Source
AI summary
Disclosed are methods and compositions for increasing the triacylglycerol content of a cell by increasing the activity of a type 1 diacylglycerol acyltransferase (i.e., DGA2) and increasing the activity of a type 2 diacylglycerol acyltransferase (i.e., DGA1). In some embodiments, the triacylglycerol content of a cell is also modified my decreasing the activity of a triacylglycerol lipase in the same cell. Also disclosed are methods and compositions for increasing the triacylglycerol content of a cell by increasing the activity of a type 1 diacylglycerol acyltransferase (i.e., DGA2), or by increasing the activity of a type 3 diacylglycerol acyltransferase (i.e., DGA3).