Consulta: creatorFacets:"Silva,Roberto da"
Registros recuperados: 12
Data/hora: 11/06/2024 11:58:16

Ribonuclease Production by Aspergillus species
Provedor de dados: 59
Autores: Gomes,Eleni; Silva,Roberto da; Serzedello,Alcides.
Ribonuclease production by Aspergillus flavipes, A. sulphureus and A. fischeri in semi-synthetic medium, after 24-144 hours at 30ºC under shaking, was studied. After cultivation, the medium was separated from micelia by filtration and the resultant solution was used as enzymatic extract. The highest amount of biomass and RNase was obtained after 96 hours of cultivation. The enzymes produced by three species presented similar characteristics, with optimum temperature at 55ºC and two peaks of activity at pH 4.5 and 7.0. A. flavipes RNases were more sensitive to temperature: 50% of the initial activity was lost after 1 hour at 70ºC. After this heat treatment, RNase of A. sulphureus lost 30% of this activity and that of A. fischeri only 16%. The nucleotides...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Ribonucleases; Aspergillus; Nucleotides.
Ano: 1998
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37141998000300008

Screening of bacterial strains for pectinolytic activity: characterization of the polygalacturonase produced by Bacillus sp
Provedor de dados: 59
Autores: Soares,Márcia M.C.N.; Silva,Roberto da; Gomes,Eleni.
One hundred sixty eight bacterial strains, isolated from soil and samples of vegetable in decomposition, were screened for the use of citrus pectin as the sole carbon source. 102 were positive for pectinase depolymerization in assay plates as evidenced by clear hydrolization halos. Among them, 30% presented considerable pectinolytic activity. The cultivation of these strains by submerged and semi-solid fermentation for polygalacturonase production indicated that five strains of Bacillus sp produced high quantities of the enzyme. The physico-chemical characteristics, such as optimum pH of 6.0 - 7.0, optimum temperatures between 45oC and 55oC, stability at temperatures above 40oC and in neutral and alkaline pH, were determined.
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Bacillus sp; Polygalacturonase; Pectinolytic activity.
Ano: 1999
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37141999000400002

Localization and partial characterization of thermostable glucoamylase produced by newly isolated Thermomyces lanuginosus TO3 in submerged fermentation
Provedor de dados: 52
Autores: Gonçalves,Aline Zorzetto Lopes; Carvalho,Ana Flávia Azevedo; Silva,Roberto da; Gomes,Eleni.
Thermophilic Thermomyces lanuginosus strain TO3 was isolated from compost pile samples and was used for its ability to produce considerable glucoamylase activity when growing in liquid medium at 45ºC with starch as the sole carbon source. Enzyme productivity was high in submerged fermentation (SmF) with maximum activity of 13 U/mL after 168 h of fermentation. Higher quantities of glucose were released when the substrate for enzyme was soluble starch than maltose or maltooligosaccharides were used. The distribution of glucoamylase between the extracellular and cell-associated fractions varied according to fermentation time. Glucoamylase produced from T. lanuginosus TO3 had optimum activity at 65 ºC and good thermostability in the absence of substrate, with...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Glucoamylase; Submerged fermentation; Thermomyces lanuginosus.
Ano: 2008
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132008000400024

Pectinase production by fungal strains in solid-state fermentation using agro-industrial bioproduct
Provedor de dados: 52
Autores: Martin,Natalia; Souza,Simone Regina de; Silva,Roberto da; Gomes,Eleni.
Pectin lyase and polygalacturonase production by newly isolated fungal strains was carried out in solid-state fermentation. Moniliella SB9 and Penicillium sp EGC5 produced polygalcturonase (PG) and pectin lyase (PL) on mixture of orange bagasse, sugar cane bagasse and wheat bran as substrate. PG and PL produced by Moniliella presented optimum activity at pH 4.5 and 10.0 and at 55 and 45°C, respectively, while these enzymes from Penicillium sp presented optimum activity at pH 4.5-5.0 and 9.0 and 40°C, respectively.
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Penicillium; Moniliella; Polygalacturonase; Pectin lyase.
Ano: 2004
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132004000500018

