GLOSSARY - Bioaugmentation for Groundwater Remediation - page 363

Biomass ‐ Total mass of microorganisms present in a given amount of water or soil.

Bioremediation ‐ Use of microorganisms to control and destroy contaminants.

Biostimulation ‐ The modification of the subsurface to stimulate existing bacteria capable of
bioremediation.

Biotransformation ‐ Biologically catalyzed transformation of a chemical to some other
product.

Capture zone ‐ The three-dimensional region that contributes the groundwater extracted by
one or more wells or drains.

Catalyst ‐ A substance that promotes a chemical reaction but does not itself enter into the

reaction.

Chlorinated solvent ‐ A hydrocarbon in which chlorine atoms substitute for one or more
hydrogen atoms in the compound's structure. Chlorinated solvents commonly are used for
grease removal in manufacturing, dry cleaning, and other operations. Examples include
trichloroethene (TCE), perchloroethene (PCE), and trichloroethane (TCA).

‐ A substance that enhances the action of an enzyme.

Coenzyme

Cometabolism ‐ The simultaneous metabolism of two compounds in which the degradation
of the second compound (the secondary substrate) depends on the presence of the first
compound (the primary substrate). For example, in the process of degrading methane, some
bacteria can degrade hazardous chlorinated solvents that they would otherwise be unable to
attack.

Compound specific isotope analysis (CSIA) ‐ Isotopic characterization of individual
compounds that can be used to assess degradation processes.

Conjugation ‐ The direct transfer of genetic material from one cell to another.

Daughter products ‐ Generally refers to compounds produced during the degradation of
other “parent” compounds. In the case of chlorinated ethenes, PCE and TCE are generally the
parent compounds, and dichloroethene (DCE) and vinyl chloride (VC) are the daughter
products.

Dechlorination ‐ A type of dehalogenation reaction involving replacement of one or more
chlorine atoms with hydrogen.

Degradation ‐ The transformation of a compound through biological or abiotic reactions.

Deoxyribonucleic acid (DNA) ‐ A nucleic acid that is the primary component of the

chromosones of all organisms.

Dehalococcoides ) ‐ A genus of bacteria within class Dehalococcoidetes that obtain

energy via the oxidation of hydrogen gas and subsequent reductive dehalogenation of
halogenated organic compounds.

( Dhc