Chemical Characterization of Honey and Its Effect (Alone as well as with Synthesized Silver Nanoparticles) on Microbial Pathogens' and Human Cancer Cell Lines' Growth.

The antibacterial, anticancer, and wound-healing effects of honey can vary according to the type, geographical region, honey bee species, and source of the flowers. Nanotechnology is an innovative and emerging field of science with an enormous potential role in medical, cosmetics, and industrial usages globally. Metal nanoparticles that derived from silver and range between 1 nm and 100 nm in size are called silver nanoparticles (AgNPs). Much advanced research AgNPs has been conducted due to their potential antibacterial and anticancer activity, chemical stability, and ease of synthesis. The purpose of the present study was to explore the physicochemical properties of honey and the potential to use forest honey to synthesize AgNPs as well as to appraise the nanoparticles' antimicrobial and anticancer effects. Here, we used three different percentages of forest honey (20%, 40%, and 80%) as biogenic mediators to synthesize AgNPs at room temperature. The development of AgNPs was confirmed by color change (to the naked eye) and ultraviolet-visible spectroscopy studies, respectively. The absorbance peak obtained between 464 to 4720 nm validated both the surface plasmon resonance (SPR) band and the formation of AgNPs. Regarding the sugar profile, the contents of maltose and glucose were lower than the content of fructose. In addition, the results showed that the SPR band of AgNPs increased as the percentage of forest honey increased due to the elevation of the concentration of the bio-reducing agent. A bacterial growth kinetic assay indicated the strong antibacterial efficacy of honey with silver nanoparticles against each tested bacterial strain. Honey with nanotherapy was the most effective against hepatocellular carcinoma (HepG2) and colon cancer (HCT 116) cells, with IC50s of 23.9 and 27.4 µg/mL, respectively, while being less effective against breast adenocarcinoma cells (MCF-7), with an IC50 of 32.5 µg/mL.

Klebsiella oxytoca: an efficient pyrene-degrading bacterial strain isolated from petroleum-contaminated soil.

Polycyclic aromatic hydrocarbons (PAHs) are the hazardous xenobiotic agents of oil production. One of the methods to eliminate hazardous compounds is bioremediation, which is the most efficient and cost-effective method to eliminate the harmful byproducts of crude petroleum processing. In this study, five pure bacterial isolates were isolated from petroleum-contaminated soil, four of which showed a robust growth on the PAH pyrene, as a sole carbon source. Various methods viz mass spectroscopy, biochemical assays, and 16S RNA sequencing employed to identify the isolates ascertained the consistent identification of Klebsiella oxytoca by all three methods. Scanning electron microscopy and Gram staining further demonstrated the characterization of the K. oxytoca. High-performance liquid chromatography of the culture supernatant of K. oxytoca grown in pyrene containing media showed that the cells started utilizing pyrene from the 6th day onwards and by the 12th day of growth, 70% of the pyrene was completely degraded. A genome search for the genes predicted to be involved in pyrene degradation using Kyoto Encyclopedia of Genes and Genomes (KEGG) confirmed their presence in the genome of K. oxytoca. These results suggest that K. oxytoca would be a suitable candidate for removing soil aromatic hydrocarbons.

Bioplastic (poly-3-hydroxybutyrate) production by the marine bacterium Pseudodonghicola xiamenensis through date syrup valorization and structural assessment of the biopolymer.

Biobased degradable plastics have received significant attention owing to their potential application as a green alternative to synthetic plastics. A dye-based procedure was used to screen poly-3-hydroxybutyrate (PHB)-producing marine bacteria isolated from the Red Sea, Saudi Arabia. Among the 56 bacterial isolates, Pseudodonghicola xiamenensis, identified using 16S rRNA gene analyses, accumulated the highest amount of PHB. The highest PHB production by P. xiamenensis was achieved after 96 h of incubation at pH 7.5 and 35 °C in the presence of 4% NaCl, and peptone was the preferred nitrogen source. The use of date syrup at 4% (w/v) resulted in a PHB concentration of 15.54 g/L and a PHB yield of 38.85% of the date syrup, with a productivity rate of 0.162 g/L/h, which could substantially improve the production cost. Structural assessment of the bioplastic by Fourier transform infrared spectroscopy and nuclear magnetic resonance spectroscopy revealed the presence of methyl, hydroxyl, methine, methylene, and ester carbonyl groups in the extracted polymer. The derivative products of butanoic acid estimated by gas chromatography-mass spectrometry [butanoic acid, 2-amino-4-(methylseleno), hexanoic acid, 4-methyl-, methyl ester, and hexanedioic acid, monomethyl ester] confirmed the structure of PHB. The present results are the first report on the production of a bioplastic by P. xiamenensis, suggesting that Red Sea habitats are a potential biological reservoir for novel bioplastic-producing bacteria.