Selection of Xilose-Fermenting Yeast Strains
Provedor de dados: 52
Autores: Silva,Rosimeire Oenning da; Cereda,Marney Pascoli; Gomes,Eleni; Martins,Gisele Marta; Pagnocca,Fernando Carlos; Silva,Roberto da.
ABSTRACT In Brazil, ethanol is obtained by fermentat of sugar cane juice using Saccharomyces cerevisiae. The cane juice extraction generates the bagasse that has been used for obtaining generation biofuel. However, the sugarcane bagasse has 30% pentose that cannot be fermented to ethanol by S. cerevisiae. Thus the aim of this study was to isolate a yeast able to ferment xylose to ethanol. Samples of cane juice and flowers were used for the isolation of 165 strains that were then screened for ethanol production using plate testing. Among them, the ethanol positive strains Wickerhamomyces anomalus, Schizosaccharomyces pombe and Starmerella meliponinorum were selected for a xylose fermentation assay, using a semi-synthetic and bagasse hydrolysate as must. S....
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Xylose; Ethanol; Yeast; Sugarcane bagasse.
Ano: 2016
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132016000100419

Pectinase production by Penicillium viridicatum RFC3 by solid state fermentation using agricultural wastes and agro-industrial by-products
Provedor de dados: 58
Autores: Silva,Dênis; Martins,Eduardo da Silva; Silva,Roberto da; Gomes,Eleni.
Pectin lyase and polygalacturonase production by newly isolated Penicillium viridicatum strain Rfc3 was carried out by means of solid state fermentation using orange bagasse, corn tegument, wheat bran and mango and banana peels as carbon sources. The maximal activity value of polygalacturonase (Pg) (30U.g-1) was obtained using wheat bran as carbon source while maximal pectin lyase (Pl) (2000 U.g-1) activity value was obtained in medium composed of orange bagasse. Mixtures of banana or mango peels with sugar cane bagasse resulted in increased Pg and Pl production compared to fermentations in which this residue was not used. The mixture of orange bagasse and wheat bran (50%) increased the production of Pg and Pl to 55 U.g-1 and 3540 U.g -1 respectively....
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Penicillium viridicatum polygalacturonase pectin lyase wastes; By-product.
Ano: 2002
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822002000400008

Production and partial characterization of polygalacturonases produced by thermophilic Monascus sp N8 and by thermotolerant Aspergillus sp N12 on solid-state fermentation
Provedor de dados: 58
Autores: Freitas,Paula Mendes de; Martin,Natalia; Silva,Dênis; Silva,Roberto da; Gomes,Eleni.
Polygalacturonases production by newly isolated Monascus sp N8 and Aspergillus sp N12 strains was carried out in solid-state fermentation using mixtures of wheat bran, sugar cane bagasse and orange bagasse as carbon sources. The maximal activity values of exo-polygalacturonases (exo-Pg) from Monascus sp and Aspergillus sp were obtained using wheat bran/sugar cane bagasse/orange bagasse mixture (6.6 U/mL) and wheat bran/orange bagasse mixture (10 U/mL), respectively. Enzyme production by both strains was higher at 45ºC after 72 h and 1.6 U/mL at 50ºC after 120 h. Endo-polygalacturonase (endo-Pg) production was higher in wheat bran/orange bagasse mixture and was not affected by temperature of incubation for both fungi. Endo-Pg production by Monascus was 1.8...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Monascus sp; Aspergillus sp; Thermophilic; Polygalacturonase; Solid-state fermentation.
Ano: 2006
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822006000300019

Production of xylanase and CMCase on solid state fermentation in different residues by Thermoascus aurantiacus miehe
Provedor de dados: 58
Autores: Silva,Roberto da; Lago,Ellen S.; Merheb,Carolina W.; Macchione,Mariana M.; Park,Yong Kun; Gomes,Eleni.
The use of waste as raw material is important for government economy and natural balance. The purpose of this work was to study the production of CMCase and xylanase by a Brazilian strain of Thermoascus aurantiacus in solid state fermentation (SSF) using different agricultural residues (wheat bran, sugarcane bagasse, orange bagasse, corncob, green grass, dried grass, sawdust and corn straw) as substrates without enrichment of the medium and characterize the crude enzymes.The study of the extracellular cellulolytic and hemicellulolytic enzymes showed that T. arantiacus is more xylanolytic than cellulolytic. The highest levels of enzymes were produced in corncob, grasses and corn straw. All the enzymes were stable at room temperature by 24 h over a broad pH...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Thermoascus aurantiacus; Xylanase; CMCase; Solid state fermentation; Agricultural residues.
Ano: 2005
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822005000300006

