Application of the luminous bacterium Photobacterium phosphoreum for toxicity monitoring of selenite and its reduction to selenium(0) nanoparticles

• Published in: Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy Molecular and biomolecular spectroscopy, 2025-01, Vol.325, p.125078, Article 125078
• Main Authors: Zenkov, Andrei V., Sushko, Ekaterina S., Mogilnaya, Olga A., Volochaev, Mikhail N., Shabanov, Alexandr V., Kamnev, Alexander A., Tugarova, Anna V., Kudryasheva, Nadezhda S.
• Format: Article
• Language: English
• Subjects: Biotransformation; Luminous marine bacteria; Reactive oxygen species; Selenium nanoparticles; Sodium selenite; Toxicity
• ISSN: 1386-1425
• DOI: 10.1016/j.saa.2024.125078

[Display omitted] •Luminescence of marine bacteria can be used to monitor toxicity of selenite ions.•Bioluminescence activation and inhibition by SeO32− is defined by ROS content.•Bacteria change the ROS content in aqueous solutions of selenite.•Marine bacteria reduce selenite ions to form elemental selenium.•Luminous marine bacteria produce selenium nanoparticles. Luminous marine bacteria are traditionally used as a bioassay due to the convenience and high rate of registering the intensity of their physiological function – luminescence. This study aimed to develop the application of Photobacterium phosphoreum in traditional and novel fields – toxicity monitoring and biotechnology. We demonstrated (1) effects of selenite ions on bioluminescence, and (2) biotransformation of selenite to selenium(0) in the form of nanoparticles. The effects of selenite (SeO32−) on the intensity of bacterial bioluminescence were studied, and its dependencies on exposure time and concentration of Na2SeO3 were analyzed. Bioluminescence activation and inhibition were revealed; dose–effect dependencies corresponded to the hormesis model. The toxicity of SeO32− was characterized by an effective concentration of 10−3 M. Effects of SeO32− on reactive oxygen species (ROS) in bacterial suspensions were studied. High positive correlations were found between the bioluminescence intensity and ROS content, which indicates the decisive role of ROS and associated redox processes in the bioeffects of selenite ions. Scanning and transmission electron microscopy revealed the presence of nano-structures in the bacteria exposed to selenite. The energy dispersion spectrum detected a high content of selenium in the nanoparticles. The particle size distribution depended on Na2SeO3 concentration; maxima of the distribution varied within 45–55 nm.