%0 Journal Article %T Investigation of Desulfurization Activity, Reusability, and Viability of Magnetite Coated Bacterial Cells %J Iranian Journal of Biotechnology %I National Institute of Genetic Engineering and Biotechnology of Iran %Z 1728-3043 %A Bardania, Hassan %A Raheb, Jamshid %A Arpanaei, Ayyoob %D 2019 %\ 06/01/2019 %V 17 %N 2 %P 14-20 %! Investigation of Desulfurization Activity, Reusability, and Viability of Magnetite Coated Bacterial Cells %K Rhodococcus erythropolis %K Nanoparticles %K Equipment Reuse %R 10.21859/ijb.2108 %X Background: Magnetic separation using magnetic nanoparticles can be used as a simple method to isolate desulfurizing bacteria from a biphasic oil/water system. Objectives: Magnetite nanoparticles were applied to coat the surface of Rhodococcus erythropolis IGTS8 and Rhodococcus erythropolis FMF desulfurizing bacterial cells, and the viability and reusability of magnetite-coated bacteria evaluated by using various methods. Material and Methods: Magnetite nanoparticles were synthesized through a reverse co-precipitation method. Glycine was added during and after the synthesis of magnetite nanoparticles to modify their surface and to stabilize the dispersion of the nanoparticles. The glycine-modified magnetite nanoparticles were immobilized on the surface of both oil-desulfurizing bacterial strains. Reusability of magnetite-coated bacterial cells was evaluated via assessing the desulfurization activity of bacteria via spectrophotometry using Gibb's assay, after the separation of bacterial cells from 96h-cultures with the application of external magnetic field. In addition, CFU and fluorescence imaging were used to investigate the viability of magnetite-coated and free bacterial cells. Results: TEM micrographs showed that magnetite nanoparticles have the size approximately 5.35±1.13 nm. Reusability results showed that both magnetite-coated bacterial strains maintain their activity even after 5 × 96h-cycles. The viability results revealed glycine-modified magnetite nanoparticles did not negatively affect the viability of two bacterial strains R. erythropolis IGTS8 and R. erythropolis FMF. Conclusions: In conclusion, the glycine-modified magnetite nanoparticles have great capacity for immobilization and separation of desulfurizing bacteria from suspension. %U https://www.ijbiotech.com/article_85181_5fc3800f79a11b1fd52f367067a3dbc7.pdf