|Bio-Trap® samplers are passive sampling tools that collect microbes over time for the purpose of better understanding biodegradation potential. The key to the Bio-Trap® approach is a unique sampling matrix, Bio-Sep® beads, developed in collaboration with the University of Tulsa and the University of Tennessee. The beads are 2-4 mm in diameter and are an engineered composite of Nomex® and powdered activated carbon (PAC). When a Bio-Trap® sampler is deployed in a monitoring well, the Bio-Sep® beads absorb contaminants and nutrients present in the aquifer essentially becoming an in situ microcosm with an incredibly large surface area (~600 m2/g) which is readily colonized by subsurface microorganisms. Once recovered from a monitoring well (30-60 days after deployment), DNA, RNA, or phospholipid fatty acids (PLFA) can be extracted from the beads for CENSUS® or PLFA assays to evaluate the microbial community.|
Standard Bio-Trap samplers in the simplest terms are a replacement for collecting groundwater samples using a conventional approach. Most microbes prefer to be attached to a surface rather than free floating. The Bio-Trap® provides a large surface area for the microbes to colonize and form biofilms. The results generated using this approach have been shown to minimize the variability associated with traditional sampling methods and to reflect the spatial and time dependent changes in the aquifer microbial community structure which is not always evident from groundwater analysis. Standard Bio-Trap® samplers are commonly used during site characterization and routine monitoring to:
- quantify specific microbes or contaminant degrading bacteria (e.g. Dehalococcoides),
- evaluate monitored natural attenuation (MNA),
- compare microbial populations at different sampling points across a site, and
- monitor shifts in microbial communities following enhanced bioremediation (i.e. amendment additions).
Bio-Trap® Samplers can be “baited” with various amendments or compounds to answer site-specific questions and screen remedial alternatives. For example, Bio-Traps can be baited with specific contaminants of concern, various electron donors such as HRC®, EOS®, or lactate, or with inorganic amendments like nitrate or sulfate. For more information on baiting options and applications, please see Bio-Trap In Situ Microcosm.
Bio-Traps can also be baited with 13C labeled compounds (Stable Isotope Probing) to conclusively demonstrate that biodegradation is occurring.