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Transporte ativo de a-glicosídeos por Saccharomyces cerevisiae
(Florianópolis, SC, 2012)
Mycelial glucoamylases produced by the thermophilic fungus Scytalidium thermophilum strains 15.1 and 15.8: purification and biochemical characterization
(Sociedade Brasileira de Microbiologia, 2008)
Two strains (15.1 and 15.8) of the thermophilic fungus Scytalidium thermophilum produced high levels of intracellular glucoamylases, with potential for industrial applications. The isoform I of the glucoamylase produced ...
Modelado del proceso de hidrólisis enzimática de almidones gelatinizados del fruto de la planta de banano
(2012)
Se estudió la cinética de hidrólisis enzimática del almidón de banano a glucosa. Se realizó un análisis DSC para conocer la temperatura de gelatinización de este almidón; a partir de estos resultados se evaluó del cambio ...
Feedback inhibition of starch degradation in Arabidopsis leaves mediated by trehalose 6-phosphate
(American Society of Plant Biologist, 2013-11)
Many plants accumulate substantial starch reserves in their leaves during the day and remobilize them at night to provide carbon and energy for maintenance and growth. In this paper, we explore the role of a sugar-signaling metabolite, trehalose-6-phosphate (Tre6P), in regulating the accumulation and turnover of transitory starch in Arabidopsis (Arabidopsis thaliana) leaves. Ethanol-induced overexpression of trehalose-phosphate synthase during the day increased Tre6P levels up to 11-fold. There was a transient increase in the rate of starch accumulation in the middle of the day, but this was not linked to reductive activation of ADP-glucose pyrophosphorylase. A 2- to 3-fold increase in Tre6P during the night led to significant inhibition of starch degradation. Maltose and maltotriose did not accumulate, suggesting that Tre6P affects an early step in the pathway of starch degradation in the chloroplasts. Starch granules isolated from induced plants had a higher orthophosphate content than granules from noninduced control plants, consistent either with disruption of the phosphorylation-dephosphorylation cycle that is essential for efficient starch breakdown or with inhibition of starch hydrolysis by beta-amylase. Nonaqueous fractionation of leaves showed that Tre6P is predominantly located in the cytosol, with estimated in vivo Tre6P concentrations of 4 to 7 µM in the cytosol, 0.2 to 0.5 µM in the chloroplasts, and 0.05 µM in the vacuole. It is proposed that Tre6P is a component in a signaling pathway that mediates the feedback regulation of starch breakdown by sucrose, potentially linking starch turnover to demand for sucrose by growing sink organs at night....
Purification and characterization of a thermostable alpha-amylase produced by the fungus Paecilomyces variotii
(ELSEVIER SCI LTD, 2010)
An alpha-amylase produced by Paecilomyces variotii was purified by DEAE-cellulose ion exchange chromatography, followed by Sephadex G-100 gel filtration and electroelution. The alpha-amylase showed a molecular mass of 75 ...
Purification and biochemical characterization of a novel alpha-glucosidase from Aspergillus niveus
(SPRINGER, 2009)
An extracellular alpha-glucosidase produced by Aspergillus niveus was purified using DEAE-Fractogel ion-exchange chromatography and Sephacryl S-200 gel filtration. The purified protein migrated as a single band in 5% PAGE ...