Role of Denitrification in Selenite Reduction by Azospirillum brasilense with the Formation of Selenium Nanoparticles

Evidence has been presented for the first time for bacteria of the genus <i>Azospirillum</i> that the denitrification pathway known to be inherent in these bacteria, including nitrite reductase, is likely to be involved in selenite reduction. The results using BSO also imply that detoxification of selenite through the GSH redox system (which is commonly considered as the primary mechanism of selenite reduction in many bacteria) does not play a significant role in <i>A.brasilense</i>. The acquired knowledge on the mechanisms underlying biogenic transformations of inorganic selenium in <i>A.brasilense</i> is a step forward both in understanding the biogeochemical selenium cycle and to a variety of potential nano- and biotechnological applications.