Green biogenic synthesis of zinc oxide nanoparticles using Pseudomonas putida culture and its In vitro antibacterial and anti-biofilm activity

In the present work we demonstrated an environmentally acceptable biogenic synthesis of ZnO NPs using Pseudomonas putida (MCC 2989) broth culture. The physiochemical and morphological characters of the synthesized ZnO NPs was confirmed using UV-vis spectroscopy, XRD, SEM-EDX, and FTIR. The anti biofilm and anti bacterial activity of the synthesized ZnO NPs were studied against Pseudomonas otitidis (MCC 2509), Pseudomonas oleovorans (MCC 2566), Acinetobacter baumannii (MCC 2366), Bacillus cereus (MCC, 2039), and Enterococcus faecalis (MCC, 2041) using MTP and disk diffusion assay. The UV-Vis spectra show maximum absorbance of 300 and 310 nm for supernatant and isolated ZnO pellet, respectively, with a corresponding band gap of 4.00 eV. The FTIR results show the evidence for the presence of C=O, CH, and NH2 groups, which proves the presence of remains of carbohydrates and amino acids from the bacterial culture used that is responsible for the formation of nanoparticle as well as for its stabilization. The results of anti-biofilm activity by MEP assay proved that the green synthesized ZnO NPs showed very potent activity against the tested microbial biofilms. Further, the ZnO NPs possess great anti microbial activity against the tested gram (+) and gram (-) ve microbes.