Reduction of Selenite to Red Elemental Selenium by Rhodopseudomonas palustris Strain N.

PloS one

PubMedID: 24759917

Li B, Liu N, Li Y, Jing W, Fan J, Li D, Zhang L, Zhang X, Zhang Z, Wang L. Reduction of Selenite to Red Elemental Selenium by Rhodopseudomonas palustris Strain N. PLoS ONE. 2014;9(4):e95955.
The trace metal selenium is in demand for health supplements to human and animal nutrition. We studied the reduction of selenite (SeO3-2) to red elemental selenium by Rhodopseudomonas palustris strain N. This strain was cultured in a medium containing SeO3-2 and the particles obtained from cultures were analyzed using transmission electron microscopy (TEM), energy dispersive microanalysis (EDX) and X ray diffraction analysis (XRD). Our results showed the strain N could reduce SeO3-2 to red elemental selenium. The diameters of particles were 80-200 nm. The bacteria exhibited significant tolerance to SeO3-2 up to 8.0 m mol/L concentration with an EC50 value of 2.4 m mol/L. After 9 d of cultivation, the presence of SeO32- up to 1.0 m mol/L resulted in 99.9% reduction of selenite, whereas 82.0% (p<0.05), 31.7% (p<0.05) and 2.4% (p<0.05) reduction of SeO3-2 was observed at 2.0, 4.0 and 8.0 m mol/L SeO32- concentrations, respectively. This study indicated that red elemental selenium was synthesized by green technology using Rhodopseudomonas palustris strain N. This strain also indicated a high tolerance to SeO3-2. The finding of this work will contribute to the application of selenium to human health.