HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Figures Only Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in ISI Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via ISI Web of Science (19) Citing Articles via Google Scholar Google Scholar Articles by Miya, R. K. Articles by Firestone, M. K. Search for Related Content PubMed PubMed Citation Articles by Miya, R. K. Articles by Firestone, M. K. GeoRef GeoRef Citation Agricola Articles by Miya, R. K. Articles by Firestone, M. K. Related Collections Soil Microbiology Bioremediation and Biodegradation Organic Compounds Plant and Environment Interactions

TECHNICAL REPORT
Bioremediation and Biodegradation

Enhanced Phenanthrene Biodegradation in Soil by Slender Oat Root Exudates and Root Debris

Department of Environmental Science, Policy, and Management, Ecosystem Sciences Div., 151 Hilgard Hall no. 3110, Univ. of California, Berkeley, CA 94720-3110

* Corresponding author (mkfstone{at}nature.berkeley.edu)

Received for publication August 17, 2000. To investigate the mechanisms by which slender oat (Avena barbata Pott ex Link) enhances phenanthrene biodegradation, we analyzed the impacts of root exudates and root debris on phenanthrene biodegradation and degrader community dynamics. Accelerated phenanthrene biodegradation rates occurred in soils amended with slender oat root exudates as well as combined root debris + root exudate as compared with unamended controls. Root exudates significantly enhanced phenanthrene biodegradation in rhizosphere soils, either by increasing contaminant bioavailability and/or increasing microbial population size and activity. A modified most probable number (MPN) method was used to determine quantitative shifts in heterotrophic and phenanthrene degrader communities. During the first 4 to 6 d of treatment, heterotrophic populations increased in all amended soils. Both root debris–amended and exudate-amended soil then maintained larger phenanthrene degrader populations than in control soils later in the experiment after much of the phenanthrene had been utilized. Thus, root amendments had a greater impact over time on phenanthrene degraders than heterotrophs resulting in selective maintenance of degrader populations in amended soils compared with controls.

Abbreviations: MPN, most probable number • PAH, polycyclic aromatic hydrocarbon • TOC, total organic carbon • TSB, trypticase soy broth • HPLC, high performance liquid chromatography • GC-FID, gas chromatography–flame ionization detector

This article has been cited by other articles:

				Z. D. Parrish, M. K. Banks, and A. P. Schwab Effect of Root Death and Decay on Dissipation of Polycyclic Aromatic Hydrocarbons in the Rhizosphere of Yellow Sweet Clover and Tall Fescue J. Environ. Qual., January 1, 2005; 34(1): 207 - 216. [Abstract] [Full Text] [PDF]