Beggiatoa is a genus of bacteria in the order Thiotrichales. They are named after the Italian medic and botanist F.S. Beggiato. The organisms live in sulfur-rich environments. During his research in Anton de Bary’s laboratory of botany in 1887, Russian botanist Sergei Winogradsky found that Beggiatoa oxidized hydrogen sulfide (HS) as an energy source, forming intracellular sulfur droplets. Winogradsky referred to this form of metabolism as inorgoxidation (oxidation of inorganic compounds). The finding represented the first discovery of lithotrophy. Up to now there is only one species of this genus known ( Beggiatoa alba).