title: Acceleration of nonylphenol and 4-tert-octylphenol degradation in sediment by Phragmites australis and associated rhizosphere bacteria.
abstract: We investigated biodegradation of technical nonylphenol (tNP) in Phragmites australis rhizosphere sediment by conducting degradation experiments using sediments spiked with tNP. Accelerated tNP removal was observed in P. australis rhizosphere sediment, whereas tNP persisted in unvegetated sediment without plants and in autoclaved sediment with sterile plants, suggesting that the accelerated tNP removal resulted largely from tNP biodegradation by rhizosphere bacteria. Three bacterial strains, Stenotrophomonas sp. strain IT-1 and Sphingobium spp. strains IT-4 and IT-5, isolated from the rhizosphere were capable of utilizing tNP and 4-tert-octylphenol as a sole carbon source via type II ipso-substitution. Oxygen from P. australis roots, by creating highly oxygenated conditions in the sediment, stimulated cell growth and the tNP-degrading activity of the three strains. Moreover, organic compounds from P. australis roots functioned as carbon and energy sources for two strains, IT-4 and IT-5, supporting cell growth and tNP-degrading activity. Thus, P. australis roots elevated the cell growth and tNP-degrading activity of the three bacterial strains, leading to accelerated tNP removal. These results demonstrate that rhizoremediation of tNP-contaminated sediments using P. australis can be an effective strategy.
authors: Department of Research, Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, Kofu, Yamanashi, Japan. ttohyama@yamanashi.ac.jp
authors: Tadashi
authors: T
authors: Toyama
authors: Manabu
authors: M
authors: Murashita
authors: Kazutaka
authors: K
authors: Kobayashi
authors: Shintaro
authors: S
authors: Kikuchi
authors: Kazunari
authors: K
authors: Sei
authors: Yasuhiro
authors: Y
authors: Tanaka
authors: Michihiko
authors: M
authors: Ike
authors: Kazuhiro
authors: K
authors: Mori
mesh_terms: D000332:Aerobiosis; D000693:Anaerobiosis; D001419:Bacteria / Q000254:growth & development / Q000302:isolation & purification / Q000378:metabolism*; D001673:Biodegradation, Environmental; D019015:Geologic Sediments / Q000737:chemistry* / Q000382:microbiology*; D010636:Phenols / Q000378:metabolism*; D010936:Plant Extracts / Q000378:metabolism; D018517:Plant Roots / Q000378:metabolism; D006109:Poaceae / Q000378:metabolism*; D058441:Rhizosphere
chemical_list: D010636:Phenols; D010936:Plant Extracts; C025256:nonylphenol; C105260:4-tert-octylphenol