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| Oliveira Junior,Enio Nazaré de; Melo,Itamar Soares de; Franco,Telma Teixeira. |
| In this work, changes in the hyphal morphology due to chitosan treatment in some fungal species were studied. Scanning electron microscope (SEM) observations revealed that chitosans with molar fraction of acetyl groups (F A 0.16 and 0.18) and degree of polymerization (DP 1,089 and 1,242) had a direct effect on the morphology of the chitosan-treated fungi, reflecting its potential for causing a delay in the growth of Alternaria alternata (500 µg × mL-1), Botrytis cinerea (1,000 µg × mL-1), Penicillium expansum (1,000 µg × mL-1) and Rhizopus stolonifer (500 µg × mL-1). Mycelial aggregation and structural changes such as excessive branching, swelling of the cell wall and hyphae size reduction were observed in the micrographs. |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Chitosan; Alternative control of fungi; Antifungal activity; Plant pathogenic fungi; Fungal morphology. |
| Ano: 2012 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132012000500001 |
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| Duarte,Marta Cristina Teixeira; Pellegrino,Ana Carolina Alcazar; Portugal,Edilberto Princi; Ponezi,Alexandre Nunes; Franco,Telma Teixeira. |
| Alkaline xylanases produced by four different strains of Bacillus pumilus were characterized. The optimal pH and temperature were pH 9.0 and 60ºC for strain 13a, and pH 8.0 and 55ºC for strains 5(2), 5(14), and 4a. Under these conditions the following activities were found after 10 min in the presence of 1% xylan (birchwood): 328 U.ml-1, 131 U.ml-1, 90 U.ml-1, and 167 U.ml-1, respectively, for the four strains. The enzymes were stable at 40ºC, with 40% of the xylanase activity remaining after 2 hours for the enzymes of strain 5(2) and 60% for the other three strains. Stability at 50ºC was improved by addition of glycerol. Taking into account the conditions under which kraft pulps are bleached during the manufacture of paper, xylanases from B. pumilus... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Xylan xylanase; B pumilus kraft pulp bleaching. |
| Ano: 2000 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822000000200005 |
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| Tagliari,Cristiane Vanessa; Sanson,Raquel K.; Zanette,André; Franco,Telma Teixeira; Soccol,Carlos Ricardo. |
| Various microorganisms including bacteria, yeast and fungi can degrade caffeine. There are few publications about caffeine degradation pathway in filamentous fungi, mainly by solid-state fermentation (SSF). Studies were carried out on degradation of caffeine and their metabolites by filamentous fungi in SSF using coffee husk as substrate. The purpose of this work was to investigate the caffeine degradation pathway by Rhizopus delemar in packed bed column fermenter and to compare this degradation metabolism with glass flasks fermentation. The methylxanthines were quantified by HPLC analysis. The experiments were realized with the optimized conditions in previous experiments: pH 6.5, 28ºC, inoculation rate 10(6) spores/g substrate, aeration rate 60 mL/min... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Decaffeination; Fermentation; Caffeine; Theophylline; Bioreactor; Filamentous fungi. |
| Ano: 2003 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822003000500035 |
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