Study of a bacterial consortium adapted to low bioavailability to phenanthrene, as potential inoculant to chronically PAH contaminated soils.

LOPEZ A.M.; MEDINA R.; BOSCH M.A.; YANTORNO O.; DEL PANNO M.T.

Barcelona

Congreso; 12th International UFZ-Deltares Conference on Groundwater-Soil-Systems and Water Resource Management; 2013

Helmholtz Centre for Environmental Research ? UFZ 2013

The predominant bacterial strains from a degrader consortium adapted to low bioavailability to phenanthrene were studied applying conventional biochemical and physiologycal analysis and the FT-IR methology. The four isolated strains were identified as belonging to Sphingobium, Acidovorax, Rhodococcus and Arthrobacter genera, suggesting the strains could develope different strategies to integrate the phenanthrene degrader consortium. Interesting properties of each strain were detected, as phenanthrene degrading capacity in pure culture; ability to produce and accumulate a significant amount of reserve material like as PHB or TAG; abundant extracellular polysaccharide production; siderophore production and phosphorus solubilization and capacity to adherence to hydrophobic surfaces. The strains Acidovorax avenae C2 and Rhodococcus opacus C3 could not degrade phenanthrene in pure culture, regardless whether the PAH was provided as cristals or adsorbed to XAD2. When the strains were cultured toghether in the defined consortium with the phenanthrene adsorbed to XAD2, the degrader capacity was significantly higher than in the pure culture of its constituent members. This suggests the consortium growth in the biofilm increased the phenanthrene degrading capacity and promoted the individual strains growth. This synergic relationship between the strains, possible due to growth factors or metabolic intermediates, could explain the higher phenanthrene-removal efficiency of the consortium, with no significant intermediates accumulation.