Characteristics of Bacillus cereus Spore Counts in Soils with Underlying Gold Mineralization in Northwestern Sichuan, China. Results from a Pilot Study

A pilot survey on a microbial mineral exploration method based on soil Bacillus cereus spore counts was carried out across three different gold mining regions, which vary in soil type, climate condition and geological setting in northwestern Sichuan, China. B-horizon soils from these sites were analyzed for B. cereus spores, Au, Ag, Cu, Pb and Zn. The results show that the numbers of B. cereus spores generally increased in soils overlying gold mineralization. Specifically, elevated spore counts were found in samples slightly offset from the outcrops of orebodies, whereas soils directly above the outcrops of orebodies usually contained low spore counts. However, the background counts of B. cereus spores varied from place to place and were complicated by enviromnental and pedological factors, but the relative ratios of spore counts still were indicative of the underlying gold mineralization.