RESUMEN
Multidrug-resistant strains (MDRs) are becoming a major concern in a variety of settings, including water treatment and the medical industry. Well-dispersed catalysts such as BiPO4, ZnO nanoparticles (NPs), and different ratios of BiPO4/ZnO nanocomposites (NCs) were synthesized through hydrothermal treatments. The morphological behavior of the prepared catalysts was characterized using XRD, Raman spectra, PL, UV-Vis diffuse reflectance spectroscopy (UV-DRS), SEM, EDX, and Fe-SEM. MDRs were isolated and identified by the 16s rDNA technique as belonging to B. flexus, B. filamentosus, P. stutzeri, and A. baumannii. The antibacterial activity against MDRs and the photocatalytic methylene blue (MB) dye degradation activity of the synthesized NPs and NCs were studied. The results demonstrate that the prepared BiPO4/ZnO-NCs (B1Z4-75:300; NCs-4) caused a maximum growth inhibition of 20 mm against A. baumannii and a minimum growth inhibition of 12 mm against B. filamentosus at 80 µg mL-1 concentrations of the NPs and NCs. Thus, NCs-4 might be a suitable alternative to further explore and develop as an antibacterial agent. The obtained results statistically justified the data (p ≤ 0.05) via one-way analysis of variance (ANOVA). According to the results of the antibacterial and photocatalytic study, we selected the best bimetallic NCs-4 for the photoexcited antibacterial effect of MDRs, including Gram ve+ and Gram ve- strains, via UV light irradiation. The flower-like NCs-4 composites showed more effectiveness than those of BiPO4, ZnO, and other ratios of NCs. The results encourage the development of flower-like NCs-4 to enhance the photocatalytic antibacterial technique for water purification.
Asunto(s)
Nanocompuestos , Nanopartículas , Óxido de Zinc , Óxido de Zinc/farmacología , Óxido de Zinc/química , Nanocompuestos/química , Rayos Ultravioleta , Antibacterianos/farmacología , Antibacterianos/químicaRESUMEN
The fatty acid composition of bacterial isolates remains stable under standardized culture conditions, which makes it a useful taxonomic marker. The present study aims to characterize the diversity and quantity of fatty acid methyl esters (FAME) profiles of cultivable bacterial isolates collected along the southwest coast of India. Based on the similarity indices (range > 0.3-0.7) of the FAME profiles, the isolates were aggregated into 10 families, 11 genera and 19 species of cultured isolates. The following classes of bacteria were found: Bacilli, Alphaproteobacteria, Betaproteobacteria, Gammaproteobacteria and Actinobacteria, which also included a few pathogens such as Pseudomonas, Staphylococcus and Bacillus sp. The hydroxyl FAMEs 2-hydroxydodecanoic acid (C12:0 2OH), 2-hydroxypentadecanoic acid (C15:0 2OH),3-hydroxy 14-methylpentadecanoic acid (C16:0iso 3OH), 3 hydroxy hexadecenoic acid (C16:0 3OH) and 3-hydroxy 15-methylhexadecanoic acid (C17:0iso 3OH), as well as the unsaturated FAMEs (11Z)-11-hexadecenoic acid (C16:1 É·5c), were exclusively associated with the isolates from Mangalore samples. Similarly, FAMEs 2-hydroxydecanoic acid (C10:0 2OH), 9-methyldecanoic acid (C11:0iso), undecanoic acid (C11:0), tridecanoic acid (C13:0), 10-methylhexadecanoic acid (C16:0 10-CH3) and (7Z)-7-hexadecenoic acid (C16:1 É·9c) occurred only in the isolates from Trivandrum samples. However, the isolates from Goa did not possess a signature FAME profile. The reproducibility of the GC-MIDI bacterial identification system was evaluated using 16S rRNA gene sequencing techniques for selected isolates.