Hairy Roots of Helianthus annuus: A Model System to Study Phytoremediation of Tetracycline and Oxytetracycline

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• 作者：Ninad P. Gujarathi ; Bryan J. Haney ; Heidi J. Park ; S. Ranil Wickramasinghe ; and James C. Linden
• 刊名：Biotechnology Progress
• 出版年：2005
• 出版时间：June 2005
• 年：2005
• 卷：21
• 期：3
• 页码：775 - 780
• 全文大小：118K
• 年卷期：v.21,no.3(June 2005)
• ISSN：1520-6033

文摘

The release of antibiotics to the environment has to be controlled because of seriousthreats to human health. Hairy root cultures of Helianthus annuus (sunflower), alongwith their inherent rhizospheric activity, provide a fast growing, microbe-freeenvironment for understanding plant-pollutant interactions. The root system catalyzesrapid disappearance of tetracycline (TC) and oxytetracycline (OTC) from aqueousmedia, which suggests roots have potential for phytoremediation of the two antibioticsin vivo. In addition, in vitro modifications of the two antibiotics by filtered, cell- andmicrobe-free root exudates suggest involvement of root-secreted compounds. Themodification is confirmed from changes observed in UV spectra of exudate-treatedOTC. Modification appears to be more dominant at the BCD chromophore of theantibiotic molecule. Kinetic analyses dismiss direct enzyme catalysis; the modificationrates decrease with increasing OTC concentrations. The rates increase with increasingage of cultures from which root exudates are prepared. The decrease in modificationrates upon addition of the antioxidant ascorbic acid (AA) suggests involvement ofreactive oxygen species (ROS) in the antibiotic modification process.