'Humic Coverage Index' as a Determining Factor Governing Strain-Specific Hydrocarbon Availability to Contaminant-Degrading Bacteria in Soils
Autor: | J. Robert Paterek, Kristine Mila H. Cruz, Alexander V. Neimark, Wendy R. Sullivan, Bill W. Bogan, Peter I. Ravikovitch |
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Rok vydání: | 2003 |
Předmět: |
Biological Availability
Hexadecane complex mixtures Mycobacterium chemistry.chemical_compound Species Specificity Alkanes Soil Pollutants Environmental Chemistry Polycyclic Aromatic Hydrocarbons Humic Substances Soil Microbiology chemistry.chemical_classification Pyrenes Bacteria Environmental engineering General Chemistry Phenanthrenes Phenanthrene Biodegradation Contamination Biodegradation Environmental Hydrocarbon Gram-Negative Aerobic Rods and Cocci chemistry Environmental chemistry Soil water Pyrene Degradation (geology) |
Zdroj: | Environmental Science & Technology. 37:5168-5174 |
ISSN: | 1520-5851 0013-936X |
Popis: | We report development of a novel parameter for quantifying the amount of humic and fulvic acids per unit surface area in a particular soil. This quantity, the "humic coverage index" (HCI), provides a measurement of the relative spatial extents and/or thicknesses of the humic/fulvic overlayers in different soils, and, therefore, can be used in modeling various soils' behavior in sequestration processes in which humic materials are involved. HCI is herein applied to modeling biodegradation of aromatic and aliphatic hydrocarbons (phenanthrene, pyrene, and hexadecane) by several bacterial strains. Results indicate that, for the cases studies here, contaminant biodegradation is highest at a particular HCI and decreases if the coverage density of humic material is lower or higher than this optimum value. The HCI value at which maximal degradation was observed varied across different strains (indicating strain-specific differences in ability to degrade contaminants sorbed to humic materials) and, to a lesser extent, across different contaminants. The HCI concept is also demonstrated to be useful in explaining soil-, strain-, and contaminant-specific variations in the ability of fulvic acid supplementation to enhance contaminant biodegradation. Finally, we show that, in general, strains which are comparatively better at degrading contaminants in high-HCI soils also show enhanced contaminant mineralization in vitro in the presence of humic acids, such as when hydrocarbons are adsorbed onto these materials. |
Databáze: | OpenAIRE |
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