Metabolic diversity of aromatic hydrocarbon-degrading bacteria from a petroleum-contaminated aquifer

Mark D. Mikesell, Jerome J. Kukor, Ronald H. Olsen

Research output: Contribution to journalArticlepeer-review

69 Scopus citations


We characterized bacteria from contaminated aquifers for their ability to utilize aromatic hydrocarbons under hypoxic (oxygen-limiting) conditions (initial dissolved oxygen concentration about 2 mg/l) with nitrate as an alternate electron acceptor. This is relevant to current intense efforts to establish favorable conditions for in situ bioremediation. Using samples of granular activated carbon slurries from an operating groundwater treatment system, we isolated bacteria that are able to use benzene, toluene, ethylbenzene, or p-xylene as their sole source of carbon under aerobic or hypoxic-denitrifying conditions. Direct isolation on solid medium incubated aerobically or hypoxically with the substrate supplied as vapor yielded 103 to 105 bacteria ml-1 of slurry supernatant, with numbers varying little with respect to isolation substrate or conditions. More than sixty bacterial isolates that varied in colony morphology were purified and characterized according to substrate utilization profiles and growth condition (i.e., aerobic vs. hypoxic) specificity. Strains with distinct characteristics were obtained using benzene compared with those isolated on toluene or ethylbenzene. In general, isolates obtained from direct selection on benzene minimal medium grew well under aerobic conditions but poorly under hypoxic conditions, whereas many ethylbenzene isolates grew well under both incubation conditions. We conclude that the conditions of isolation, rather than the substrate used, will influence the apparent characteristic substrate utilization range of the isolates obtained. Also, using an enrichment culture technique, we isolated a strain of Pseudomonas fluorescens, designated CFS215, which exhibited nitrate dependent degradation of aromatic hydrocarbons under hypoxic conditions.

Original languageEnglish (US)
Pages (from-to)249-259
Number of pages11
Issue number4
StatePublished - Dec 1993
Externally publishedYes

All Science Journal Classification (ASJC) codes

  • Environmental Engineering
  • Microbiology
  • Bioengineering
  • Environmental Chemistry
  • Pollution


  • Pseudomonas
  • aromatic hydrocarbons
  • biodegradation
  • bioremediation
  • denitrification
  • groundwater

Fingerprint Dive into the research topics of 'Metabolic diversity of aromatic hydrocarbon-degrading bacteria from a petroleum-contaminated aquifer'. Together they form a unique fingerprint.

Cite this