E-Polylysine and Nisin are both natural antimicrobial peptides widely used as food preservatives. However, they have significant differences in their structure, antimicrobial spectrum, stability, and applications. Below is a professional, research-based comparison to help businesses and manufacturers understand when to choose E-Polylysine over Nisin and vice versa.

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1. Source & Production Process

Feature	E-Polylysine	Nisin
Produced by	Streptomyces albulus (a soil-based bacteria)	Lactococcus lactis (a lactic acid bacterium)
Fermentation Type	Alkaline fermentation	Acidic fermentation
Extraction Process	Purified from bacterial culture	Extracted from dairy fermentation

• Key Difference:
  • E-Polylysine is derived from Streptomyces bacteria, whereas Nisin originates from lactic acid bacteria.
  • E-Polylysine is produced in an alkaline environment, whereas Nisin is produced in acidic conditions.

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2. Chemical Structure & Mechanism of Action

Feature	E-Polylysine	Nisin
Chemical Type	Homopolymer of L-Lysine (a chain of amino acids)	Peptide composed of 34 amino acids
Molecular Weight	~4,000 – 5,000 Da	~3,500 Da
Charge	Strongly cationic (positively charged)	Less cationic than E-Polylysine
Mode of Action	Disrupts bacterial cell membranes, leading to cell death	Binds to lipid II, preventing bacterial cell wall synthesis
Solubility	Water-soluble, stable in acidic & neutral pH	Acid-soluble, less stable at neutral pH

• Key Difference:
  • E-Polylysine acts by disrupting bacterial membranes, making it effective against Gram-positive & some Gram-negative bacteria.
  • Nisin targets bacterial cell wall synthesis, making it mainly effective against Gram-positive bacteria (not Gram-negative).

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3. Antimicrobial Spectrum & Stability

Feature	E-Polylysine	Nisin
Effective Against	Gram-positive & Gram-negative bacteria, molds, yeasts	Mostly Gram-positive bacteria
Heat Stability	Highly stable (withstands 120°C for 30 min)	Moderate stability (degrades above 100°C)
pH Stability	Effective from pH 2.5 – 9.0	Effective from pH 2.5 – 6.5
Synergistic Effects	Works well with Nisin, organic acids, chitosan	Works well with E-Polylysine, EDTA, essential oils

• Key Difference:
  • E-Polylysine has a broader antimicrobial spectrum, working against both Gram-positive & some Gram-negative bacteria, yeasts, and molds.
  • Nisin is more specific to Gram-positive bacteria, making it effective in dairy and meat applications where Gram-positive pathogens like Listeria and Clostridium are a concern.
  • E-Polylysine is more heat-stable and works in a broader pH range, making it better for high-temperature processing.

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4. Applications & Best Uses

Feature	E-Polylysine	Nisin
Best for	High-fat, high-protein foods, emulsions, bakery, beverages	Dairy, meats, low-pH foods, canned foods
Dairy	Less commonly used	Very effective (cheese, milk, yogurt)
Meat & Poultry	Suitable for meat & plant-based meat	Best for meat and poultry preservation
Beverages	Used in juices, soft drinks	Less effective in neutral pH beverages
Bakery	Prevents mold in bread and cakes	Less effective
Plant-Based Foods	Used in plant-based dairy and meat	Limited use in plant-based applications

• Key Difference:
  • Nisin is best for dairy & meat applications, as it is highly effective against Listeria and Clostridium botulinum.
  • E-Polylysine is better for processed foods, plant-based products, and beverages, as it works well in neutral and slightly alkaline conditions.

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5. Regulatory Approvals & Safety

Feature	E-Polylysine	Nisin
GRAS (Generally Recognized as Safe)?	✅ Yes	✅ Yes
E-Number (EU Approved)?	E239	E234
Approved by FDA, EFSA, WHO?	✅ Yes	✅ Yes
Allergen-Free?	✅ Yes	❌ No (dairy-based origin)
Vegan-Friendly?	✅ Yes	❌ No

• Key Difference:
  • E-Polylysine is suitable for vegan and allergen-free formulations, making it a great choice for plant-based and dairy-free products.
  • Nisin is derived from dairy fermentation, which may not be suitable for some vegan or dairy-free formulations.

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6. Cost & Economic Considerations

Feature	E-Polylysine	Nisin
Production Cost	Higher due to polymer complexity	Lower due to simpler peptide synthesis
Usage Level	10 – 15 ppm	5 – 25 ppm
Shelf Life	2 years	2 years

• Key Difference:
  • E-Polylysine is generally more expensive than Nisin but requires lower doses in certain applications.
  • Nisin is cost-effective for dairy & meat industries but has limitations in neutral/alkaline foods.

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Which One Should You Choose?

✅ Choose E-Polylysine if:

✔ You need broad-spectrum antimicrobial activity, including against Gram-negative bacteria, yeasts, and molds.
✔ Your product is neutral or slightly alkaline (pH 6.5 – 9.0), such as bakery, plant-based foods, and beverages.
✔ You require vegan, allergen-free, and dairy-free preservation.
✔ Your product undergoes high-temperature processing (above 100°C).

✅ Choose Nisin if:

✔ Your main concern is Gram-positive pathogens like Listeria and Clostridium.
✔ Your product is acidic (pH 2.5 – 6.5), such as dairy, meat, and canned foods.
✔ You need a cost-effective preservative for meat, cheese, and dairy applications.

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Conclusion: E-Polylysine vs. Nisin – Which is Better?

• E-Polylysine is more versatile, working in a wider pH range and targeting more types of microbes.
• Nisin is highly effective against Gram-positive bacteria, making it the gold standard in dairy and meat preservation.
• For best results, they can be used together, offering synergistic antimicrobial effects to enhance food safety.

At Chibio Biotech, we offer high-quality E-Polylysine and Nisin for food, pharmaceutical, and cosmetic applications.

📩 Contact us now at sales@chibiotech.com for bulk inquiries and customized solutions!