Due to the emergence of nanoscience and technology, metallic silver nanoparticles (AgNPs) are used as antimicrobial agents and are synthesized following various protocols. Several methods (Physical and Chemical) are used to synthesize nanoparticles, but biological methods are preferred due to their environmental friendliness, cleanliness, safety, cost-effectiveness, ease and efficiency for high productivity and purity. Green synthesis of nanoparticles (NPs) is a promising new tool in the field of bio-nanotechnology. Intra- or extracellular biosynthesis of NPs can be achieved by a wide range of biological entities, including bacteria, fungi, yeast, algae, actinomycetes and plant extracts. Biosynthesized NPs are characterized using a variety of techniques, including UV-vis spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), and Fourier transform infrared (FTIR) analysis and zeta potential analyses. NPs synthesized using the green approach can be used in the food industry, smart agriculture and wastewater treatment. They can be incorporated into various biotechnological fields as antimicrobial agents, antioxidants and phytopathogen control agents. This review will focus on the role of biosynthesized AgNPs for their antimicrobial application, leading to improved health, environment and prevention of infectious diseases.

Fish is a very perishable foodstuff whose preservation requires a continuous cold chain. The study aims to evaluate the effect of the break in cold chain on the bacteriological quality of Scomber scombrus (Atlantic mackerel) and Trachurus trachurus (Horse mackerel). Thus, data were collected from June to December 2016 in South Benin. A total of 120 fish were divided in control (cold chain integrity) and experimental (3h, 6h and 12h of break in cold chain) batches in order to determine the microorganism loads by cold chain break duration. Total Mesophilic Aerobic Flora (TMAF) and Clostridium perfringens loads were significantly higher in chilled fish samples than in frozen fish (p<0.001). However, no significant difference was observed between the control and the experimental batches whatever the preservation method and the cold chain break duration (p>0.05) for the TMAF. No Clostridium perfringens was counted for the freezing. Similarly, Staphylococcus aureus were not counted, except in the refrigerated batch for 3 hours of cold chain break. The TMAF and Clostridium perfringens loads increased according to cold chain break duration. For the FMAT, the highest load was observed at 12 hours of break in cold chain. In the majority of cases, Enterobacterium load was higher in the experimental batches compared to control batches. No samples revealed the presence of total coliforms, fecal coliforms, Salmonella and Escherichia coli. The rigorous cold chain keeping throughout the preservation until consumption significantly prevents the proliferation of fish contamination flora.