GLOSSARY - Bioaugmentation for Groundwater Remediation - page 372

Polymerase chain reaction (PCR) ‐ Technique to amplify a single or a few copies of a
specific DNA sequence by several orders of magnitude. Allows detection of a target gene or
parts of a gene, even when present at low concentrations in soils or groundwaters, for example.
PCR relies on thermal cycling, consisting of cycles of repeated heating and cooling of the
reaction for DNA melting and enzymatic replication.

Porosity ‐ The fraction of the subsurface volume filled with pores or cavities through which
water or air can move.

‐ A substance separated from a solution or suspension by chemical or physical

Precipitate

change.

Primary substrates ‐ The electron donor and electron acceptor that are essential to ensure the
growth of microorganisms. These compounds can be viewed as analogous to the food and
oxygen that are required for human growth and reproduction.

Protein ‐ Complex nitrogenous organic compounds of high molecular weight made of amino
acids. Essential for growth and tissue repair. Many, but not all, proteins are enzymes.

Proteome ‐ The entire complement of proteins in an organism or sample.

Proteomics ‐ The large-scale study of proteins, particularly their structures and functions.
Studying the proteome of an organism (i.e., all of its proteins) can reveal what enzymes are
present at a given time and under given conditions, for example.

Protonophore ‐ The ionophore carrying protons to facilitate crossing the lipid bilayer.

Pump-and-treat ‐ Remediation strategy involving extraction of groundwater and

aboveground treatment.

qPCR (quantitative polymerase chain reaction) ‐ A laboratory technique used to amplify
and simultaneously quantify a targeted DNA molecule. Also called real-time-PCR.

Radius of influence (ROI) ‐ The radial distance from the center of an injection point or well
to the point where there is no significant impact from the injected material.

Record of Decision ‐ A public document that explains which cleanup alternative(s) will be
used at National Priorities List sites where, under Comprehensive Environmental Response,
Compensation, and Liability Act (CERCLA), trust funds pay for the cleanup.

Redox (redox potential) ‐ Reduction/oxidation reactions in which atoms have their oxidation
number changed. For example, carbon may be oxidized by oxygen to yield carbon dioxide or
reduced by hydrogen to yield methane. The redox potential (ORP) reflects the tendency of a
chemical species to acquire electrons and thereby be reduced. In a redox reaction, one chemical
species—the reductant or reducing agent—loses electrons and is oxidized, and the other—the
oxidant or oxidizing agent—gains electrons and is reduced.

Reducing ‐ Environmental conditions that favor a decrease in the oxidation state of reactive
chemical species (e.g., reduction of sulfates to sulfides).