Dissertações em Biologia Ambiental (Mestrado) - PPBA/IECOS
URI Permanente para esta coleçãohttps://repositorio.ufpa.br/handle/2011/2607
O Mestrado em Biologia Ambiental foi criado em 1999 e implementado em 2000 e funciona no Programa de Pós-Graduação em Biologia Ambiental (PPBA) do Instituto de Estudos Costeiros (IECOS) localizado no Campus Universitário de Bragança da Universidade Federal do Pará (UFPA).
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Item Acesso aberto (Open Access) Resistência e bioacumulação de arsênio na cianobactéria Phormidium sp(Universidade Federal do Pará, 2012-07-31) FERREIRA, Anna Rafaella dos Santos; SCHNEIDER, Maria Paula Cruz; http://lattes.cnpq.br/3901112943859155Environmental contamination by arsenic has been increasing in recent years, either through natural or anthropogenic sources, which can cause greater exposure of humans to this toxic compound. Several studies have been developed to analyze the capacity of cyanobacterial species in bioremediation. The filamentous cyanobacterium Phormidium sp. excels due to well developed mechanisms to adapt to different environmental conditions. The present study aimed to analyze the resistance profile of Phormidium sp. at different concentrations of sodium arsenate. The cyanobacterium was inoculated in tubes containing 4 ml of BG-11 liquid medium and different concentrations of arsenate (5, 10, 30, 50, 100, 130, 150, 200 and 250 mM) without the presence of metalloid (control) and cultured for 20 days at 25 ° C without agitation and with a photoperiod of 12/12 h light / dark. The toxicity of arsenate to Phormidium sp. has been characterized by growth inhibition being determined by the concentration of chlorophyll a. All conditions were performed in triplicate. The determination of total arsenic in the samples was obtained using the technique of optical emission spectrometry with inductively coupled plasma, the Instituto Evandro Chagas. The resistance of Phormidium sp. to arsenate was observed up to 50 mM of compound (p>0.05). Growth inhibition was observed above 100mM of arsenate (p<0.05). The analyzes of the total dose of arsenic in the culture medium showed that during the first day of experiment, the concentration of arsenic in the culture medium was lowered, followed by a gradual increase in the concentration of this metalloid. Probably, this cyanobacteria can accumulate arsenic and later excrete this metalloid to the extracellular medium. The results indicate the ability of the cyanobacterium Phormidium sp. has to grow in medium containing high concentrations of arsenic. However, other analyzes become fundamental for elucidating the metabolic pathways involved in the process of resistance to this metalloid.