As a key part of water management at the Ranger Uranium Mine (Northern 
Territory, Australia), stockpile (ore and waste) runoff water was applied to 
natural woodland on the mine lease in accordance with regulatory requirements. 
Consequently, the soil in these Land Application Areas (LAAs) presents a range 
of uranium concentrations. Soil samples were collected from LAAs with different 
concentrations of uranium and extracts were plated onto LB media containing no 
(0 ppm), low (3 ppm), medium (250 ppm), high (600 ppm) and very high (1500 ppm) 
uranium concentrations. These concentrations were similar to the range of 
measured uranium concentrations in the LAAs soils. Bacteria grew on all plates 
except for the very high uranium concentrations, where only fungi were 
recovered. Identifications based on bacterial 16S rRNA sequence analysis showed 
that the dominant cultivable bacteria belonged to the genus Bacillus. Members of 
the genera Paenibacillus, Lysinibacillus, Klebsiella, Microbacterium and 
Chryseobacterium were also isolated from the LAAs soil samples. Fungi were 
identified by sequence analysis of the intergenic spacer region, and members of 
the genera Aspergillus, Cryptococcus, Penicillium and Curvularia were dominant 
on plates with very high uranium concentrations. Members of the Paecilomyces and 
Alternaria were also present but in lower numbers. These findings indicate that 
fungi can tolerate very high concentrations of uranium and are more resistant 
than bacteria. Bacteria and fungi isolated at the Ranger LAAs from soils with 
high concentrations of uranium may have uranium binding capability and hence the 
potential for uranium bioremediation.