Abstract: The biomass D01 was screened from the soil of mining area and it was identified as Bacillus megatherium.It is able to adsorb and reduce the noble metal ions such as Pd²⁺,Au³⁺and Ag⁺etc.at room temperature.At pH3.5, the adsorbed ratio were 93.2%,99.5% and 98.1%, respectively within₂h.In situ TEM images showed that the Au, Ag particles adsorbed on the cell wall grew up gradually.Some of the Au particles formed polyhedron particles, while some ones broke off from the cell.The particle size can be controlled to be several nano-meters to more than a hundred nano-meters.XPS and XRD results indicated that Au³⁺, Ag⁺and Pd²⁺could be reduce to metals much faster than Rh³⁺and Pt⁴⁺by Dol.Peaks at 3087 and 1664 cm^-1in the IRspectra of D01 reduced gradually while interacting with metal ions, implying that metal ions were coordinated and reduced on the site of acylamide of D01.This is a promising method for preparation of metal catalysts with high dispersion and nano-meter sized metal particles.

Key words: Bacteria, Noble metal, Reduction