Obligate methylotrophic bacteria are traditional biotechnological producers due to their ability to grow rapidly in extremely simple growth media. The aim of this study was to isolate a highly efficient methylotrophic producer from natural sources specifically for the “green” synthesis of metal nanoparticles. It was demonstrated that a pure bacterial culture of the genus Methylophilus is the most technologically advanced for the active biosynthesis of gold nanoparticles (AuNPs). The optimal cond