Patent ID: 8003071

Claim:
A process for producing uniformly sized elemental selenium nanospheres having an average diameter in the range of 50-500 nm, comprising the steps of a) growing non-toxic non-selenium-respiring bacteria in a medium comprising selenite ions in a non-limiting concentration for a time period being sufficiently long for the formation of spherical elemental selenium inclusion bodies within said bacteria, wherein said bacteria are selected from bacteria belonging to the genera Bifidobacterium, Lactobacillus or Streptococcus , and wherein said medium used for growing said bacteria is a liquid culture medium comprising selenium in 2-200 mg/L concentration, in the form of a selenite salt; and b) partially or fully purifying said spherical elemental selenium inclusion bodies from said bacteria and/or medium, wherein the actual size of said nanospheres produced being defined by the specific bacterium species selected in step a).