Poly-L-lysine
Preservatives
Amino Acids
25104-18-1
(C₆H₁₂N₂O)_n
$158.22 ~ $237.33
Food
Free sample from 100g(NF)
One unit of:10kg/carton
One unit of:10kg/carton
10kg/carton
Product Info
What is Poly-L-lysine?
Poly-L-lysine is a natural, cationic polypeptide produced by fermentation, widely used as a broad-spectrum antimicrobial food preservative to extend shelf life by inhibiting bacteria, yeast, and molds.
How is Poly-L-lysine made?
| Step No. | Production Stage | Key Action | Control Point & Note |
|---|---|---|---|
| 1 | Inoculum Development | Cultivate a pure, high-yield microbial strain (e.g., Streptomyces albulus) in a seed flask to generate a sufficient cell mass for the main fermenter. | Control Point: Strain purity, culture medium composition, temperature, and agitation. Note: Maintaining strict aseptic conditions is critical to prevent contamination. |
| 2 | Fermentation | Transfer the inoculum to a large-scale bioreactor. Provide a nutrient-rich medium and control environmental parameters to promote microbial growth and poly-L-lysine production. | Control Point: pH, temperature, dissolved oxygen (DO) level, and nutrient feeding strategy. Note: This stage determines the final product yield and can last for several days. |
| 3 | Harvest & Cell Separation | Separate the microbial cells (biomass) from the culture broth containing the extracellular poly-L-lysine. | Control Point: Centrifugation speed and time or filtration membrane pore size. Note: Efficient separation of the supernatant is crucial for maximizing recovery in the purification steps. |
| 4 | Primary Purification | Pass the clarified broth through a cation-exchange chromatography column. The positively charged poly-L-lysine binds to the resin while impurities are washed away. | Control Point: pH and conductivity of the loading buffer, resin capacity, and flow rate. Note: This is the primary capture step that significantly increases product concentration and purity. |
| 5 | Elution & Desalting | Wash the column with a high-salt buffer to elute (release) the bound poly-L-lysine. The resulting saline solution is then desalted and concentrated, typically via ultrafiltration. | Control Point: Elution buffer salt concentration, pH, and ultrafiltration membrane cutoff. Note: This step isolates the product and prepares it for final processing. |
| 6 | Sterile Filtration | Pass the purified and concentrated poly-L-lysine solution through a sterile-grade filter to remove any remaining microorganisms. | Control Point: Filter pore size (typically 0.22 µm) and integrity testing. Note: This is a critical step to ensure the microbiological safety of the final product. |
| 7 | Drying | Convert the sterile solution into a stable powder using lyophilization (freeze-drying) or spray drying. | Control Point: Freezing rate, vacuum pressure, and shelf temperature (for lyophilization). Inlet/outlet temperature (for spray drying). Note: Proper drying is essential for product long-term stability and handling. |
| 8 | Quality Control & Packaging | Test the final powder for identity, purity (HPLC), molecular weight, moisture content, and microbial limits to ensure it meets specifications. Package in sealed, moisture-proof containers. | Control Point: Conformance to all pre-defined product specifications. Packaging integrity and environmental conditions. Note: Each batch must be accompanied by a Certificate of Analysis (CoA). |
Technical Specifications
| CAS Number | 25104-18-1 |
| Chemical Formula | (C₆H₁₂N₂O)_n |
| Solubility | water soluble, slightly soluble in ethanol |
| Storage Conditions | cool, dry, dark, room temp |
| Shelf Life | 24 Months |
Applications & Usage
Common Applications:
food
cosmetics
daily chemicals
medicine
Mechanism of action:
| Parameter | Poly-L-lysine |
|---|---|
| Functional Category | Antimicrobial Agent; Natural Preservative. |
| Key Ingredients | ε-Poly-L-lysine (ε-PL), a homopolymer of the essential amino acid L-lysine produced by microbial fermentation. |
| Mechanism of Action | The highly cationic ε-PL electrostatically adsorbs to the negatively charged cell surfaces of bacteria, fungi, and yeasts. This disrupts cell membrane integrity, causing leakage of intracellular components, inhibition of cellular metabolism, and ultimately, cell death. |
