title: Demulsifying properties of extracellular products and cells of Pseudomonas aeruginosa MSJ isolated from petroleum-contaminated soil.
abstract: A strain of Pseudomonas aeruginosa isolated from a site contaminated with refined oil products exhibited demulsification capabilities against Tween 80-Span 80 stabilized oil-in-water (O/W), Tween 80-stabilized water-in-oil (W/O) model emulsions (kerosene-water), and an industrial emulsion (Daido Dairoll PA-5A). GC-MS analysis confirmed the presence of fatty acids and carbohydrates in the extracellular biodemulsifier. The demulsifying activity of cells and culture supernatants was favored by growth in media containing 1% diesel oil. There was a correlation between culture age, de-emulsification and cellular hydrophobicity, and highest activities were observed for cells and supernatants from 96-h cultures. Activity increased with addition of up to 60 mg cells or 300 μL supernatant to emulsions. The activity was relatively stable at 20-40 °C and to freezing, but was reduced by 69% by washing the cells with chloroform-methanol-water. This demulsifier has potential for application in biotreatment of emulsified oily wastewaters to promote recovery and/or degradation of oil.
authors.affiliation: Departamento de Microbiologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, CP 486, 31270-901 Belo Horizonte, MG, Brazil.
authors.forename: J O P A
authors.initials: JO
authors.lastname: Coutinho
authors.forename: M P S
authors.initials: MP
authors.lastname: Silva
authors.forename: P M
authors.initials: PM
authors.lastname: Moraes
authors.forename: A S
authors.initials: AS
authors.lastname: Monteiro
authors.forename: J C C
authors.initials: JC
authors.lastname: Barcelos
authors.forename: E P
authors.initials: EP
authors.lastname: Siqueira
authors.forename: V L
authors.initials: VL
authors.lastname: Santos
mesh_terms: D001673:Biodegradation, Environmental; D004655:Emulsions / Q000737:chemistry / Q000378:metabolism; D007219:Industrial Oils / Q000382:microbiology*; D011550:Pseudomonas aeruginosa / Q000145:classification / Q000378:metabolism*; D012988:Soil Microbiology; D012989:Soil Pollutants / Q000737:chemistry* / Q000302:isolation & purification*; D013045:Species Specificity
chemical_list: D004655:Emulsions; D012989:Soil Pollutants