Biomass and salt-dependent effects of Bacillus spores on radionuclide migration from the Waste Isolation Pilot Plant.

Spores of a Bacillus sp., isolated from radioactive waste, were tested for their ability to influence the fate and transport of neodymium (Nd) under high salt conditions expected at the Waste Isolation Pilot Plant (WIPP) nuclear waste repository. Spores were suspended in neodymium-spiked saline solutions up to 4 M NaCl, and concentrations of Nd and the complexing agent dipicolinic acid (DPA), a component of spores, were monitored along with optical densities and spore numbers.