A passive approach to microbial sampling
While traditional groundwater samples are often used for PLFA and CENSUS analyses, standard Bio-Traps offer key advantages for routine monitoring of microbial communities. Analogous to passive diffusion samplers for VOCs, Bio-Traps provide an integrated or “time averaged” picture of the microbial community rather than a onetime “snapshot” sampling event. In general, this integrated microbial community response over time (30–60 days) leads to less inherent variability than observed with groundwater samples. Furthermore, organisms must colonize the beads in order to be collected for subsequent analyses. Therefore, the microbial communities colonizing the Bio-Traps are more likely to represent the active members of the subsurface microbial community.