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José Julio Ortega. Instituto de Recursos Naturales y Agrobiología de Sevilla. Consejo Superior de Investigaciones Científicas. ASSESSING THE MICROBIAL AVAILABILITY OF POLYCYCLIC AROMATIC HYDROCARBONS PRESENT IN MARINE SPILLS. OBJECTIVES.
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José Julio Ortega Instituto de Recursos Naturales y Agrobiología de Sevilla Consejo Superior de Investigaciones Científicas • ASSESSING THE MICROBIAL AVAILABILITY OF POLYCYCLIC AROMATIC HYDROCARBONS PRESENT IN MARINE SPILLS
OBJECTIVES Proyect VEM 2004-08556: “Microbial availability and metabolism of polycyclic aromatic hydrocarbons present in marine oil spills. Implications for their natural attenuation and bioremediation” Examine PAH bioavailability and metabolism in different scenarios relevant to marine oil spills: water column (dispersants), shoreline (bioremediation) and sediments (nat. attenuation) OBJ. 1 Microbial physiology and metabolism of PAH biodegradation in marine microorganisms OBJ. 2 Study of physicochemical processes involved in PAH bioavailability and their modification by biological factors and spill management strategies OBJ. 3 Bioavailability and metabolism of PAH in microcosms
1 Sorbed to organic matter and clay fractions Sorbed in micropores smaller than bacteria LOW BIOAVAILABILITY (slow kinetics, residual fractions) 2 Dissolved in non-aqueous phase liquids 3 Dissolved in macropores
BIOSURFACTANT PRODUCTION
CMC Effect of Pseudomonas aeruginosa 19SJ biosurfactants on surface tension: critical micelle concentration
Growth and biosurfactant production by Pseudomonas aeruginosa 19SJ from solid phenanthrene (10 mg/ml) M. Garcia-Junco et al., Environ. Microbiol.2001, 3, 561-569
Effect of biosurfactants from Pseudomonas aeruginosa 19SJ on partitioning of pyrene from a NAPL Ceqsolids Biosurf. Solids Ceq Part. rate (ng/mL/h) (µg/mL) (mg/mL) (ng/mL) (ng/mg) 0 0 0 1 1 0,5 1,6 11,6 0,7 27,4 18 85 547 27 650 - - - 16 40 0 10 100 0 100 M. Garcia-Junco et al., Environ. Sci. Technol.2003, 37, 2988-2996
Capillary tube 1mL CHEMOTAXISCAPILLARY METHOD Chemoattractant or control slide coverslip Bacterial suspension
Chemotaxis towards phenanthrene of Pseudomonasputida 10D J.J. Ortega-Calvo et al., FEMS Microbiol. Ecol.2003, 44, 373-381
Environmental sample DESORPTION BIODEGRADATION TENAX SAMPLE SUSPENSION NaOH TRAP SAMPLE SUSPENSION - TENAX EXTRACTION - HPLC ANALYSIS - MC EXTRACTION - HPLC ANALYSIS (native PAH) - 14CO2 MEASUREMENTS (14C-PAH)
Teflon-lined stoppers Syringe sampling A. 14CO2 production B. HPLC analysis Biometric flask 250 ml erlenmeyer flask Main body Teflon-lined stopper Lateral body 14CO2 40 g Sample 40 g sample + radiolabelled PAH Alkali trap BIOAVAILABILITY ASSAY
DESORPTION OF PAHs WITH TENAX CREOSOTE-POLLUTED SOIL Fen Flu Flut Ant St / S0 = Frap * exp (-Krap * t) + Fslow * exp (-Kslow * t) Pyr Benz(a)pyr
DESORPTION OF PAHs WITH TENAX BIOREMEDIATED SOIL Fen Ant Fluor Pyr St / S0 = Frap * exp (-Krap * t) + Fslow * exp (-Kslow * t) Benz(a)pyr Benz(a)ant
BIOAVAILABILITY OF PAH IN BIOREMEDIATED SOIL (SOILREM E6068) (0.2 g/Kg PAH) Pir Ftno Fen
Background PAH pollution in Gibraltar Area (Cádiz) (µg/kg 16 EPA PAH) 346 142 404 85 42 186 98 222 429 166 118 1250 111 55 124 59 372 1366 GIBRALTAR SAMPLING POINTS ROADS URBAN ZONES INDUSTRIAL ZONES
Phenanthrene content in soils from Gibraltar Area *Wild, S.R. & Jones, K.C., Environ. Pollut.1995, 88, 91-108
14C native • Conditions: • 40 g soil amended with 11.8 µg/kg 14C-phen dissolved in distilled water Bioaccessibility of native phenanthrene to autochtonous microbial populations in soils with different % OM
CONCLUSIONS 1. FAR FROM BEHAVING AS PASSIVE CATALISTS, MICROORGANISMS INHABITING PAH-POLLUTED SOILS AND SEDIMENTS CAN SOLVE A RANGE OF LOW-BIOAVAILABILITY SITUATIONS BY IMPROVING THEIR MODES OF POLLUTANT ACQUISITION (BIOSURFACTANTS, CHEMOTAXIS, ETC.) 2. HOWEVER, THERE ARE A NUMBER OF ENVIRONMENTAL SITUATIONS, FOR EXAMPLE INVOLVING DESORPTION-RESISTANT COMPOUNDS, WHERE THE PHYSICAL CONSTRAINTS FOR BIODEGRADATION ARE HARDLY MODIFIABLE BY PHYSIOLOGICAL MEANS
Grupo “Biodegradación y Biorremediación” (PAI-RNM312) Instituto de Recursos Naturales y Agrobiología de Sevilla C.S.I.C. Marisa Bueno Marta García-Junco* César Gómez* Mohammed Lahlou* Jose Luis Niqui Rosa Posada Patricia Velasco José Julio Ortega M. Grifoll (Univ. Barcelona) Hauke Harms (UFZ, Leipzig) Anatoly Marchenko (R. Center Toxicol., Rusia)