Epsilon Polylysine Introduction
Epsilon Polylysine is a naturally produced, cationic homopolymer of 25-30 L-lysine（due to Streptomyces albulus fermentation.), which was connected by ε-amido bond compounded by a e-amido of l-lysine and a e-carboxyl of another l-lysine.
◆Various functions: Polylysine molecules are cationic, surface active agents in water due to their positively charged amino groups. This property imports many benefits when used as an ingredient in cosmetics.
◆Easy to use: readily soluble in water, highly heat-stable and useable over a wide pH range (5-8).
Physical and Chemical Properties
Appearance and Physical State: milky yellow to white
Form at 20°C：powder
Melting Point: 172.8 °C
Solubility in Water: soluble
molecular formula：C6H12n+2N2On+1 (n＝25～30)；
molecular weight：3600～4300 DA
Table 1 ε-PL MIC (minimum inhibition concentration) Test
Different Types of Microorganisms
Aspergillus niger IFO4416
Trichophyton mentagrophytes IFO7522
Candida acutus IFO1912
Phaffia rhodozyma IFO10129
Pichia anomala IFO0146
Pichia membranaefaciens IFO0577
Rhodotorula lactase IFO1423
Sporobolomyces roseus IFO1037
Zygosaccharomyces rouxii IFO1130
Geobacillus stearothermophilus IFO12550
Bacillus coagulans IFO12583
Bacillus subtilis IAM1069
Clostridium acetobutylicum IFO13948
Lactobacillus brevis IFO3960
L1 plantarum IFO12519
Micrococcus luteus IFO12708
Staphylococcus aureus IFO13276
Streptococcus lactis IFO12546
Raoultella planticola IFO3317
Escherichia coli IFO13500
Pseudomonas aeruginosa IFO3923
As can be seen, ε-PL has wide range of antimicrobial spectrum with minimum inhibitory concentration of bacteria less than 100μg/ml, and to Fungi, the MIC is higher.
Table-2 Effect of temperature on the Minimum Inhibition Concentration (MIC) of ε-Polylysine against Growth of Escherichia coil
Table 3 PH on ε-PL MIC
Ε-PL can effectively inhibit the growth of undesirable microorganisms in foods, such as bakery food( bread , cake etc.), beverage( soybean milk, fruit beverage) and meat products.