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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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Oliveira,Patrícia Lopes de; Duarte,Marta Cristina Teixeira; Ponezi,Alexandre Nunes; Durrant,Lúcia Regina. |
The production of manganese peroxidase (MnP) from Bacillus pumilus and Paenibacillus sp. was studied under absence and presence of the inducers indulin AT, guayacol, veratryl alcohol, lignosulfonic acid and lignosulfonic acid desulfonated. Indulin AT increased the activity of B. pumilus MnP up to 31.66 U/L after 8 h, but no improve was observed for Paenibacillus sp., which reached maximum activity (12.22 U/L) after 20 h. Both MnPs produced by these microorganisms were purified in phenyl sepharose resin and the proteins from crude extracts were eluted in two fractions. However, only the first fraction of each extract exhibited MnP activities. Tests in different pH and temperature values, from pH 5.0 to pH 10.0 and 30 ºC to 60 ºC, respectively, were carried... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Bacillus pumilus; Paenibacillus sp.; Manganese peroxidase; Purification; Characterization. |
Ano: 2009 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822009000400012 |
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