Data/hora: 18/06/2024 04:30:54

Provedor de dados: | 52
País: | Brazil
Título: | Application of xylanases from Amazon Forest fungal species in bleaching of eucalyptus kraft pulps
Autores: | Medeiros,Roseli Garcia; Silva Jr.,Francides Gomes da; Báo,Sônia Nair; Hanada,Rogério; Ferreira Filho,Edivaldo Ximenes.
Data: | 2007-03-01
Ano: | 2007
Palavras-chave: | Xylan; Xylanase; Kraft pulp; Pulp bleaching.
Resumo: | Crude xylanase preparations from Penicillium corylophilum, Aspergillus niger and Trichoderma longibrachiatum were used to treat Eucalyptus kraft pulp, prior to chlorine dioxide and alkaline bleaching sequences. The enzyme pretreatment improved brightness and delignification of non-delignified and oxygen-bleached samples of eucalyptus kraft pulp. Xylanase preparations from T. longibrachiatum and P. corylophilum were more effective to reduce pulp kappa number. A small reduction in viscosity was obtained when the oxygen-bleached pulp was treated with xylanase preparation from A. niger. For all enzyme samples, the best release of chromophoric material from the pulp was at 237 nm. The enzyme preparation from P. corylophilum was responsible for the highest release of reducing sugar at a dosage interval of 10-20 IU/g dry weight pulp. Scanning electron microscopy studies of oxygen-bleached pulp after xylanase treatment revealed morphological changes, including holes, cracks, filament forming and peeling.
Tipo: | Info:eu-repo/semantics/article
Idioma: | Inglês
Identificador: | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132007000200008
Editor: | Instituto de Tecnologia do Paraná - Tecpar
Relação: | 10.1590/S1516-89132007000200008
Formato: | text/html
Fonte: | Brazilian Archives of Biology and Technology  v.50 n.2 2007
Fonte: | info:eu-repo/semantics/openAccess