One-pot synthesis of magnetic self-assembled carrageenan-ε-polylysine composites: A reusable and effective antibacterial agent against Alicyclobacillus acidoterrestris

Epsilon-polylysine (EPL) is a cationic polymer with broad antibacterial activity. Base on this property, anionic carrageenan (CG) was self-assembled with EPL and introduced into the one-pot coprecipitation process to fabricate the magnetic Fe 3 O 4 -CG-EPL composites. To demonstrate the successful synthesis of composites, characterization techniques including XRD, FT-IR, TEM, XPS and VSM were employed. The prepared composites exhibited effective antibacterial activity against Alicyclobacillus acidoterrestris with the minimum inhibitory concentration of 10.0 mg mL −1 . Investigations into deciphering the antibacterial mechanism demonstrated that the presence of Fe 3 O 4 -CG-EPL caused irreversible damage to the cell membrane and serious leakage of intracellular protein, resulting in the inactivation of bacteria. The aim of this work is to develop a new effective control method for A. acidoterrestris in food field.