title: Microbial enhancement of Cu2+ removal capacity of Eichhornia crassipes (Mart.).
abstract: Bacteria resistant to Cu2+, Ni2+ or Zn2+ were isolated from the rhizosphere of water hyacinth (Eichhornia crassipes (Mart.)) and their metal ion removal capacities (RCs) were determined. The Ni2+ and Zn2+ RCs of the respective metal ion-resistant bacteria were less than 4.1 mg g(-1), while one of the Cu2+-resistant bacteria (Strain CU-1) showed a significant high Cu2+ RC of 10.6 mg g(-1). The effect of inoculating water hyacinth with Strain CU-1 on its Cu2+ RC was further studied. Water hyacinths were treated with an antibiotic, oxytetracycline (OTC), to remove most rhizospheric bacteria of plant roots. Inoculation of Strain CU-1 increased the Cu2+ RC of the plant root by 1.91 (OTC-treated) and 1.56 (OTC-untreated) folds respectively when compared with the control. Results also showed that Strain CU-1 colonized onto the plant root and led to the increase of Cu2+ RC of the roots of water hyacinth.
authors.affiliation: Department of Biology, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong SAR, China.
authors.forename: L M
authors.initials: LM
authors.lastname: So
authors.forename: L M
authors.initials: LM
authors.lastname: Chu
authors.forename: P K
authors.initials: PK
authors.lastname: Wong
mesh_terms: D001419:Bacteria / Q000187:drug effects / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D001673:Biodegradation, Environmental; D003300:Copper / Q000737:chemistry / Q000378:metabolism*; D031806:Eichhornia / Q000378:metabolism / Q000382:microbiology*; D019216:Metals, Heavy / Q000378:metabolism; D010118:Oxytetracycline / Q000494:pharmacology; D018517:Plant Roots / Q000378:metabolism / Q000382:microbiology
chemical_list: D019216:Metals, Heavy; D003300:Copper; D010118:Oxytetracycline