Characterization of desmodesmus pleiomorphus isolated from a heavy metal-contam...

• Author(s): Monteiro, Cristina M. ; Marques, Ana P. G. C. ; Castro, Paula M. L. ; Malcata, F. Xavier
• Date: 2009
• Persistent ID: http://hdl.handle.net/10400.14/3261
• Origin: Veritati - Repositório Institucional da Universidade Católica Portuguesa
• Subject(s): Microalgae; Accumulation; Bioremediation; pH; Metal uptake
• Document Type: Article
• Language: English

Description

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 Zn2? 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 Zn2? 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.