Reduction of metal is an important defense mechanism in microorganisms as a way to manage metal toxicity. The inherent, clean, nontoxic and environmentally friendly ability of eukaryotic and prokaryotic microorganisms to form the metal nanoparticles is particularly important in the development of nanobiotechnology. New methods have been developed to control disparity, chemical composition, the size, and the shape to get the best particles which can be well applied in different fields of science.

Scientists searching for extraterrestrial life forms have recently begun to focus their attention on a group of icy bodies in the outer solar system. These satellites, particularly Europa, Enceladus, Titan and Triton, are thought to contain both organic molecules and liquid water, and, unlike the organic-rich comets and meteorites of the inner solar system, may also have suitable energy sources for simple organic chemistry to proceed.