Effective inhibition of waterborne and fungal pathogens using ZnO nanoparticles prepared from an aqueous extract of propolis: optimum biosynthesis, characterization, and antimicrobial activity

The increased pollution caused by Yemen’s civil war prompted researchers to be more creative in reducing pollution, even with the use of simple methods. This research aims to present an alternative, simple solution to the problem of water pollution and some diseases through the biological preparation of zinc oxide nanoparticles using propolis aqueous extract. The volume ratio of the reactants, pH, temperature, and contact time were evaluated as factors influencing the biosynthesis of ZnO nanoparticles. The size of these nanoparticles ranged between 12.78 nm and 54.95 nm, and their shape was approximately hexagonal. These results were confirmed by transmission electron microscopy (TEM) and X-ray diffraction. The antimicrobial activity of optimally prepared ZnO nanoparticles was studied using different strains of microbes, Gram-positive bacteria (Bacillus Subtilis and Staph. Aureus), Gram-negative bacteria (Escherichia Coli and Pseudomonas Aeruginosa), and fungal microorganisms (Candida Albicans and Mucor). The nanoparticles were found to be more effective than gentamicin (an antibiotic) at inhibiting waterborne and some fungal pathogens. The current study also revealed more effective and promising results when compared to earlier studies on the antibacterial activity of other manufactured nanoparticles.