Yeast Extract Mannitol medium and its constituents promote synthesis of Au nanoparticles

► Yeast Extract Mannitol medium promote synthesis of Au-nanoparticles. ► Yeast extract as well as mannitol possess potential to generate Au-nanoparticles. ► Au nanoparticles were crystalline and spherical in size range 4-20 nm. ► Do not include metal salts in the microbial culture media for true impact assessment studies.