Strong and nonspecific synergistic antibacterial/antibiofilm impact of nano-silver biosynthesized and decorated with active ingredients of Oscimum basilicum L

Green Synthesis of Silver Nanoparticles Using Ocimum basilicum L. and Hibiscus sabdariffa L. Extracts and Their Antibacterial Activity in Combination with Phage ZCSE6 and Sensing Properties

One of the dangerous pathogens that display high resistance to antibiotics is Salmonella enterica (S. enterica), which infects humans and animals. In this study, a new approach was proposed to fight antibiotic-resistant bacteria by using silver nanoparticles (AgNPs) with adding the phage ZCSE6. The biosynthesized AgNPs were characterized by analysis of spectroscopy profile of the UV–Vis, visualize the morphology, and size with transmission electron microscopy. Both minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were assessed. In addition, the AgNPs were able to control the biofilm formation of S. enterica, also, heavy metals detection by AgNPs and their application in milk. UV–Vis spectra showed a surface resonance peak of 400 and 430 nm corresponding to the formation of AgNPs capping with Ocimum basilicum L. and Hibiscus sabdariffa L., respectively. The MIC and MBC values were 6.25 µg/ml to inhibit the growth of S. enterica and 12.5 µg/ml from killing the bacteria and it was decreased to 1.5 µg/ml when combined with the phage. In the present study, AgNPs were combined with phage ZCSE6 to obtain a synergetic antimicrobial activity. Moreover, it increases the milk’s shelf-life and senses the Cd2+ at a concentration of 1 mM in the water.

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Essential Oil Nanoemulsion as Eco-Friendly and Safe Preservative: Bioefficacy Against Microbial Food Deterioration and Toxin Secretion, Mode of Action, and Future Opportunities

Microbes are the biggest shareholder for the quantitative and qualitative deterioration of food commodities at different stages of production, transportation, and storage, along with the secretion of toxic secondary metabolites. Indiscriminate application of synthetic preservatives may develop resistance in microbial strains and associated complications in human health with broad-spectrum environmental non-sustainability. The application of essential oils (EOs) as a natural antimicrobial and their efficacy for the preservation of foods has been of present interest and growing consumer demand in the current generation. However, the loss in bioactivity of EOs from fluctuating environmental conditions is a major limitation during their practical application, which could be overcome by encapsulating them in a suitable biodegradable and biocompatible polymer matrix with enhancement to their efficacy and stability. Among different nanoencapsulated systems, nanoemulsions effectively contribute to the practical applications of EOs by expanding their dispersibility and foster their controlled delivery in food systems. In line with the above background, this review aims to present the practical application of nanoemulsions (a) by addressing their direct and indirect (EO nanoemulsion coating leading to active packaging) consistent support in a real food system, (b) biochemical actions related to antimicrobial mechanisms, (c) effectiveness of nanoemulsion as bio-nanosensor with large scale practical applicability, (d) critical evaluation of toxicity, safety, and regulatory issues, and (e) market demand of nanoemulsion in pharmaceuticals and nutraceuticals along with the current challenges and future opportunities.