Development of Biodegradable Films Loaded with Phages with Antilisterial Properties

Abstract

The inhibitory and bactericidal capacity of Listex P100 bacteriophage has been studied against different concentrations of Listeria monocytogenes in stationary and exponential phases. Three different matrices were employed to developed films incorporating Listex P100: (1) sodium caseinate, (2) sodium alginate mixed with gelatin, and (3) polyvinyl alcohol (PVOH). All the films were successfully developed by casting at room temperature. These active biodegradable films were optical, structural, and thermally characterized, and their antimicrobial capacities against L. monocytogenes were studied. The incorporation of phages did not affect the morphology, colour, opacity, and thermal stability of polymers. The antimicrobial analysis revealed the bacteriophage presented a high antimicrobial capacity against L. monocytogenes in the stationary phase (4.40 and 6.19 log reduction values or bactericide effect depending on the initial inoculum of the pathogen). Developed films showed antimicrobial capacity close to 1 log after 24 h of incubation at 30 °C. The effectiveness of PVOH films was greater under refrigeration conditions, reaching 2 log reduction after eight days of incubation. The use of these films as a coating in a food or as part of a packaging could improve food safety against the growth of pathogenic microorganisms such as Listeria monocytogenes.

Electrostatic Assembly of Anti-Listeria Bacteriophages on a Self-Assembled Monolayer of Aminoundecanethiol: Film Morphology and Charge Transfer Studies

“…Although the characteristic shape of HVs (Scheme 1A) could not be resolved in our microscopic images, it can be concluded that the largest fraction of the particles spotted in Figs 3C, 3F, 4A, 4D, and 6A correspond to isolated P100 phages immobilized on Au/AUT. This is supported by the dimensions reported in the literature for isolated active HVs (200-300 nm [37][38][39]), which are consistent with the measurements from our AFM/SEM data, but also by the perfect match between the shape and size of the particles found in our images and those reported for the mica/PEI/T4 slides prepared by Szermer-Olearnik et al [36].…”

Novel Bacteriophage-Based Food Packaging: An Innovative Food Safety Approach

“…Bacteriophages are excellent for preventing or reducing animal illnesses (phage treatment), disinfecting raw materials and carcasses, such as fresh vegetables and fruit, cleaning equipment, and rigid contact interfaces [39]. Using phages in place of antibiotics in agricultural practices is a viable alternative to preserve animal and plant health and reduce the spread of AMR and zoonotic diseases that can be dangerous to consumers [39,40].…”

Natural Antimicrobials as Additives for Edible Food Packaging Applications: A Review

“…It was demonstrated that bacteriophage had a strong antibacterial potential against L. monocytogenes with 4.40 and 6.19 log reduction values. To extend bacteriophages to packaging systems, current research has investigated means of maintaining phage stability and activity [33]. Kalkan [34] tested the effectiveness of encapsulated bacteriophages in methylcellulose edible films against Vibrioparahaemolyticus ATCC 17802 in raw fish fillets.…”