Production of thermostable glucoamylase by newly isolated Aspergillus flavus A 1.1 and Thermomyces lanuginosus A 13.37
Provedor de dados: 58
Autores: Gomes,Eleni; Souza,Simone Regina de; Grandi,Roseli Picolo; Silva,Roberto da.
Thirteen thermophilic fungal strains were isolated from agricultural soil, tubers and compost samples in tropical Brazil. Two strains were selected based on of their ability to produce considerable glucoamylase activity while growing in liquid medium at 45ºC with starch as the only carbon source. They were identified as Aspergillus flavus A1.1 and Thermomyces lanuginosus A 13.37 Tsiklinsky. The experiment to evaluate the effect of carbon source, temperature and initial pH of the medium on enzyme production was developed in a full factorial design (2x2x3). Enzyme productivity was influenced by the type of starch used as carbon source. Cassava starch showed to be a better substrate than corn starch for glucoamylase production by A. flavus but for T....
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Glucoamylase; Alpha-glucosidase; Aspergillus; Thermomyces.
Ano: 2005
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822005000100015

Production and characterization of glucoamylase from fungus Aspergillus awamori expressed in yeast Saccharomyces cerevisiae using different carbon sources
Provedor de dados: 58
Autores: 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

The isolation of pentose-assimilating yeasts and their xylose fermentation potential
Provedor de dados: 58
Autores: Martins,Gisele Marta; Bocchini-Martins,Daniela Alonso; Bezzerra-Bussoli,Carolina; Pagnocca,Fernando Carlos; Boscolo,Maurício; Monteiro,Diego Alves; Silva,Roberto da; Gomes,Eleni.
ABSTRACT For the implementation of cellulosic ethanol technology, the maximum use of lignocellulosic materials is important to increase efficiency and to reduce costs. In this context, appropriate use of the pentose released by hemicellulose hydrolysis could improve de economic viability of this process. Since the Saccharomyces cerevisiae is unable to ferment the pentose, the search for pentose-fermenting microorganisms could be an alternative. In this work, the isolation of yeast strains from decaying vegetal materials, flowers, fruits and insects and their application for assimilation and alcoholic fermentation of xylose were carried out. From a total of 30 isolated strains, 12 were able to assimilate 30 g L-1 of xylose in 120 h. The strain Candida...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Xylose; Yeasts; Ethanol.
Ano: 2018
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822018000100162

Ligninases production by Basidiomycetes strains on lignocellulosic agricultural residues and their application in the decolorization of synthetic dyes
Provedor de dados: 58
Autores: Gomes,Eleni; Aguiar,Ana Paula; Carvalho,Caio César; Bonfá,Maricy Raquel B.; Silva,Roberto da; Boscolo,Mauricio.
Wood rotting Basidiomycetes collected in the "Estação Ecológica do Noroeste Paulista", São José do Rio Preto, São Paulo State, Brazil, concerning Aphyllophorales order and identified as Coriolopsis byrsina SXS16, Lentinus strigellus SXS355, Lentinus sp SXS48, Picnoporus sanguineus SXS 43 and Phellinus rimosus SXS47 were tested for ligninases production by solid state fermentation (SSF) using wheat bran or rice straw as culture media. C. byrsina produced the highest laccase (200 U mL-1) and Lentinus sp produced the highest activities of manganese peroxidase (MnP) and lignin peroxidase (LiP) (7 and 8 U mL-1, respectively), when cultivated on wheat bran. The effect of N addition on enzyme production was studied in medium containing rice straw and the data...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Laccase; Manganese peroxidase; Lignin peroxidase; Basidiomycetes; Decolorization; Synthetic dye.
Ano: 2009
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822009000100005