Adsorption of the bacteriocins produced by Lactobacillus curvatus CRL705 on a multilayer-LLDPE film for food-packaging applications

Adsorption of bacteriocins produced by Lactobacillus curvatus CRL705, lactocin 705 (whose activity depends upon complementation of two peptides, lac705α and lac705β) and bacteriocin/s with strong anti-Listeria activity, on a multilayer film was investigated. Lactocin 705 adsorption equilibrium at 30 °C was reached from 1 h of film contact. This bacteriocin exhibited a Langmuir-type adsorption, showing a mass adsorption maximum of 0.72 ± 0.05 μg cm−2 and a minimum inhibition concentration of 1 μg ml−1. The influence of impurities, generated from bacteriocinogenic strains growth, on bacteriocins adsorption to the film was investigated by inhibition area evaluation in semisolid agar. Impurities from LAB growth strongly influenced adsorption and lactocin 705 antimicrobial activity on the film, while antilisterial bacteriocin/s adsorption remained unaffected. To explain these results, a lack of lac705β and lac705α peptides complementation necessary for antimicrobial activity, while no interactions among impurities and antilisterial bacteriocin/s during adsorption was suggested. Antilisterial bacteriocin/s activity on the film was not influenced by lactocin 705 adsorption; conformational reorganization of adsorbed antilisterial bacteriocin/s in the presence of lactocin 705 could allow the adsorption of both bacteriocins while maintaining antilisterial antimicrobial activity. This study highlights the technological importance of adsorption optimization to obtain effective antimicrobial food packaging systems.

► Lactocin 705 and AB were adsorbed to a film to obtain a food packaging system. ► Lactocin 705 adsorption equilibrium at 30 °C was reached from 1 h of film contact. ► Impurities generated from bacterium growth worsen lactocin 705 adsorption behavior. ► AB adsorption remained steady despite impurities and lactocin 705 presence. ► We suggested a model to explain adsorption of lactocin 705, AB and impurities.