Assessing the effectiveness of a novel green nano additive using Cytobacillus horneckiae, isolated from biodeteriorated emulsion paint

Abstract

Waterborne acrylic paints are susceptible to decomposition under storage conditions because of colonization by bacterial species. Microbial growth alters pH, gas formation, and viscosity reduction, thereby reducing the product's shelf-life extension. The prevention of emulsion paint deterioration is crucial to mitigate economic losses, and the adverse environmental impact linked to their subsequent disposal. Consequently, evaluating the bioresistance of emulsion paints becomes a matter of paramount significance. In the present research, the effectiveness of a bacterial isolate (Cytobacillus horneckiae) obtained from a biodeteriorated commercial acrylic paint was evaluated as a bioindicator, and bioresistance of paints formulated with nanoparticles (NPs) obtained by green synthesis using aqueous extract of Cecropia pachystachya and Ag salt were evaluated. The Ag NPs were characterized by UV-vis spectrophotometry, scanning electron microscopy (SEM), transmission Electron Microscope (TEM), energy dispersive spectrometer (EDS), X-ray diffraction (XRD), and antimicrobial activity. Waterborne paints were formulated, prepared, and antimicrobial assay was performed. In addition to the isolated bacterium obtained, a strain of Pseudomonas aeruginosa, suggested by the standard ASTM D2574, and adapted to growth in emulsion paint was used. For the first time, it is reported that a paint containing Ag NPs, derived from a green synthesis using Cecropia pachystachya with a low silver concentration (0.018% wt), has completely inhibited bacterial growth under in-can conditions. The bacterial isolate used for assessment was Cytobacillus horneckiae, proving to be an effective bioindicator for evaluating the bioresistance of emulsion paints.