title: Liposomes enhance bioremediation of oil-contaminated soil.
abstract: Liposomes (composed of soy phosphatides) in the form of small unilamellar vesicles (SUV), when added to soil contaminated by crude oil, accelerate bioremediation. After three weeks incubation at 30 degrees C, using soil experimentally contaminated (with 10,000 ppm crude oil), level of bioremediation increased from 40% without SUV to 75% with SUV (0.1 wt% phospholipids per dry weight soil). Similarly, for accidentally contaminated soil (with approximately 17,000 ppm crude oil), addition of 0.1 wt% SUV to the soil increased the bioremediation level from 55 to 80%. The enhancing effect of liposomes is explained by two interrelated phenomena: a large increase both in total bacteria number and in diversity of bacterial species in the soil. Comparison after four weeks revealed 21 bacterial species in the presence of liposomes (many being oil-degrading bacterial species) and only nine species in the absence of liposomes. Both effects may be related to the physical effects of liposome phospholipids, which modify the crude oil by wetting it, thereby making it more accessible to the microorganisms. In addition, liposome phospholipids serve as phosphate and nitrogen sources for the bacteria.
authors.affiliation: Department of Clinical Microbiology, The Hebrew University-Hadassah Medical School, Jerusalem, Israel.
authors.forename: Ayelet
authors.initials: A
authors.lastname: Barenholz
authors.forename: Fanny
authors.initials: F
authors.lastname: Fishel
authors.forename: Elisheva
authors.initials: E
authors.lastname: Yakir
authors.forename: Shimon
authors.initials: S
authors.lastname: Gatt
authors.forename: Yechezekel
authors.initials: Y
authors.lastname: Barenholz
authors.forename: Hervé
authors.initials: H
authors.lastname: Bercovier
mesh_terms: D001419:Bacteria / Q000254:growth & development / Q000378:metabolism; D001673:Biodegradation, Environmental; D008081:Liposomes / Q000737:chemistry*; D010578:Petroleum; D012988:Soil Microbiology; D012989:Soil Pollutants
chemical_list: D008081:Liposomes; D010578:Petroleum; D012989:Soil Pollutants