Aerobic thermophile biodegradation of BTEX
- Lawrence Livermore National Lab., CA (United States)
In the aftermath of heat-driven subsurface remediation efforts such as steam stripping or Joule heating for cleaning up fuel spills, there will be a time during which the entire underground environment remains at temperatures significantly higher than ambient. The possible use of thermophilic bacteria capable of degrading select fuel hydrocarbons would take advantage of these higher underground temperatures to enhance the removal of low levels of residual regulated fuel contaminants. Twenty six thermophilic bacteria strains from the American Type Culture Collection were screened and two aerobes, Thermus aquaticus (ATCC 25104) and Thermus sp. (ATCC 27978), were found to degrade BTEX (benzene, toluene, ethylbenzene, and xylenes), common contaminants from gasoline storage-tank leakages. T. aquaticus and Thermus sp. were grown in a modified ATCC medium at 70{degrees}C and 61{degrees}C, respectively, and resting cell suspensions were used to study BTEX biodegradation at the same corresponding temperatures. The degradation of BTEX by these cell suspensions in sealed culture bottles was measured against controls that also displayed significant abiotic removals of BTEX under such high temperature conditions. Raising the BTEX concentration lowered the extent of biodegradation. The biodegradations of both benzene and toluene were enhanced when T. aquaticus and Thermus sp. were pregrown on catechol and o-cresol, respectively, as carbon sources. Use of [U-{sup 14}C]benzene and [U-{sup 14}C]toluene verified that a small fraction of these two compounds were metabolized to water-soluble products and CO{sup 2} by these non-growing cell suspensions within 7 days. This study represents the first time members of the naturally occurring, common thermophilic genus Thermus have been shown to have a co-metabolic potential for contaminant VOC degradation.
- OSTI ID:
- 126133
- Report Number(s):
- CONF-950402-; TRN: 95:006086-0106
- Resource Relation:
- Conference: 209. American Chemical Society (ACS) national meeting, Anaheim, CA (United States), 2-6 Apr 1995; Other Information: PBD: 1995; Related Information: Is Part Of 209th ACS national meeting; PB: 2088 p.
- Country of Publication:
- United States
- Language:
- English
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