Bio-traps containing Bio-Sep® beads have now been used to monitor subsurface microbial communities in soil where crude oil was remediated with and without fertilizer addition and in associated tilled and undisturbed prairie controls. Beads were deployed at three depths (1, 3, and 5 inches) in each plot in triplicate in mesh bags or five weeks in May and June, 2003. The soil surrounding the beads was also retrieved. Triplicates (soil and beads) were then composite and analyzed for biomarkers including phospholipids fatty acids and 16S rDNA.

The microbial communities in the beads were found to be enriched in C₁₆ fatty acids relative to the soil communities, were more aerobic in character, and exhibited faster growth rates. Bead communities were less diverse than soil communities and dominant bacteria in the soil were not necessarily dominant in the beads.

Lastly, differences could be seen in beads communities within the same plot at different depths which was not the case for soils. Bio-Sep® beads appear to offer potential advantages over soil analysis in the sampling of soil microbial communities in terms of selection of the more active community members and detection of subtle differences with depth.