Navegando por Assunto "Algas"

Agora exibindo 1 - 2 de 2

Acesso aberto (Open Access)
Diversidade e abundância de algas epilíticas no setor do médio Rio Xingu-PA
(Universidade Federal do Pará, 2010-08-31) BASTOS, Alessandra dos Santos Matni; CAMARGO-ZORRO, Mauricio; http://lattes.cnpq.br/5423657235023988
The periphyton is defined as a complex community of microorganisms (fungi, algae, bacteria, animals), which along with organic and inorganic particles is loosely or firmly adhered to a substrate submerged. Epilithic algae (bedrock) are organims found in environments of rivers and rapids, and other ecosystems. This paper aims to list the diversity of epilithic algae, estimate their relative abundance and frequency of occurrence during an annual cycle. In the main channel of the river Xingu was selected environment rapids of Boa Esperança and localities Arroz Cru. The epilíton was removed, properly identified and preserved in Transeau solution and subsequently analyzed in the laboratory. Were listed 132 species belonging to 78 genera. The total richness observed for Boa Esperança and Arroz Cru, in the months studied were 108 and 101 species respectively. Among all classes, Bacillariophyceae expressed greater contribution in both localities in terms of richness and abundance. The epilithic specie more abundant was Aulacoseira granulata (Ehrenberg) Simonsen (Bacillariophyceae), in the locations studied. In november/2006 and january/2007 (flood) occurred at higher densities mean: 133 and 124 ind.cm-2 in the riverine environment Boa Esperança. In the Arroz Cru was 107 and 90 ind.cm-2. The lowest mean density occurred in march/2007 (filled) with 26 ind.cm-2 in the riverine environment and Boa Esperança in august 2006 (flood) with 15 ind.cm-2 in Arroz Cru. The diversity of epilíton varied among seasons. The precipitation, wind, turbidity and nutrients, possibly influence the variations of abundance, richness and density.
Acesso aberto (Open Access)
Ocorrência de inibidores de glicosidases em cianobactérias e microalgas dos estados do Amapá e Tocantins
(Universidade Federal do Pará, 2015-08-13) SILVA, Vivian Cassia Oliveira da; XAVIER, Luciana Pereira; http://lattes.cnpq.br/6207860145204571
Cyanobacteria are presented as a new source of secondary metabolites for the production of bio-products in many industrial sectors and are used primarily because of its easy cultivation, using few nutritional sources, as well as a large biomass production. Until now we don't have many report in literature of cyanobacteria from amazon, as well as their metabolites and their use in bioproducts. Glycosidases are enzymes of extreme importance as targets for developing drugs that are used for the treatment of various diseases, as well as their inhibitors. This study aimed to identify 24 samples of cyanobacteria and microalgae from the states of Tocantins and Amapá, isolates that produce these inhibitors, as well as extract, fractionate and identify them. Initially, the detection test in petri dishes with esculin the substrate for glycosidase inhibitors has been standardized and the extraction methodology. As a result there was glucosidase inhibitory activity of crude extract and the methanol fraction of four samples (Synechococcus sp, Monoraphydium, P29 and Limnotrix sp), inhibitory activity was detected in the aqueous fractions of any culture. Two methanolic fractions that showed activity was selected for potential assay conducting inhibiting α-glycosidase face with the substrate p-nitrophenyl α-D-glucopyranoside and β-glucosidase to the substrate p-nitrophenyl β-D-glucopyranoside, where both samples had a higher percentage of inhibition for α-glucosidase compared to β-glucosidase.