Stenotrophomonas and Microbacterium: Mediated Biogenesis of Copper, Silver and Iron Nanoparticles—Proteomic Insights and Antibacterial Properties Versus Biofilm Formation

Abstract

Nanoparticle biosynthesis mediated by plants, microbes, fungus or algae is a safe and eco-friendly approach addressing various applications in the medicine, cosmetics, biosensors and agricultural industry. Morphology of the synthesized particles depends largely on the type of organism involved, culture-conditions like temperature, pH and the substrate-concentration. This paper reports the synthesis of copper, silver and iron NPs by exposing living cells of D−4 strain of Microbacterium marinilacus and III−5 strain of Stenotrophomonas maltophilia to aqueous solutions of Cu2+, Ag2+ and Fe3+ ions. These strains were isolated from Damodar-river sediments in Burnpur, Asansol, India and identified by 16S rDNA-sequencing and phylogenetic-tree analysis. NCBI GenBank Accession No. was KT346339 for III−5 and KT346340 for D−4 isolates respectively. UV-spectrophotometer-analysis of culture supernatant and scanning electron microscopy confirmed biogenesis of the nanoclusters. X-ray diffraction and Fourier transformed infrared spectroscopy further confirmed the nano-dimension of the particles. Atomic force microscopy revealed the conformation of nanoparticles. Antibacterial properties of the synthesized particles against gram positive Bacillus cereus and gram negative Escherichia coli were studied through agar-plate-well-diffusion. Effects of the particles on growth of S. maltophilia PM102 were monitored. Data-analysis with one-way-ANOVA and Tukey’s-HSD-test was done. Protein-profile of the isolates in the presence and absence of nanoparticles was studied through SDS-PAGE.