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Title: 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 nutrientsmore » 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.« less
Authors:
Publication Date:
OSTI Identifier:
6277243
Resource Type:
Thesis/Dissertation
Resource Relation:
Other Information: Thesis (Ph. D.)
Publisher:
Memphis State Univ.,Memphis, TN
Research Org:
Memphis State Univ., TN (USA)
Country of Publication:
United States
Language:
English
Subject:
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.; 59 BASIC BIOLOGICAL SCIENCES; BACTERIA; SURVIVAL TIME; CHLORINATED AROMATIC HYDROCARBONS; BIODEGRADATION; PHENANTHRENE; CARBON 14 COMPOUNDS; FRESH WATER; GROWTH; MINERALIZATION; PROTOZOA; PSEUDOMONAS; RADIOASSAY; WATER POLLUTION; ANIMALS; AROMATICS; CHEMICAL REACTIONS; CONDENSED AROMATICS; DECOMPOSITION; HALOGENATED AROMATIC HYDROCARBONS; HYDROCARBONS; HYDROGEN COMPOUNDS; INVERTEBRATES; LABELLED COMPOUNDS; MICROORGANISMS; ORGANIC CHLORINE COMPOUNDS; ORGANIC COMPOUNDS; ORGANIC HALOGEN COMPOUNDS; OXYGEN COMPOUNDS; POLLUTION; WATER 560300* -- Chemicals Metabolism & Toxicology; 550501 -- Metabolism-- Tracer Techniques