Adaptation to and biodegradation of xenobiotic compounds by microbial communities from a pristine aquifer
The ability of subsurface microbial communities to adapt to the biodegradation of xenobiotic compounds was examined in aquifer solids samples from a pristine aquifer. An increase in the rates of mineralization of /sup 14/C labeled substrates with exposure was used as an indication of adaptation. For some compounds, such as chlorobenzene and 1,2,4-trichlorobenzene, slight mineralization was observed but no adaptation was apparent during incubations of over 8 months. Other compounds demonstrated three patterns of response. For m-cresol, m-aminophenol, and aniline intermediate rates of biodegradation and a linear increase in the percent mineralized with time were observed. Phenol, p-chlorophenol, and ethylene dibromide were rapidly metabolized initially, with a nonlinear increase in the percent mineralized with time, indicating that the community was already adapted to the biodegradation of these compounds. Only p-nitrophenol demonstrated a typical adaptation response. In different samples of soil from the same layer in the aquifer, the adaptation period to p-nitrophenol varied from a few days to as long as 6 weeks. In most cases the concentration of xenobiotic added, over the range from a few nanograms to micrograms per gram, made no difference in the response. Most-probably-number counts demonstrated that adaptation is accompanied by an increase in specific degrader numbers. This study has shown that diverse patterns of response occur in the subsurface microbial community.
- Research Organization:
- Univ. of North Carolina, Chapel Hill
- OSTI ID:
- 5764781
- Journal Information:
- Appl. Environ. Microbiol.; (United States), Vol. 53:9
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
59 BASIC BIOLOGICAL SCIENCES
ANILINE
BIODEGRADATION
CHLORINATED AROMATIC HYDROCARBONS
CRESOLS
MICROORGANISMS
BIOLOGICAL ADAPTATION
NITROPHENOL
ORGANIC BROMINE COMPOUNDS
PHENOLS
AQUIFERS
CARBON 14 COMPOUNDS
MINERALIZATION
SOILS
TRACER TECHNIQUES
XENOBIOTICS
AMINES
AROMATICS
CHEMICAL REACTIONS
DECOMPOSITION
HALOGENATED AROMATIC HYDROCARBONS
HYDROXY COMPOUNDS
ISOTOPE APPLICATIONS
LABELLED COMPOUNDS
NITRO COMPOUNDS
ORGANIC CHLORINE COMPOUNDS
ORGANIC COMPOUNDS
ORGANIC HALOGEN COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
560300* - Chemicals Metabolism & Toxicology
550501 - Metabolism- Tracer Techniques