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| Borsari, Raquel Renan Jorge; Universidade Estadual de Londrina; Buzato, João Batista; UEL; Silva, Rui Sérgio dos Santos Ferreira da; UEL; Celligoi, Maria Antonia Pedrini Colabone; UEL. |
| The effect of the variables pantothenic acid, yeast extract and sodium chloride, as well as the cell permeabilization technique, were investigated on the formation of levan, ethanol, sorbitol and biomass of Zymomonas mobilis, using a 24-1 fraction factorial design. Cell growth was determined by turbidimetry at 605 nm, relating it to a biomass with a dry weight calibration curve. Reducing sugars were quantified according to Somogyi and Nelson. Total sugars were quantified by the phenol-sulfuric acid method, sorbitol by HPLC and ethanol. The levan produced was precipitated by the addition of absolute ethanol and quantified in fructose units. In levan biosynthesis, the variable that had the largest contribution was cell condition. The results suggested that... |
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Palavras-chave: 2.08.02.00-5; 2.12.02.02-8 Zymomonas mobilis; Fermentation; Biomass; Substrate; Sorbitol; Levan Bioquímica dos microrganismos; Microbiologia industrial e de fermentação Zymomonas mobilis; Fermentation; Biomass; Substrate; Sorbitol; Levan. |
| Ano: 2010 |
URL: http://periodicos.uem.br/ojs/index.php/ActaSciBiolSci/article/view/1519 |
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| Melo,Fernando Cesar Bazani Cabral de; Zaia,Cássia Thaïs Bussamra Viera; Celligoi,Maria Antonia Pedrine Colabone. |
| Levan is an exopolysaccharide of fructose primarily linked by β-(2→6) glycosidic bonds with some β-(2→1) branched chains. Due to its chemical properties, levan has possible applications in both the food and pharmaceutical industries. Bacillus subtilis is a promising industrial levan producer, as it ferments sucrose and has a high levan-formation capacity. A new strain of B. subtilis was recently isolated from Japanese food natto, and it has produced levan in large quantities. For future pharmaceutical applications, this study aimed to investigate the effects of levan produced by B. subtilis Natto, mainly as potential hypoglycemic agent, (previously optimized with a molecular weight equal to 72.37 and 4,146 kDa) in Wistar male rats with diabetes induced by... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Levan; Bacillus subtilis Natto; Hypoglycemia. |
| Ano: 2012 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822012000400046 |
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| Melo,I.R.; Pimentel,M.F.; Lopes,C.E.; Calazans,G.M.T.. |
| Levan is a non-toxic, biologically active, extra cellular polysaccharide composed solely by fructose units. Optimization of levan production by Zymomonas mobilis strain ZAG-12 employing a 2(4-1) fractional factorial design was performed to analyze the influence of the temperature (20, 25 e 30ºC) agitation (50, 75 e 100 rpm), and the initial concentrations of both sucrose (150, 200 e 250 g.L-1) and yeast extract (2.0, 3.5 e 5.0g.L-1) on final levan concentration. Aerobic fermentation was performed batchwise in 500mL Pyrex flasks for 72 hours. Biomass, ethanol, levan and sucrose were determined at beginning and also at end of the fermentations. The experiments showed that the final levan concentration depended on initial sucrose concentration, temperature... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Factorial design; Levan; Zymomonas mobilis. |
| Ano: 2007 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822007000100010 |
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