Document Type : Research Paper

Authors

• Atieh Sadat Razavi ¹
• Parisa Tajer Mohammad Ghazvini ²
• javad hamedi ³

¹ Department of Microbiology,Tehran Medical Sciences,Islamic Azad University,Tehran,Iran

² Materials and Nuclear Fuel Research School, Nuclear Science and Technology Research Institute, Tehran, Iran

³ Department of Biology, Faculty of Science, University of Tehran, Tehran, Iran

Abstract

Biomineralization of selenium by bacteria not only has the potential to remove toxic selenium oxyanions from the environment, but can also produce nano- scale elemental selenium. In this work, the response surface method (RSM) based on the Box- Behnken design was used for evaluation and optimization of the different process parameters effect on the bioreduction process of selenate. The proposed second order model with a correlation coefficient R2 = 0.96 appropriately predicted the process behavior and determined the 41.25 percent reduction of selenate by Bacillus sp. Strain TR-6 at 5.24 percent initial bacterial inoculation, process time of 24 h and 3.8 mM concentration of sodium selenate as the optimum condition. Scanning electron microscope (SEM) with the Energy Dispersive X-ray spectroscopy (EDX) confirmed the ability of the selected bacteria to produce selenium nanospheres. Finally, Bacillus sp. Strain TR-6 is determined as a valuable candidate for nano- technologies and selenium biomineralization processes.

Keywords

• Bacterial Reduction
• Selenium Oxyanions
• Experimental Design
• Nanobiotechnology