| Application Effect in Product | Provides broad-spectrum inhibition of spoilage and pathogenic microorganisms. Extends shelf life in foods like cooked rice, sauces, tofu, and beverages with minimal impact on flavor or color. Offers thermal stability for use in pasteurized or cooked products. |
Comparison:
| Product Name | Category/Type | Key Features | Strengths (vs peers) | Weaknesses (vs peers) | Best Use Cases | Why Choose |
|---|---|---|---|---|---|---|
| Poly-L-lysine | Synthetic Polyamino Acid Coating | Positively charged polymer (L-isomer); promotes non-specific electrostatic cell adhesion. | Very inexpensive, stable, and easy to use for a wide range of cell types. | Non-specific adhesion lacks biological signaling; can be degraded by cellular proteases; may be cytotoxic at high concentrations. | Routine culture of non-fastidious cells, transient transfections, coating glass slides for histology. | For a cost-effective, simple, and general-purpose coating when specific cell-matrix interaction is not required. |
| Poly-D-lysine | Synthetic Polyamino Acid Coating | Positively charged polymer (D-isomer); promotes non-specific electrostatic cell adhesion. | Resistant to enzymatic degradation by cellular proteases, providing a more stable surface than PLL. | Slightly more expensive than PLL; non-specific adhesion mechanism lacks biological context. | Long-term cultures, primary neuron culture, culturing cells that secrete proteases. | When substrate stability is critical, especially for long-term neuronal cultures sensitive to protease activity. |
| Fibronectin | Extracellular Matrix (ECM) Protein | Glycoprotein that facilitates cell adhesion via specific binding to integrin receptors. | Provides a biologically relevant adhesion mechanism that promotes cell signaling, spreading, and migration. | More expensive and less stable than poly-lysine; requires more careful handling. | Culture of fibroblasts, endothelial cells, and other mesenchymal cells; studies on cell adhesion and signaling. | To mimic a physiological environment and promote specific, integrin-mediated cell-matrix interactions. |
| Laminin | Extracellular Matrix (ECM) Protein | Major protein of the basal lamina; binds to integrins and other cell surface receptors. | Essential for adhesion, differentiation, and migration of specific cell types like neurons and epithelial cells. | Expensive, can have lot-to-lot variability, requires careful storage and handling. | Primary neuronal culture (promotes neurite outgrowth), stem cell culture and differentiation, epithelial cell polarization. | For specialized applications requiring a basement membrane component, particularly for neuronal and stem cell culture. |
| Collagen Type I | Extracellular Matrix (ECM) Protein | Major structural protein in connective tissues; forms a fibrillar matrix for cell attachment. | Relatively inexpensive for an ECM protein; versatile for 2D coatings or 3D gels; supports a broad range of cell types. | Typically animal-derived, leading to potential batch variability; preparation can be more complex than poly-lysine. | Culture of epithelial, endothelial, muscle cells, and fibroblasts; creating 3D culture models and tissue engineering scaffolds. | For a versatile, biologically relevant substrate that supports strong attachment for many common cell lines. |
| Matrigel Basement Membrane Matrix | Solubilized Basement Membrane Extract | A mixture of ECM proteins (laminin, collagen IV) and growth factors; forms a gel at 37°C. | Provides a complex, in vivo-like microenvironment; supports growth of very fastidious cells and 3D structures. | Undefined composition, high lot-to-lot variability, expensive, thermolabile (must be handled on ice). | Stem cell culture and differentiation, organoid and tumor spheroid formation, angiogenesis assays. | When a complex, 3D basement membrane-like environment is essential for cell behavior, differentiation, or morphogenesis. |
Technical Documents
Certificate of Analysis (COA)
Quality assurance documentation
Technical Data Sheet
Detailed technical specifications