Single-Phase LPS Extraction for Higher Yield and Fewer Purification Steps
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for large-scale LPS extraction from gram-negative bacteria are inefficient, posing health and safety risks and requiring multiple purification steps, with yields ranging from 2% to 12% per unit of dry cell mass, and there is a need for improved methods achieving higher extraction efficiency.
Innovation Solution
A single-phase extraction solution comprising 2 mM to 30 mM NaOAc, 0.4% to 3.5% water, methanol, and chloroform is used to extract LPS from gram-negative bacterial cells, with a temperature range of 35°C to 65°C and reflux conditions, followed by ethanol and methanol washes to reduce phospholipid impurities, and subsequent evaporation to obtain a water-dispersed LPS composition.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If traditional extraction methods (Galanos or Chen) are used, then LPS can be extracted from gram-negative bacteria, but the extraction efficiency is low (2%-12% yield per unit dry cell mass) and multiple purification steps are required
Solution Approach 1:
The patent changes the chemical parameters of the extraction solution by incorporating water (0.1-10% v/v) into the chloroform-methanol system, and adjusts the molar ratio of chloroform to methanol to between 1:1 and 4:1. These parameter modifications enable single-phase extraction that achieves superior LPS recovery (40-60% yield) while eliminating the need for multiple purification steps, directly resolving the contradiction between extraction efficiency and process complexity
Solution Approach 2:
The patent creates a composite extraction solution system combining chloroform, methanol, and water in specific proportions. This composite solvent system leverages the complementary properties of each component: chloroform for LPS solubility, methanol for phospholipid removal, and water for enhanced LPS recovery. The synergistic interaction of these components enables high-efficiency single-phase extraction, resolving the technical contradiction by achieving both high productivity and simplified process complexity
2Ease of manufacture
If Galanos method is used for LPS extraction, then LPS can be obtained, but the method uses solvent mixtures (phenol:chloroform:petroleum ether) that pose health and safety concerns and is not suitable for large scale production
Solution Approach 1:
The patent modifies the solvent system parameters by replacing phenol and petroleum ether with a safer chloroform-methanol-water mixture. The optimized water content (0.1-10% v/v) and chloroform:methanol ratio (1:1 to 4:1) create a single-phase system that maintains extraction effectiveness while eliminating the health and safety hazards associated with phenol and petroleum ether, enabling safe large-scale production
Solution Approach 2:
The patent employs a solvent system that is easier to handle and dispose of safely compared to phenol-based methods. The chloroform-methanol-water mixture allows for simpler waste management and reduced safety precautions during handling, making the process more suitable for industrial-scale production where safety and ease of manufacture are critical
3Manufacturing precision
If Chen method is used for LPS extraction, then LPS can be extracted with phospholipid removal, but multiple precipitation steps are required to obtain LPS of sufficient purity
Solution Approach 1:
The patent changes the extraction phase structure from multi-phase (Chen method) to single-phase by incorporating water into the chloroform-methanol system. This parameter change allows LPS and phospholipids to separate in a single extraction step with LPS preferentially partitioning into the organic phase, achieving both high purity and high extraction efficiency without requiring multiple precipitation steps
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 method achieves a significant increase in LPS yield, up to 45% improvement per unit mass of dried cells, with higher extraction efficiency and reduced impurities, producing a more effective immunogenic composition.
Implementation Method 1
A single-phase extraction solution comprising 2 mM to 30 mM NaOAc, 0.4% to 3.5% water, methanol, and chloroform is used to extract LPS from gram-negative bacterial cells
Implementation Method 2
extracting the cells with a solution comprising chloroform and methanol, thereby yielding a solution of LPS in chloroform and methanol (CM)
Implementation Method 3
followed by ethanol and methanol washes to reduce phospholipid impurities, and subsequent evaporation to obtain a water-dispersed LPS composition
Data Source
Figure 1
Figure 2
Figure 3A
AI summary
A method of lipopolysaccharide (LPS) extraction from gram negative bacterial cells is provided, said method comprising a step of extracting LPS from the gram negative bacterial cell in a LPS extraction solution comprising a salt, water, an alcohol, and a further organic solvent. Compositions and uses of the extracted LPS are also provided.