The white rot fungus Bjerkandera sp. strain BOS55 extensively delignified and bleached oxygen-delignified eucalyptus kraft pulp handsheets. Biologically mediated brightness gains of up to 14 ISO (International Standards Organization units) were obtained, providing high final brightness values of up to 80% ISO. In nitrogen-limited cultures (2.2 mM N), manganese (Mn) greatly improved manganese-de...

Some pretreatments that swell and/or open the structure of wood fibers could increase the effectiveness of a biobleaching process, allowing for an industrial application. To this end, a chemical pretreatment (urea, U), a physical pretreatment (refining, R), and their combinations (RU and UR) were optimized to evaluate and compare their enhancement of the LE biobleaching sequence (laccase-mediat...

Xylanases are hydrolytic enzymes which cleave the β-1, 4 backbone of the complex plant cell wall polysaccharide xylan. Xylan is the major hemicellulosic constituent found in soft and hard food. It is the next most abundant renewable polysaccharide after cellulose. Xylanases and associated debranching enzymes produced by a variety of microorganisms including bacteria, actinomycetes, yeast and fu...

The potential of extracellular alkali stable and thermo tolerant xylanase produced by Bacilluspumilus SV-85S through solid state fermentation was investigated in pulp bleaching in association with conventional bleaching using chlorine and chlorine dioxide. The biobleaching of kraft pulp with xylanase was the most effective at an enzyme dose of 10 IU/g oven dried pulp, pH 9.0 and 120 min incubat...

Wheat straw pulp can be considered to be one of most important raw materials for specialty and functional paper products. Bleaching sequences involving laccase and xylanase were applied to bleach wheat straw pulp. The bleached pulp properties after a sequence of xylanase (X), laccase (L), and extraction (E), i.e. XLE, were compared with those of LE and LEX sequences. It was found that the XLE b...

In this work, a xylanase-producing strain, Streptomyces griseorubens LH-3, was cultured, and the crude xylanase was prepared. Analysis of its enzymatic properties revealed that the crude xylanase possessed good thermal stability at temperatures below 60 o C, exhibited a wide pH range from 4.0 to 9.0, and was cellulase-free. This crude enzyme was used to treat eucalyptus kraft pulp, and the rele...

A potential lignolytic fungus, Stereum ostrea was analysed for the decolourisation of industrial effluents discharged from rayon pulp mills. The colour removal was from 5580.85 to 2690.05 CU during 40 days of incubation time. The laccase activity during the decolorization process was increased up to 20 day (862.77 U/L) and after that it was very low. Chemical bleaching was effective and showed ...

Xylanase is a major enzyme used in the paper and pulp industries for biobleaching applications. There are possibilities for xylanase with better properties suitable for industrial applications. This paper focused on a potential xylanolytic fungus, Trichoderma viride VKF-3, obtained from a mangrove soil sample. Optimum conditions for xylanase production were tested by culturing T. viride VKF3 un...