Genetically Engineered Bacterium for High-Yield Sialyllactose Production
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for producing sialyllactose, such as chemical and enzymatic synthesis, face challenges like low yield and high production costs, while microbial metabolic synthesis using synthetic biology is more economical but requires improvements in yield and efficiency.
Innovation Solution
A genetically engineered Escherichia coli strain is developed using CRISPR/Cas9 technology to knock out N-acetylneuraminic acid catabolic pathways, enabling high-yield production of sialyllactose by integrating multiple copies of sialic acid synthase genes and disabling catabolic pathways, allowing for self-metabolism with a cheap carbon source.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If chemical synthesis or enzymatic synthesis is used to produce sialyllactose, then production cost is reduced, but yield is low and production complexity increases
Solution Approach 1:
The patent extracts and removes the catabolic pathway genes (nanAEKT) from the bacterial genome using CRISPR/Cas9 technology, separating the synthetic pathway from the degradative pathway. This extraction prevents the breakdown of N-acetylneuraminic acid and enables high-yield production of sialyllactose without the complexity of managing multiple pathway interactions.
Solution Approach 2:
The patent segments the metabolic pathway by deleting specific catabolic genes (nanAEKT) while retaining the synthetic pathway genes. This segmentation allows the synthetic pathway to operate independently and efficiently, improving yield by preventing interference from the catabolic pathway.
2Productivity
If multiple genes are integrated into the genome for sialic acid synthesis, then production cost decreases, but yield remains low
Solution Approach 1:
The patent converts the harmful effect of the catabolic pathway (which breaks down N-acetylneuraminic acid) into a benefit by selectively deleting its genes. This eliminates the harmful degradation function, allowing the synthetic pathway to operate at high efficiency and produce substantial yields of sialyllactose.
Solution Approach 2:
The patent changes the metabolic parameters of the bacterial system by deleting specific genes (nanAEKT) that controlled the catabolic pathway. This genetic parameter change shifts the metabolic flux entirely toward sialic acid synthesis, dramatically improving yield while maintaining cost-effectiveness through simplified genetic engineering.
3Productivity
If catabolic pathway is retained in the bacterium, then metabolic flexibility is maintained, but production efficiency decreases due to resource consumption
Solution Approach 1:
The patent extracts the catabolic pathway genes (nanAEKT) from the bacterial genome, removing the function that consumes resources to break down N-acetylneuraminic acid. This extraction redirects all metabolic resources toward the synthesis of sialyllactose, dramatically improving production efficiency and reducing unnecessary resource consumption.
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 engineered bacterium achieves a higher yield of sialyllactose, reaching 2.5 to 3 g/L after 24 hours of fermentation, while using a single cheap exogenous carbon source, thereby reducing production costs.
Implementation Method 1
sialic acid (SA) can be synthesized by biosynthesis using glucose as a substrate
Implementation Method 2
using the genetically engineered bacterium to produce sialyllactose... after 24 hours of fermentation
Data Source
AI summary
The invention discloses a genetically engineered bacterium and its application in the preparation of sialyllactose. The genetically engineered bacterium has an N-acetylneuraminic acid biosynthesis pathway, includes multiple copies of a gene neuB for encoding sialic acid synthase, and the gene neuB is initiated for expression by a strong promoter. Using the genetically engineered bacteria of the invention to produce sialyllactose has the advantages of high yield and low overall cost.