title: Effect of citric acid and bacteria on metal uptake in reeds grown in a synthetic acid mine drainage solution.
abstract: The effect of citric acid (CA), rhizosphere acidophilic heterotrophs and/or Fe(II) oxidizing bacteria (Fe(II)OB) on plaque formation and metal accumulation in Phragmites australis L. (common reed) from acid mine drainage (AMD) solution were investigated. Reeds were grown in different hydroponic solutions that contained AMD, CA and/or rhizosphere bacteria for three months. Triplicate experiments were conducted for each experimental condition. Fe(II)OB enhanced the formation of Fe plaque which decreased Fe and Mn uptake in reeds, while it had no significant influence on Al accumulation. CA inhibited the growth of Fe(II)OB, decreased the formation of metal plaque and increased Fe and Mn accumulation in reeds. Acidophilic heterotrophs consumed CA and made the environment more suitable for the growth of Fe(II)OB. Reeds are a good candidate for phytoextraction while CA is a useful chelator to enhance metal uptake in plants. More research may be needed to investigate the influence of CA on microbial community. Further investigations are required to study the effect of CA on phytoremediation of AMD contaminated fields.
authors.affiliation: Department of Biological & Environmental Sciences, Texas A&M University-Commerce, Commerce, TX 75429-3011, USA. Electronic address: Lin.Guo@tamuc.edu.
authors.forename: Lin
authors.initials: L
authors.lastname: Guo
authors.affiliation: Auburn Science and Engineering Center (ASEC) 215, Department of Civil Engineering, The University of Akron, OH 44325-3905, USA. Electronic address: tcutrig@uakron.edu.
authors.forename: Teresa J
authors.initials: TJ
authors.lastname: Cutright
mesh_terms: D001419:Bacteria / Q000378:metabolism*; D018407:Bacterial Physiological Phenomena; D001673:Biodegradation, Environmental; D019343:Citric Acid / Q000494:pharmacology*; D006801:Humans; D019216:Metals, Heavy / Q000378:metabolism*; D008906:Mining; D018517:Plant Roots / Q000382:microbiology; D006109:Poaceae / Q000187:drug effects / Q000378:metabolism*; D058441:Rhizosphere
chemical_list: D019216:Metals, Heavy; D019343:Citric Acid
keywords: Acidophilic heterotrophs; Citric acid; Hydroponic conditions; Iron oxidizing bacteria; Phragmites australis