Photocatalytic decolorization of bromothymol blue using biogenic selenium nanoparticles synthesized by terrestrial actinomycete Streptomyces griseobrunneus strain FSHH12

The aim of the present study was to isolate and identify a terrestrial actinomycete bacterial strain capable to produce selenium nanoparticles (Se NPs) followed by purification of the biogenic Se NPs and evaluation of their photocatalytic degradation compared to selenium dioxide. Among 30 actinomycete bacterial strains obtained from environmental soil samples, one isolate (identified as Streptomyces griseobrunneus strain FSHH12 based on the 16S rDNA gene sequence analysis) was selected and used for production of Se NPs. The biologically synthesized Se NPs was consequently purified by an organic-aqueous partitioning system and characterized using scanning electron microscopy, transmission electron microscopy, energy dispersive X-ray, UV-visible spectroscopy, Fourier transform infrared spectroscopy, and X-ray diffraction spectroscopy. The obtained results of photocatalytic degradation of bromothymol blue using the purified Se NPs (64g/mL) revealed 62.3% of dye removal under UV illumination (15W) after 60min incubation of dye solution.