Low temperature bioremediation of oil-contaminated soil using biostimulation and bioaugmentation with a Pseudomonas sp. from maritime Antarctica.
OBJECTIVE
To identify native Antarctic bacteria capable of oil degradation at low temperatures.


RESULTS
Oil contaminated and pristine soils from Signy Island (South Orkney Islands, Antarctica) were examined for bacteria capable of oil degradation at low temperatures. Of the 300 isolates cultured, Pseudomonas strain ST41 grew on the widest range of hydrocarbons at 4 degrees C. ST41 was used in microcosm studies of low temperature bioremediation of oil-contaminated soils. Microcosm experiments showed that at 4 degrees C the levels of oil degradation increased, relative to the controls, with (i) the addition of ST41 to the existing soil microbial population (bioaugmentation), (ii) the addition of nutrients (biostimulation) and to the greatest extent with (iii) a combination of both treatments (bioaugmentation and biostimulation). Addition of water to oil contaminated soil (hydration) also enhanced oil degradation, although less than the other treatments. Analysis of the dominant species in the microcosms after 12 weeks, using temporal temperature gradient gel electrophoresis, showed Pseudomonas species to be the dominant soil bacteria in both bioaugmented and biostimulated microcosms.


CONCLUSIONS
Addition of water and nutrients may enhance oil degradation through the biostimulation of indigenous oil-degrading microbial populations within the soil. However, bioaugmentation with Antarctic bacteria capable of efficient low temperature hydrocarbon degradation may enhance the rate of bioremediation if applied soon after the spill.


CONCLUSIONS
In the future, native soil bacteria could be of use in bioremediation technologies in Antarctica.
Stallwood
B
B
School of Biological Sciences, University of Wales, Bangor, Wales, UK.
Shears
J
J
Williams
P A
PA
Hughes
K A
KA
D000473:Alkanes / Q000378:metabolism; D000864:Antarctic Regions; D003080:Cold Temperature; D015169:Colony Count, Microbial / Q000379:methods; D003470:Culture Media; D004269:DNA, Bacterial / Q000032:analysis; D004224:Diterpenes / Q000378:metabolism; D017753:Ecosystem; D004586:Electrophoresis / Q000379:methods; D004785:Environmental Pollutants / Q000633:toxicity*; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods; D006838:Hydrocarbons; D021141:Nucleic Acid Amplification Techniques / Q000379:methods; D010578:Petroleum / Q000633:toxicity*; D011549:Pseudomonas / Q000254:growth & development / Q000502:physiology*; D011551:Pseudomonas fluorescens / Q000254:growth & development / Q000502:physiology; D012988:Soil Microbiology; D014867:Water
D000473:Alkanes; D003470:Culture Media; D004269:DNA, Bacterial; D004224:Diterpenes; D004785:Environmental Pollutants; D006838:Hydrocarbons; D010578:Petroleum; D014867:Water; C008906:phytane