Metabolism of benzene, toluene, and xylene hydrocarbons in soil
- Rutgers--the State Univ., New Brunswick, NJ (United States)
Enrichment cultures obtained from soil exposed to benzene, toluene, and xylene (BTX) mineralized benzene and toluene but cometabolized only xylene isomers, forming polymeric residues. This observation prompted the authors to investigate the metabolism of {sup 14}C-labeled BTX hydrocarbons in soil, either individually or as mixtures. BTX-supplemented soil was incubated aerobically for up to 4 weeks in a sealed system that automatically replenished any O{sub 2} consumed. The decrease in solvent vapors and the production of {sup 14}CO{sub 2} were monitored. At the conclusion of each experiment, {sup 14}C distribution in solvent-extractable polymers, biomass, and humic material was determined, obtaining {sup 14}C mass balances of 85 to 98%. BTX compounds were extensively mineralized in soil, regardless of whether they were presented singly or in combinations. No evidence was obtained for the formation of solvent-extractable polymers from xylenes in soil, but {sup 14}C distribution in biomass and humus was unusual for all BTX compounds and especially for toluene and the xylenes. The results suggest that catechol intermediates of BTX degradation are preferentially polymerized into the soil humus and that the methyl substituents of the catechols derived from toluene and especially from xylenes enhance this incorporation. In contrast to inhibitory residues formed from xylene cometabolism in culture, the humus-incorporated xylene residues showed no significant toxicity in the Microtox assay.
- OSTI ID:
- 302305
- Journal Information:
- Applied and Environmental Microbiology, Journal Name: Applied and Environmental Microbiology Journal Issue: 12 Vol. 64; ISSN AEMIDF; ISSN 0099-2240
- Country of Publication:
- United States
- Language:
- English
Similar Records
Interactions between benzene, toluene, and p-xylene (BTX) during their biodegradation
Anaerobic degradation of toluene and xylene by aquifer microorganisms under sulfate-reducing conditions