Data/hora: 21/09/2024 12:18:58

Biblioteca(s): 	Embrapa Gado de Leite.	
Data corrente: 	02/04/2015	
Data da última atualização: 	05/02/2024	
Autoria: 	POLONINI, H. C.; BRANDAO, H. de M.; RAPOSO, N. R. B.; MOUTON, L.; YÉPRÉMIAN, C.; COUTÉ, A.; BRAYNER, R.	
Afiliação: 	HUDSON C. POLONINI, UFJF; HUMBERTO DE MELLO BRANDAO, CNPGL; NÁDIA R. B. RAPOSO, UFJF; LUDOVIC MOUTON, Université Paris Diderot, Paris; CLAUDE YÉPRÉMIAN, Muséum National d'Histoire Naturelle, Paris; ALAIN COUTÉ, Muséum National d'Histoire Naturelle, Paris; ROBERTA BRAYNER, Université Paris Diderot, Paris.	
Título: 	Ecotoxicological studies of micro- and nanosized barium titanate on aquatic photosynthetic microorganisms.	
Ano de publicação: 	2014	
Fonte/Imprenta: 	Aquatic Toxicology, v. 154, p. 58-70, 2014.	
DOI: 	https://doi.org/10.1016/j.aquatox.2014.05.005	
Idioma: 	Inglês	
Conteúdo: 	The interaction between live organisms and micro- or nanosized materials has become a current focus in toxicology. As nanosized barium titanate has gained momentum lately in the medical field, the aims of the present work are: (i) to assess BT toxicity and its mechanisms on the aquatic environment, using two photosynthetic organisms (Anabaena flos-aquae, a colonial cyanobacteria, and Euglena gracilis, a flagellated euglenoid); (ii) to study and correlate the physicochemical properties of BT with its toxic profile; (iii) to compare the BT behavior (and Ba2+ released ions) and the toxic profile in synthetic (Bold's Basal, BB, or Mineral Medium, MM) and natural culture media (Seine River Water, SRW); and (iv) to address whether size (micro, BT MP, or nano, BT NP) is an issue in BT particles toxicity. Responses such as growth inhibition, cell viability, superoxide dismutase (SOD) activity, adenosine-5-triphosphate (ATP) content and photosynthetic efficiency were evaluated. The main conclusions are: (i) BT have statistically significant toxic effects on E. gracilis growth and viability even in small concentrations (1 μg mL−1), for both media and since the first 24 h; on the contrary of on A. flos-aquae, to whom the effects were noticeable only for the higher concentrations (after 96 h: ≥75 μg mL−1 for BT NP and =100 μg mL−1 for BT MP, in BB; and ≥75 μg mL−1 for both materials in SRW), in spite of the viability being affected in all concentrations; (ii) the BT behaviors in synthetic and natural culture media were slightly different, being the toxic effects more pronounced when grown in SRW – in this case, a worse physiological state of the organisms in SRW can occur and account for the lower resistance, probably linked to a paucity of nutrients or even a synergistic effect with a contaminant from the river; and (iii) the effects seem to be mediated by induced stress without a direct contact in A. flos-aquae and by direct endocytosis in E. gracilis, but in both organisms the contact with both BT MP and BT NP increased SOD activity and decreased photosynthetic efficiency and intracellular ATP content; and (iv) size does not seem to be an issue in BT particles toxicity since micro- and nano-particles produced significant toxic for the model-organisms.	
Thesaurus Nal: 	barium titanate; ecotoxicology; nanoparticles.	
Categoria do assunto: 	X Pesquisa, Tecnologia e Engenharia	
Registro original: 	Embrapa Gado de Leite (CNPGL)	
Exemplares: 	CNPGL - (21801-1) - UPC - AP - DD -  -  -  - DIS