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| Slivinski,Christiane Trevisan; Machado,Alex Vinicius Lopes; Iulek,Jorge; Ayub,Ricardo Antônio; Almeida,Mareci Mendes de. |
| In this work, glucoamylase was produced by Aspergillus niger in solid-state fermentation. The enzyme was partially purified by ammonium sulphate precipitation and ion exchange and gel filtration chromatographies. Its molecular mass was estimated as 118.17 kDa by electrophoresis. The partially purified enzyme had an optimum pH range of 4.5-5.0 and an optimum temperature of 60 °C, with average activity 152.85 U mL-1. Thermal and pH stability assays with the crude extract showed that more than 60 % of the activity remained at pH 4.6 and 60 °C, even after an exposition to these conditions longer than 24 h. Yet, after purification, the enzyme was stable at these for at least 4 h, which indicated that its purification for use in starch saccharification was... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Glucoamylase; Aspergillus niger; Solid-state fermentation; Biochemical characterization; Purification. |
| Ano: 2011 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132011000300018 |
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| Almeida,Paula Zaghetto de; Pereira,Marita Gimenez; Carvalho,Caio Cesar de; Heinen,Paulo Ricardo; Ziotti,Luciana Sobrani; Messias,Josana Maria; Jorge,João Atilio; Polizeli,Maria de Lourdes Teixeira de Moraes. |
| Abstract Filamentous fungi are widely diverse and ubiquitous organisms. Such biodiversity is barely known, making room for a great potential still to be discovered, especially in tropical environments - which are favorable to growth and species variety. Filamentous fungi are extensively applied to the production of industrial enzymes, such as the amylases. This class of enzymes acts in the hydrolysis of starch to glucose or maltooligosaccharides. In this work twenty-five filamentous fungi were isolated from samples of decomposing material collected in the Brazilian Atlantic Forest. The two best amylase producers were identified as Aspergillus brasiliensis and Rhizopus oryzae. Both are mesophilic, they grow well in organic nitrogen-rich media produce great... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Amylase; Filamentous fungi; Aspergillus brasiliensis; Rhizopus oryzae; Glucoamylase; Bioprospection. |
| Ano: 2017 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1676-06032017000300204 |
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| Ferreira-Nozawa,M.S.; Rezende,J.L.; Guimarães,L.H.S.; Terenzi,H.F.; Jorge,J.A.; Polizeli,M.L.T.M.. |
| 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 by 15.1 strain was sequentially submitted to DEAE-Cellulose and CM-Cellulose chromatography, and purified 141-fold, with 5.45% recovery. The glucoamylase of strain 15.8 was purified 71-fold by CM-Cellulose and Concanavalin A-Sepharose chromatography, with 7.38% recovery. Temperature and pH optima were in the range of 50-60ºC and 5.0-6.0, respectively, using starch and maltose as substrates. The glucoamylase of S. thermophilum 15.8 was more stable (t50 > 60 min) than that of S. thermophilum 15.1 (t50= 11-15 min), at 60ºC. The glucoamylase... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Glucoamylase; Amylase; Scytalidium thermophilum; Thermostable enzyme; Starch hydrolysis. |
| Ano: 2008 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822008000200027 |
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| Pavezzi,Fabiana Carina; Gomes,Eleni; Silva,Roberto da. |
| Glucoamylase is widely used in the food industry to produce high glucose syrup, and also in fermentation processes for production beer and ethanol. In this work the productivity of the glucoamylase of Aspergillus awamori expressed by the yeast Saccharomyces cerevisiae, produced in submerged fermentation using different starches, was evaluated and characterized physico-chemically. The enzyme presented high specific activity, 13.8 U/mgprotein or 2.9 U/mgbiomass, after 48 h of fermentation using soluble starch as substrate. Glucoamylase presented optimum activity at temperature of 55ºC, and, in the substratum absence, the thermostability was for 1h at 50ºC. The optimum pH of activity was pH 3.5 - 4.0 and the pH stability between 5.0 and 7.0. The half life at... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Glucoamylase; Aspergillus awamori; Saccharomyces cerevisiae; Corn starch; Potato starch; Cassava starch. |
| Ano: 2008 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822008000100024 |
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| Silva,Roberto do Nascimento; Quintino,Fábio Pereira; Monteiro,Valdirene Neves; Asquieri,Eduardo Ramirez. |
| The high demands for sugars and the development of enzymatic technology have increased the production of sweeteners, especially for glucose and fructose syrups. This work describe a technology for glucose and fructose syrups from Brazilian cassava starch using enzymes produced by soil microrganisms isolated from the Brazilian Cerrado soil. Firstly, Aspergillus niger and Streptomyces sp. were isolated from the soil and used as glucoamylase (GA) and glucose isomerase (GI) producer sources. After characterization, GA and GI exhibited optimum pH 4.5 and 8.0, respectively. GA showed maximum activity at 60 ºC and GI at 85 ºC. GA and GI retained 65 and 80%, respectively, of initial activity after 180 minutes of incubation at 60 ºC. The kinetic parameters Km and... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Glucoamylase; Glucose isomerase; Glucose-fructose syrups; Cassava. |
| Ano: 2010 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0101-20612010000100031 |
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| Cao,Qinghua; Li,Tao; Shao,Huanhuan; Tan,Xuemei; Zhang,Yizheng. |
| Background: Zymomonas mobilis, as a novel platform for bio-ethanol production, has been attracted more attention and it is very important to construct vectors for the efficient expression of foreign genes in this bacterium. Results: Three shuttle vectors ( pSUZM 1, pSUZM2 and pSUZM3 ) were first constructed with the origins of replication from the chromosome and two native plasmids (pZZM401 and pZZM402) of Z. mobilis ZM4, respectively. The three shuttle vectors were stable in Z. mobilis ZM4 and have 3,32 and 27 copies, respectively. The promoter Ppdc (a), from the pyruvate decarboxylase gene, was clonedinto the shuttle vectors, generatingthe expressionvectors pSUZM1(2, 3)a. The codon-optimized glucoamylase gene from Aspergillus awamori combined with the... |
| Tipo: Journal article |
Palavras-chave: Expression vector; Gene expression; Glucoamylase; Zymomonas mobilis. |
| Ano: 2016 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582016000100006 |
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| Dulermo, Remi; Brunel, Francois; Dulermo, Thierry; Ledesma-amaro, Rodrigo; Vion, Jeremy; Trassaert, Marion; Thomas, Stephane; Nicaud, Jean-marc; Leplat, Christophe. |
| Background The yeast Yarrowia lipolytica is an increasingly common biofactory. To enhance protein expression, several promoters have been developed, including the constitutive TEF promoter, the inducible POX2 promotor, and the hybrid hp4d promoter. Recently, new hp4d-inspired promoters have been created that couple various numbers of UAS1 tandem elements with the minimal LEU2 promoter or the TEF promoter. Three different protein-secretion signaling sequences can be used: preLip2, preXpr2, and preSuc2. Results To our knowledge, our study is the first to use a set of vectors with promoters of variable strength to produce proteins of industrial interest. We used the more conventional TEF and hp4d promoters along with five new hybrid promoters: 2UAS1-pTEF,... |
| Tipo: Text |
Palavras-chave: Yarrowia lipolytica; Protein production; RedStar2; Glucoamylase; Xylanase; Hybrid promoters. |
| Ano: 2017 |
URL: https://archimer.ifremer.fr/doc/00428/54003/55193.pdf |
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