| Abstract | The invention relates to microbiological processes using non-selenium-respiring bacteria for the production of elemental selenium nanospheres having a size in the 50-500 nm range and compositions comprising said nanospheres. The invention further concerns grey elemental selenium nanospheres directly obtainable by the processes of the invention. The compositions and materials of the invention are useful, in particular, as food additives and for use as raw material in the microelectronic and optical industries. |