Modified Microorganism for Low-Salt Ectoine Production
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for producing ectoine, such as using halophilic bacteria, face challenges including high salt requirements, equipment corrosion, complex downstream processing, and reduced yield due to catabolism, necessitating the development of more efficient and cost-effective production methods, especially in low-salt conditions.
Innovation Solution
A genetically modified microorganism with specific modifications, including expression of ectA, ectB, and ectC genes, deletion of pykA and pykF genes, and reduction of citrate synthase activity, is used for improved ectoine production, allowing for production in low-salt conditions and enhanced yield.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If halophilic bacteria are used for ectoine production under high salt conditions, then ectoine can be produced through natural metabolic pathways, but equipment corrosion occurs and downstream processing complexity increases
Solution Approach 1:
The patent changes the osmolarity parameter from high salt conditions to low salt conditions by using non-halophilic bacteria. This is achieved through genetic modification of the metabolic pathway to produce ectoine independently of high osmolarity, thereby eliminating equipment corrosion and simplifying downstream processing while maintaining productivity
Solution Approach 2:
The patent replaces expensive and maintenance-intensive halophilic bacteria systems with cheaper non-halophilic bacteria that do not require high salt conditions. This substitution eliminates the need for corrosion-resistant equipment and complex desalting processes, reducing overall production costs
2Productivity
If halophilic bacteria are subjected to alternating high and low salt conditions for ectoine production, then ectoine can be induced and released, but production becomes discontinuous and yield is reduced due to catabolism
Solution Approach 1:
The patent extracts the dependency of ectoine production from osmolarity changes by genetically modifying non-halophilic bacteria to constitutively express the ectABC pathway. This eliminates the need for alternating salt conditions and continuous induction cycles, enabling continuous production without catabolic losses
Solution Approach 2:
The patent achieves continuous ectoine production by engineering bacteria with a constitutively active metabolic pathway that operates independently of environmental osmolarity changes. This continuous production mode eliminates the stop-start nature of induction-release cycles and prevents ectoine catabolism, maximizing productivity
3Ease of manufacture
If genetic modification is applied to non-halophilic bacteria for ectoine production, then high salt conditions can be avoided, but ectoine yield and productivity remain equivalent to halophilic bacteria
Solution Approach 1:
The patent applies preliminary genetic modifications to non-halophilic bacteria to optimize the ectoine metabolic pathway before production. This includes deleting genes encoding competing enzymes (pykA, pykF, gltA) and overexpressing key pathway enzymes (ectA, ectB, ectC, aspartokinase, homoserine transmethaldehyde dehydrogenase), thereby pre-configuring the bacteria for high-yield ectoine production under simple conditions
Solution Approach 2:
The patent applies localized genetic modifications specifically to the ectoine metabolic pathway and related competing pathways, rather than globally modifying the entire bacterial metabolism. This targeted approach optimizes ectoine yield by enhancing specific enzymatic steps while maintaining overall cellular function, achieving high productivity under simplified conditions
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 modified microorganism achieves improved ectoine production with reduced costs and simplified processing, overcoming the limitations of traditional methods by enabling efficient production in low-salt conditions and increasing yield.
Implementation Method 1
In halophilic microorganisms, ectoine is synthesized from the L-aspartate-β-semialdehyde (ASA) precursor in three steps with the enzymes EctA, EctB, and EctC. The diaminobutyric acid transaminase (EctB) initially converts ASA to L-2,4-diaminobutyric acid (DABA). DABA is then converted to Nγ-acetyl-L-2,4-diaminobutyric acid by the DABA acetyltransferase (EctA). Finally, ectoine synthase (EctC) converts Nγ-acetyl-L-2,4-diaminobutyric acid to ectoine.
Data Source
AI summary
The present invention relates to a microorganism genetically modified for production of ectoine, wherein said microorganism comprises the following modifications: expression of a heterologous gene ectA encoding a diaminobutyric acid acetyltransferase having at least 90% similarity with SEQ ID NO: 1, SEQ ID NO: 2, SEQ ID NO: 3, SEQ ID NO: 4 or SEQ ID NO: 5, a heterologous gene ectB encoding a diaminobutyric acid aminotransferase having at least 90% similarity with SEQ ID NO: 6, SEQ ID NO: 7, SEQ ID NO: 8, SEQ ID NO: 9 or SEQ ID NO: 10, a heterologous gene ectC encoding an ectoine synthase having at least 90% similarity with SEQ ID NO: 11, SEQ ID NO: 12, SEQ ID NO: 13, SEQ ID NO: 14 or SEQ ID NO: 15 and deletion of pykA and pykF genes. The present invention also relates to a method for the production of ectoine using said microorganism.