title: Occurrence of 4-tert-butylphenol (4-t-BP) biodegradation in an aquatic sample caused by the presence of Spirodela polyrrhiza and isolation of a 4-t-BP-utilizing bacterium.
abstract: Although 4-tert-butylphenol (4-t-BP) is a serious aquatic pollutant, its biodegradation in aquatic environments has not been well documented. In this study, 4-t-BP was obviously and repeatedly removed from water from four different environments in the presence of Spirodela polyrrhiza, giant duckweed, but 4-t-BP persisted in the environmental waters in the absence of S. polyrrhiza. Also, 4-t-BP was not removed from autoclaved pond water with sterilized S. polyrrhiza. These results suggest that the 4-t-BP removal from the environmental waters was caused by biodegradation stimulated by the presence of S. polyrrhiza rather than by uptake by the plant. Moreover, Sphingobium fuliginis OMI capable of utilizing 4-t-BP as a sole carbon and energy source was isolated from the S. polyrrhiza rhizosphere. Strain OMI degraded 4-t-BP via a meta-cleavage pathway, and also degraded a broad range of alkylphenols with linear or branched alkyl side chains containing two to nine carbon atoms. Root exudates of S. polyrrhiza stimulated 4-t-BP degradation and cell growth of strain OMI. Thus, the stimulating effects of S. polyrrhiza root exudates on 4-t-BP-degrading bacteria might have contributed to 4-t-BP removal in the environmental waters with S. polyrrhiza. These results demonstrate that the S. polyrrhiza-bacteria association may be applicable to the removal of highly persistent 4-t-BP from wastewaters or polluted aquatic environments.
authors: Division of Sustainable Energy and Environmental Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka, 565-0871, Japan. ogata@wb.see.eng.osaka-u.ac.jp
authors: Yuka
authors: Y
authors: Ogata
authors: Tadashi
authors: T
authors: Toyama
authors: Ning
authors: N
authors: Yu
authors: Xuan
authors: X
authors: Wang
authors: Kazunari
authors: K
authors: Sei
authors: Michihiko
authors: M
authors: Ike
mesh_terms: D001419:Bacteria / Q000378:metabolism; D001673:Biodegradation, Environmental; D010636:Phenols / Q000378:metabolism*; D042301:Sphingomonadaceae / Q000378:metabolism*
chemical_list: D010636:Phenols; C006862:butylphen