1984 Volume 37 Issue 11 Pages 1449-1455
The antimicrobial spectrum of ε-poly-L-lysine (n=25-30, ε-PL) was investigated by comparison with α-poly-L-lysine (n=50, α-PL). ε-PL showed antimicrobial activity against Gram-positive and-negative bacteria at concentrations of 1-8μg/ml. α-PL was less active than ε-PL A chain length of at least 10 L-lysine monomers was found to be optimum for antimicrobial activity. Chemical modification of the amino groups of ε-PL lowered its antibacterial activity. Studies on the mode of action of ε-PL suggest that adsorption of ε-PL to the bacterial cell surface plays an important role in its antibacterial activity.