title: Characterization of Desmodesmus pleiomorphus isolated from a heavy metal-contaminated site: biosorption of zinc.
abstract: Microalgae have been proven efficient biological vectors for heavy metal uptake. In order to further study their biosorption potential, a strain of Desmodesmus pleiomorphus (L) was isolated from a strongly contaminated industrial site in Portugal. Under different initial Zn(2+) concentrations, metal removal by that strain reached a maximum of 360 mg Zn/g biomass after 7 days, at 30 mg Zn/l, after an initial rapid phase of uptake. Comparative studies were carried out using a strain of the same microalgal species that is commercially available (ACOI 561): when exposed to 30 mg Zn/l, it could remove only 81.8 mg Zn/g biomass. Biosorption experiments using inactivated biomass of the isolated strain reached a maximum Zn(2+) uptake of 103.7 mg/g. Metal removal at various initial pH values was studied as well; higher removal was obtained at pH 5.0. The microalga strain L, isolated from the contaminated site, exhibited a much higher removal capacity than the commercial strain, and the living biomass yielded higher levels of metal removal than its inactivated form.
authors.affiliation: Escola Superior de Biotecnologia, Universidade Católica Portuguesa, Rua Dr. António Bernardino de Almeida, 4200-072, Porto, Portugal.
authors.forename: Cristina M
authors.initials: CM
authors.lastname: Monteiro
authors.forename: Ana P G C
authors.initials: AP
authors.lastname: Marques
authors.forename: Paula M L
authors.initials: PM
authors.lastname: Castro
authors.forename: F
authors.initials: F
authors.lastname: Xavier Malcata
mesh_terms: D000042:Absorption; D000327:Adsorption; D001673:Biodegradation, Environmental; D018533:Biomass; D000460:Chlorophyta / Q000254:growth & development / Q000302:isolation & purification* / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D019216:Metals, Heavy / Q000302:isolation & purification / Q000378:metabolism*; D015032:Zinc / Q000378:metabolism*
chemical_list: D019216:Metals, Heavy; D015032:Zinc