Survival of added bacterial species and metabolism of toxic compounds in natural environments
Bacteria able to degrade either 2,4-dichlorophenol (DCP) or phenanthrene (PHEN) were isolated from polluted freshwater environments. Two isolates able to degrade each compound were tested for mineralization with a sensitive /sup 14/C assay and for survival in lake water and sewage using a selective medium. One DCP isolate was identified as Alcaligenes paradoxus and the other as Alcaligenes sp. One PHEN isolate was identified as Pseudomonas fluorescens and the other as Pseudomonas sp. All four isolates survived and grew in sterile environments which indicated that starvation would not be a factor in survival of these strains. The number of organisms declined immediately in number in nonsterile lake water. However, they did survive or even grow in nonsterile sewage for a short period before declining in number. Biotic factors appeared to be influential for survival and mineralization of target compounds in many environments. The removal of protozoa, which prey on bacteria, improved survival of the added cells, but had no influence on the mineralization of 10 ..mu..g DCP/L. In comparison, degradation of 10 and 25 mg DCP/L stopped after a few days. Yeast nitrogen base appeared to overcome the lack of nutrient regeneration, a function attributed to protozoa. The additional nutrients increased toxicant mineralization, especially when seeded with appropriate species. Thus, protozoa may limit growth of added cells but appear to be needed for mineralization of higher concentrations of DCP.
- Research Organization:
- Memphis State Univ., TN (USA)
- OSTI ID:
- 6277243
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
560300* -- Chemicals Metabolism & Toxicology
59 BASIC BIOLOGICAL SCIENCES
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ANIMALS
AROMATICS
BACTERIA
BIODEGRADATION
CARBON 14 COMPOUNDS
CHEMICAL REACTIONS
CHLORINATED AROMATIC HYDROCARBONS
CONDENSED AROMATICS
DECOMPOSITION
FRESH WATER
GROWTH
HALOGENATED AROMATIC HYDROCARBONS
HYDROCARBONS
HYDROGEN COMPOUNDS
INVERTEBRATES
LABELLED COMPOUNDS
MICROORGANISMS
MINERALIZATION
ORGANIC CHLORINE COMPOUNDS
ORGANIC COMPOUNDS
ORGANIC HALOGEN COMPOUNDS
OXYGEN COMPOUNDS
PHENANTHRENE
POLLUTION
PROTOZOA
PSEUDOMONAS
RADIOASSAY
SURVIVAL TIME
WATER
WATER POLLUTION