Biodegradation and biotransformation of groundwater pollutants, when present as mixtures, by soil microorganisms

Thesis/Dissertation · Sat Jan 01 04:00:00 EST 1994

OSTI ID:7286065

Burback, B L

The ability of soil microorganisms to metabolize mixtures of groundwater pollutants in pure culture and defined mixed culture was investigated. Mycobacterium vaccae strain JOB-5 catabolized acetone, cyclohexane, styrene, benzene, ethylbenzene, propylbenzene, dioxane and 1,2 dichloroethylene. Analysis indicated that the products of benzene degradation by M. vaccae were phenol and hydroquinone. The products of chlorobenzene, ethylbenzene, and propylbenzene degradation were identified as 4-chlorophenol, 4-ethylphenol, and 4-propylphenol. When toluene and benzene were present concomitantly toluene was degraded first. The presence of toluene promoted the degradation of styrene. These results suggested that components in mixtures may have a positive or a negative effect on the rates of biodegradation of other pollutants. The toxicity of seven major groundwater pollutants (benzene, chlorobenzene, propylbenzene, ethylbenzene, trichloroethylene, toluene, and styrene) and their metabolites to a soil mycobacterium (Mycobacterium vaccae strain JOB-5) that catabolized these pollutants was determined. Three metabolites were less toxic to M. vaccae than their parent compound. Three of the pollutants were less toxic than their metabolites. The metabolites 4-chlorophenol, 4-ethylphenol, and 4-propylphenol all inhibited the degradation of toluene by M. vaccae. A culture containing Mycobacterium vaccae and Rhodococcus sp. (strain R-22) was investigated to determine the effect two organisms would have on the catabolism of groundwater pollutants. The mixture mineralized benzene to CO[sub 2] at five times the amount of pure cultures. The physiological mechanism is described. This study demonstrates the complex interactions involved in the biodegradation of mixed groundwater pollutants.

• Research Organization: North Carolina State Univ., Raleigh, NC (United States)
• OSTI ID: 7286065
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
540300* -- Environment
Aquatic-- (1990-)
ALKYLATED AROMATICS
AROMATICS
BACTERIA
BENZENE
BIODEGRADATION
BIOLOGICAL PATHWAYS
CHEMICAL REACTIONS
CONTAMINATION
DECOMPOSITION
DISPERSIONS
GROUND WATER
HYDROCARBONS
HYDROGEN COMPOUNDS
MICROORGANISMS
MIXTURES
MYCOBACTERIUM
ORGANIC CHLORINE COMPOUNDS
ORGANIC COMPOUNDS
ORGANIC HALOGEN COMPOUNDS
OXYGEN COMPOUNDS
POLLUTANTS
RHODOCOCCUS
STYRENE
SULFUR-OXIDIZING BACTERIA
TOLUENE
TOXICITY
WATER