Stimulation and Molecular Characterization of Bacterial Perchlorate Degradation by Plant-Produced Electron Donors

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• 作者：Joshua D. Shrout ; Garrett C. Struckhoff ; Gene F. Parkin ; and Jerald L. Schnoor
• 刊名：Environmental Science & Technology
• 出版年：2006
• 出版时间：January 1, 2006
• 年：2006
• 卷：40
• 期：1
• 页码：310 - 317
• 全文大小：268K
• 年卷期：v.40,no.1(January 1, 2006)
• ISSN：1520-5851

文摘

Root homogenate from poplar trees (Populus deltoides ×nigra DN34, Imperial Carolina) stimulated perchloratedegradation in microcosms of soil and water samplescollected at a perchlorate contaminated site, the LonghornArmy Ammunition Plant (LHAAP), located outside Karnack,Texas. Direct use of root products by perchlorate-degrading bacteria was shown for the first time as six pure-culture bacteria isolated from LHAAP perchlorate-degrading microcosms degraded perchlorate when givenroot products as the sole exogenous source of carbon andelectron donor. Nonenriched environmental consortiawere able to utilize root products for perchlorate degradation,regardless of prior exposure to perchlorate. Microcosmsthat contained perchlorate-contaminated groundwater(MW-3) or uncontaminated surface water (Harrison Bayou)as inoculum degraded approximately 240 and 160 mg L^-1perchlorate, respectively, using root products (approximately440 mg L^-1 as COD) over 38 days. The predominantbacterial species in these aqueous microcosms, identifiedby DGGE, depended only upon the source inoculum assimilar sequences were obtained whether root productsor lactate was the electron donor. Sequences from DGGEbands that matched species within Dechloromonas, agenus consisting of many perchlorate degraders, wereidentified in all perchlorate-degrading microcosms. Thisstudy demonstrates the ability of root products to driveperchlorate respiration by bacteria and the potentialfor successful achievement of perchlorate rhizodegradationusing in situ phytoremediation.