Resistance of microorganisms to antibiotics has increased. The use of natural components with antimicrobial properties can be of great significance to reduce this problem. The presented work is focused on the study of the effect of encapsulation of selected plant and animal antimicrobial substances (herbs, spices, lysozyme and nisin) on their activity and stability. Antimicrobial components were packaged into liposomes and polysaccharide particles (alginate, chitosan and starch). Antimicrobial activity was tested against two Gram-positive (Bacillus subtilis and Micrococcus luteus) and two Gram-negative (Escherichia coli and Serratia marcescens) bacteria. Encapsulation was successful in all types of polysaccharide particles and liposomes. The prepared particles exhibited very good long-term stability, especially in aqueous conditions. Antimicrobial activity was retained in all types of particles. Liposomes with encapsulated herb and spice extracts exhibited very good inhibitory effect against all tested bacterial strains. Most of herbal extracts had very good antimicrobial effect against the tested Gram-negative bacterial strains, while Gram-positive bacteria were more sensitive to lysozyme particles. Thus, particles with co-encapsulated herbs and lysozyme are more active against different types of bacteria, and more stable and more effective during long-term storage. Particles with encapsulated mixture of selected plant extracts and lysozyme could be used as complex antimicrobial preparation with controlled release in the production of food and food supplements, pharmaceutical and cosmetic industries.

The aim of this study was to evaluate the influence of model (alcohol, sugar, salt, protein and acid) and real foods and beverages on the viability of probiotics during incubation and artificial digestion. Viability of monocultures Lactobacillus acidophilus CCM4833 and Bifidobacterium breve CCM7825T, and a commercial mixture of 9 probiotic bacterial strains, was tested by cultivation assay and flow cytometry. In model foods, the best viability was determined in the presence of 0.2 g/L glucose, 10% albumin and 10% ethanol. As the most suitable real food for probiotic survival, complex protein and carbohydrate substrates were found, such as beef broth, potato salad with pork, chicken with rice, chocolate spread, porridge and yoghurt. The best liquid was milk and meat broth, followed by Coca-Cola, beer and coffee. Viability of probiotics was higher when consumed with meals than with beverages only. Addition of prebiotics increased the viability of probiotics, especially in presence of instant and fast foods. Generally, the highest viability of probiotics during artificial digestion was observed in mixed culture in the presence of protein, sugar and fat, or their combination. The increase of cell viability observed in such foods during model digestion may further contribute to the positive effect of probiotics on human health.

Polyoxazolines are a new promising class of polymers for biomedical applications. Antibiofouling polyoxazoline coatings can suppress bacterial colonization of medical devices, which can cause infections to patients. However, the creation of oxazoline-based films using conventional methods is difficult. This study presents a new way to produce plasma polymerized oxazoline-based films with antibiofouling properties and good biocompatibility. The films were created via plasma deposition from 2-methyl-2-oxazoline vapors in nitrogen atmospheric pressure dielectric barrier discharge. Diverse film properties were achieved by increasing the substrate temperature at the deposition. The physical and chemical properties of plasma polymerized polyoxazoline films were studied by SEM, EDX, FTIR, AFM, depth-sensing indentation technique, and surface energy measurement. After tuning of the deposition parameters, films with a capacity to resist bacterial biofilm formation were achieved. Deposited films also promote cell viability.