Figure 2.

Epifluorescent images (microbes appear as bright spots) of pyrite powder after various reaction conditions. (a) Pyrite exposed to bacteria for 10 days; (b) lipid/pyrite exposed to bacteria for 10 days; (c) a different pyrite sample exposed to bacteria for 10 days and the (d) same sample after vortexing. These images suggest that A. ferrooxidans colonize untreated pyrite surfaces and that the presence of lipids inhibits this colonization. The scale bar for all the images is 10 μm.