Effect of humic fractions and clay on biodegradation of phenanthrene by a Pseudomonas fluorescens strain isolated from soil.
The mineralization of phenanthrene in pure cultures of a Pseudomonas fluorescens strain, isolated from soil, was measured in the presence of soil humic fractions and montmorillonite. Humic acid and clay, either separately or in combination, shortened the acclimation phase. A higher mineralization rate was measured in treatments with humic acid at 100 microg/ml. Humic acid at 10 microg/ml stimulated the transformation only in the presence of 10 g of clay per liter. We suggest that sorption of phenanthrene to these soil components may result in a higher concentration of substrate in the vicinity of the bacterial cells and therefore may increase its bioavailability.
Ortega-Calvo
J J
JJ
Instituto de Recursos Naturales y Agrobiologia, C.S.I.C., Apartado 1052, 41080 Seville, Spain. jjortega@irnase.scic.es
Saiz-Jimenez
C
C
D000538:Aluminum Silicates / Q000494:pharmacology*; D001546:Bentonite / Q000494:pharmacology; D001673:Biodegradation, Environmental; D000077215:Clay; D006812:Humic Substances / Q000494:pharmacology*; D010616:Phenanthrenes / Q000378:metabolism*; D011551:Pseudomonas fluorescens / Q000378:metabolism*; D012988:Soil Microbiology
D000538:Aluminum Silicates; D006812:Humic Substances; D010616:Phenanthrenes; D001546:Bentonite; C031181:phenanthrene; D000077215:Clay