Application of xylanases from Amazon Forest fungal species in bleaching of eucalyptus kraft pulps

Abstract

ABSTRACT

Xylanase and β-Xylosidase from Penicillium janczewskii: Production, Physico-chemical Properties, and Application of the Crude Extract to Pulp Biobleaching

“…A comparison among the results of this study and those using other xylanases is difficult, due to differences in the origin and characteristics of the pulp, differences in pulp pretreatment, different processing conditions, and also due to enzyme characteristics. The reduction obtained in the treatments with P. janczewskii xylanases was higher than to those obtained with some other fungal xylanases, which normally present reductions between 0.9 and 4.6 units in kappa number Madlala et al 2001;Maximo et al 1998;Medeiros et al 2007;Michelin et al 2010;Nair et al 2010;Peixoto-Nogueira et al 2009;Taneja et al 2002). Only one study reported greater reduction, i.e., 10.0, treating a cellulose pulp with A. niger xylanases (Raghukumar et al 2004).…”

Optimization of Xylanase Production fromAspergillus nigerfor Biobleaching of Eucalyptus Pulp

“…6) Xylanases from many microbial sources have been studied for their application in the bleaching of various pulps, including eucalyptus, wheat straw, and bagasse. [7][8][9][10] The enzymes are either crude enzyme preparations from wild-type bacterial and fungal strains e.g., Bacillus pumilus, 9) Aspergillus sp., [11][12][13] Trichoderma sp., and Penicillum sp. 8) or purified wild-type or recombinant enzymes e.g., xylanase from A. fischeri, 14) A. caespitosus, 15) and A. fumigatus.…”

Enzymatic bleaching of kraft pulp by xylanase from Aspergillus sydowii SBS 45

“…The increase in brightness up to 3.93% in wheat straw pulp was reported when it was treated by xylanase from Thermomyces lanuginosus 288.54 by Li et al [17]. Medeiros et al [18] reported reduction in kappa number and improvement of brightness in kraft pulps after bleaching with xylanases from A.niger, T.longibrachiatum and P.corylophilum. After treating with xylanase, an increase in brightness and reduction in kappa number in bagasse pulp and kraft pulp was reported by Madlala et al [24].…”

“…The reducing sugar release was maximum at 25 U g -1 . Medeiros et al [18] reported that the release of chromophores is a better indication of xylanase action on pulp than reducing sugar because the reducing sugars can be produced continuously from the xylo-oligomers produced by the initial hydrolysis of xylan from pulp. This might be the reason for the elevated level of reducing sugars in fi ltrates.…”