Martinez-Rosales C.,Institute Clemente Estable |
Martinez-Rosales C.,University of the Republic of Uruguay |
Castro-Sowinski S.,Institute Clemente Estable |
Castro-Sowinski S.,University of the Republic of Uruguay
Polar Research | Year: 2011
We report the isolation and identification of bacteria that produce extracellular cold-active proteases, obtained from water samples collected near the Uruguayan Antarctic Base on King George Island, South Shetlands. The bacteria belonged to the genera Pseudomonas (growth between 4 and 30 °C) and Flavobacterium (growth between 4 and 18 °C). In all cases, extracellular protease production was evident when reaching the stationary phase at 18 and 4 °C but was not detected at 30 °C. The zymogram revealed the secretion of one extracellular protease per isolate, each with different relative electrophoretic mobility. The extracellular proteases produced at 4 °C showed thermal activity and stability at 30 °C. Both activity and stability at a temperature higher that 10 °C have no physiological meaning because the isolates do not experience such temperatures in the Antarctic environment; however, the possible ecological value of cold-active and -stable extracellular proteases is discussed. © 2011 C. Martínez-Rosales and S. Castro-Sowinski.
Herrera L.M.,University of the Republic of Uruguay |
Garcia-Lavina C.X.,University of the Republic of Uruguay |
Marizcurrena J.J.,University of the Republic of Uruguay |
Volonterio O.,University of the Republic of Uruguay |
And 3 more authors.
Polar Biology | Year: 2016
The oligochaete Grania sp. is a common inhabitant of Artigas Beach at Maxwell Bay (King George Island, South Shetland Islands, Maritime Antarctica) that proliferate during the summer season and feed on debris of red and brown algae. This investigation was undertaken to test the hypothesis that Grania sp. has an enzyme-producing microbiota that may facilitate the worm’s nutrient uptake by processing or metabolizing macroalgae compounds. A culture-based approach was used to investigate the occurrence of microorganisms able to degrade proteins, lipids and polysaccharides. Thirty-four hydrolytic enzyme-producing microorganisms associated with these worms, including bacteria and yeasts, were isolated and identified by sequencing a partial fragment of the 16S and 26S rDNA genes, respectively. These microorganisms have the ability to produce extracellular proteases, esterases, amylases, cellulases and agarases. The microbial genera found during this work (Flavobacterium, Pseudomonas, Salinibacterium, Psychrobacter, Cystobasidium and Rhodotorula) have been previously described in association with red and brown Antarctic algae. Our results suggest that this microbiome has a digestive capability that may assist Grania sp. in metabolizing nutrients from algae, leading us to consider the possibility of a mutualistic relationship between them. The association between the worm Grania sp. and a cold-active hydrolyzing microbiota may contribute to the macroalgae decomposition and nutrient recycling in the Antarctic ecosystem. © 2016 Springer-Verlag Berlin Heidelberg
Achyrocline satureioides (Lam.) DC. (marcela) reduces brain damage in permanent focal ischemia in rats [Achyrocline satureioides (Lam.) DC. (marcela) reduce el daño cerebral en la isquemia focal permanente en ratas]
Rivera Megret F.,Institute Clemente Estable |
Rivera Megret F.,University of the Republic of Uruguay |
Tejera Correa D.,Institute Clemente Estable |
Tejera Correa D.,University of the Republic of Uruguay |
And 5 more authors.
Revista Cubana de Plantas Medicinales | Year: 2013
Introduction: Achyrocline satureioides is a plant which has been widely used in popular medicine and experimental studies confirm its antioxidant and anti-inflammatory effects, attributable to the presence of flavonoids, mainly quercetin. Objectives: to evaluate the neuroprotective effects of a chronic oral preadministration to rats with an Achyrocline satureioides decoction (2 %). Methods: for decoction, dried flowers of Achyrocline satureioides were used. The consumption of food and AS decoction/water of the rats was evaluated daily and weight gain weekly; quercetin content in the decoction and in the plasma of the rats was evaluated by high performance liquid chromatography. The cerebral damage was assessed with a tetrazolium salt (TTC) and a behavioral test was performed previously. Nissl staining and Fluoro-Jade histochemistry were used. Results: the pre-treatment with Achyrocline satureioides in all groups reverted the functional deficit and, during 21 days, the infarction volume also decreased significantly. Nissl staining showed a higher percentage of preserved neuronal population and the Fluoro-Jade showed a decreased of the neurons in degeneration. Conclusions: the quercetin levels in the decoction and plasma of rats could explain the preventive benefits of Achyrocline satureioides due to the antioxidant and antiinflammatory properties described for this flavonoid.