title: Enhanced haloarchaeal oil removal in hypersaline environments via organic nitrogen fertilization and illumination.
abstract: Hypersaline soil and pond water samples were mixed with 3 % crude oil, some samples were autoclaved to serve as sterile controls; experimental samples were not sterilized. After 6-week incubation at 40 °C under light/dark cycles, the soil microflora consumed 66 %, and after 4 weeks the pond water microflora consumed 63 % of the crude oil. Soil samples treated with 3 % casaminoacids lost 89 % of their oil after 6 weeks and water samples lost 86 % after 4 weeks. Samples treated with casaminoacids and antibiotics that selectively inhibited bacteria, lost even more oil, up to 94 %. Soil-water mixtures incubated under continuous illumination lost double as much more oil than samples incubated in the dark. The soil-water mixture at time zero contained 1.3 × 10(4) CFU g(-1) of hydrocarbon-utilizing microorganisms which were affiliated to Halomonas aquamarina, Exiguobacterium aurantiacum, Haloferax sp., Salinococcus sp., Marinococcus sp. and Halomonas sp. After 6-week incubation with oil, these numbers were 8.7 × 10(7) CFU g(-1) and the Haloferax sp. proportion in the total microflora increased from 20 to 93 %. Experiments using the individual cultures and three other haloarchaea isolated earlier from the same site confirmed that casaminoacids and light enhanced their oil consumption potential in batch cultures.
authors.affiliation: Microbiology Program, Department of Biological Sciences, Faculty of Science, Kuwait University, PO Box 5969, 13060 Safat, Kuwait.
authors.forename: D M
authors.initials: DM
authors.lastname: Al-Mailem
authors.forename: M
authors.initials: M
authors.lastname: Eliyas
authors.forename: S S
authors.initials: SS
authors.lastname: Radwan
mesh_terms: D001105:Archaea / Q000254:growth & development* / Q000378:metabolism*; D001673:Biodegradation, Environmental; D009584:Nitrogen / Q000378:metabolism; D010578:Petroleum / Q000378:metabolism* / Q000382:microbiology*; D059392:Petroleum Pollution; D054712:Salinity; D012988:Soil Microbiology; D014871:Water Microbiology
chemical_list: D010578:Petroleum; D009584:Nitrogen