Titanium dioxide nanoparticles fabrication from Parmotrema austrosinense (Zahlbr.) Hale extracts and its antimicrobial efficacy against plant pathogens

Green chemistry adoption in biosynthesis of nanoparticles has revolutionized the realm of phyto-medicine. Lichens that comprise the symbiotic association of fungi and either algae or cyanobacteria render eco-friendly and biocompatible applications. A plethora of secondary metabolites with redox potentials from lichens have wide applications as bioactive incumbents and bio-indicators of pollution. The present study reports, the synthesis of titanium dioxide nanoparticles (TiO2-NPs) using an ultra-sonicated aqueous extract of the lichen Parmotrema austrosinense (Zahlbr.) Hale. The physico-chemical properties of TiO2-NPs were characterized using UV–Visible spectroscopy, Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and Scanning electron microscopic (SEM) techniques. Bio-synthesized TiO2-NPs exhibited an average particle size of 10–80 nm indicating structural variability. Phytochemical properties were estimated prior to assessment of antibacterial efficacies elicited by the synthesized by testing it against selected bacterial and fungal plant pathogens such as Bacillus subtilis, Erwinia chrysanthemi, Xanthomonas phaseoli, Fusarium oxysporum, Rhizoctonia solani, and Sclerotium rolfsii respectively using agar well diffusion method. The results revealed that as prepared TiO2 nanoparticles from lichens owned significant antimicrobial activity against X. phaseoli and F. oxysporum.