Biosynthesis of titanium dioxide nanoparticles using probiotic bacterial strain, Lactobacillus rhamnosus, and evaluate of their biocompatibility and antifungal activity

Abstract

Abstract The main goal of the current study is to biosynthesize titanium dioxide nanoparticles (TiO 2 -NPs) using green approach to biocontrol of different fungal strains isolated from historical Description of Egypt book. Nineteen fungal strains were isolated from deteriorated parts and identified by the traditional and molecular methods as Aspergillus flavus (8-isolates), Aspergillus versicolor (2-isolates), Aspergillus ustus (4-isolates), Aspergillus chinensis (2-isolates), Penicillium citrinum (2-isolates), and Penicillium chrysogenum (1-isolate). These fungal strains showed high cellulase, amylase, pectinase, and gelatinase activities which have a significant role in biodeterioration. The biomass filtrate of probiotic strain, Lactobacillus rhamnosus , was used to fabricate TiO 2 -NPs which characterized by UV-Vis, FT-IR, XRD, TEM, SEM, EDX, DLS, and zeta potential. The obtained data showed the successful formation of spherical and anatase phase NPs with sizes of 3–7 nm and zeta potential values of – 19.9 and – 36.8 mV. The main components of as-formed nanomaterial were Ti and O with weight percentages of 55.91 and 46.25, respectively. The biocompatibility of synthesized TiO 2 -NPs was investigated toward two normal cell lines, WI38 and HFB4, which reveal the low toxicity at high concentrations (IC 50 > 300 μg mL –1 ). Therefore, concentrations ≤ 300 μg mL –1 were used to biocontrol of isolated fungi. Data showed the promising activity of various concentrations (300, 200, and 100 μg mL –1 ) of TiO 2 -NPs to inhibit the growth of fungal strains with varied inhibition zones and dose-dependent manner. This study exhibited the efficacy of probiotic bacterial strains in the synthesis of TiO 2 -NPs that can be used to preserve historical books from fungal deterioration. Graphical Abstract