Natural cationic polymer ε-Polylysine

FEATURES

Features of ε-Polylysine

Functions of ε-Polylysine

ε-Polylysine, a cationic polymer, has various functions such as:

Antimicrobial effect of ε-Polylysine

Antimicrobial effect that suppresses the growth of microorganisms

ε-Polylysine has a growth inhibitory effect on various microorganisms.
The anrimicrobial mechanism of ε-Polylysine is that the electrostatic interaction between the cationic site of ε-Polylysine and the anionic site on the surface of the cell membrane of microorganisms damages the cell membrane and inhibits growth.
Due to such a simple mechanism, it exhibits growth inhibitory effects on various microorganisms (Gram-positive bacteria, Gram-negative bacteria, yeast, fungi, etc.).

Minimum inhibitory concentration (MIC) for various microorganisms

Microorganism Minimum inhibitory concentration
mg/L
Lactobacillus brevis 10
Lactococcus lactis 100
Escherichia coli ( NBRC 13500) 50
Staphylococcus aureus 12
Pseudomonas aeruginosa < 3
Salmonella enterica subsp. enterica 16
Bacillus subtilis 3
Bacillus cereus 50
Geobacillus stearothermophilus 5
Micrococccus luteus 16
Clostridium sporogenes 32
Campylobacter jejuni 100
Saccharomyces cerevisiae 50
Candida albicans 250
Candida utilis < 3
Pichia membranifaciens < 3
Wickerhamomyces anomalus 150
Zygosaccharomyces rouxii 150
Rhodotorula lactosa 25
Aspergillus brasiliensis 250
Malassezia furfur 16

ε-Polylysine exhibits antimicrobial effect over a wide pH range

ε-Polylysine has a lower minimum inhibitory concentration (MIC) and exhibits excellent antimicrobial activity over a wide pH range when compared to existing raw materials with antimicrobial activity. Therefore, it is possible to improve the shelf life without spoiling the flavor of the food.

MIC (mg/L) of various antibacterial agents against E. coli at each pH

Classification Antimicrobial agent pH
5 6 7 8 9
Preservative ε-Polylysine 25 25 50 50 200
Sorbic acid 8,700 13,400 15,000 25,000 -
Shelf life improver Acetic acid 15,000 35,000 35,000 60,000 -
Glycine 35,000 20,000 15,000 10,000 10,000

Excellent bacteriostasis even when heated

ε-Polylysine does not easily lose its antimicrobial properties even when heated. The antimicrobial property was maintained even after heating at 120°C for 20 minutes. Therefore, it can be used as an additive to food and in a wide range of applications for other industrial agents.

Minimum inhibitory concentration (MIC) against E. Coli (NBRC13500)

Heating conditions Minimum inhibitory concentration（mg/L）
No heating 50
80℃, 60 minutes 50
100℃, 30 minutes 50
120℃, 20 minutes 50

ε-Polylysine exhibits excellent bactericidal effect

Ingredients such as acetic acid that improve shelf life have a bacteriostatic effect, but ε-Polylysine can be expected to have a bactericidal effect. When ε-Polylysine is used in combination with ingredients that improve shelf life, such as acetic acid, it is expected that the expiration date will be extended due to the synergistic effect.

ε-Polylysine aggregates proteins etc.

ε-Polylysine has the effect of aggregating and precipitating bacterial cell, proteins, nucleic acids, polysaccharides, etc.
Due to the interaction between the cation site of ε-Polylysine and the anion site of bacterial cell, etc., it exhibits strong agglutinating properties.

Aggregation / precipitation effect of bacteria

Aggregation / precipitation effect of xanthan gum

Adsorption effect as scaffold material for cells

ε-Polylysine has the effect of adsorbing cells. Due to its extremely low toxicity, various cells can be stably established.
ε-Polylysine showed better cell adhesion effect than α-Polylysine in HeLa D98 cell culture.

  • Uncoated

  • α-Polylysine

  • ε-Polylysine

Adsorption of ε-Polylysine to horny cell layer and hair

ε-Polylysine has the effect of adsorbing to hair and stratum corneum. Hair treated with ε-Polylysine showed improved combability and cuticle protection. You can expect the effect of ε-Polylysine to improve hair quality.

Adsorption of fluorescently labeled ε-Polylysine to human stratum corneum

  • 0 μg/mL

  • 10 μg/mL

  • 30 μg/mL

  • 100 μg/mL

  • Fluorescence intensity increased depending on ε-Polylysine concentration

Adsorption of fluorescently labeled ε-Polylysine to human horny cell layer

  • 0 μg/mL

  • 1 μg/mL

  • 10 μg/mL

  • 100 μg/mL

  • Fluorescence intensity increased depending on ε-Polylysine concentration

provided from Professor Tetsuji Hirao
in Mukogawa Woman’s University

Deodorizing effect of ε-Polylysine

A deodorizing effect was obtained by adding ε-Polylysine to the malodorous substance. In particular, it exhibits deodorizing effects on lower fatty acids.

Malodorants, ε-Polylysine or pure water were added to F2s bags. It was filled with air, sealed and placed in a warm bath. After standing to cool, the concentration of malodorous substances was measured with a detector tube.

Dispersion effect of ε-Polylysine

Dispersion of nanomaterials by ε-Polylysine

Adding ε-Polylysine improves the dispersibility of carbon black in water. Nanomaterials are known to aggregate due to van der Waals forces. Since ε-Polylysine is a cationic polymer, it can suppress van der Waals forces and allow nanomaterials to be well dispersed.

Appearance immediately after adding carbon black to each concentration of ε-Polylysine aqueous solution.

Stirring after adding carbon black to ε-Polylysine aqueous solution of each concentration.