The role of two Trichoderma reesei xylanases in the bleaching of pine kraft pulp

Büchert, Johanna; Ranua, Marjatta; Kantelinen, Anne; Viikari, Liisa

doi:10.1007/bf00174853

Cited by 52 publications

(21 citation statements)

References 6 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Trichoderma consists of a number of economically important strains, valued for their biocontrol capabilities and ability to produce beneficial metabolites and enzymes (Papavizas, 1985 ;Ghisalberti & Sivasithamparam, 1991 ;Buchert et al, 1992 ;Schirmbock et al, 1994). In contrast to their usefulness to industry, however, there have also been reports of pathogenic strains that pose a threat to both horticulture and human health (Loeppke et al, 1983 ;Seaby, 1987 ;Menzies, 1993).…”

mentioning

confidence: 99%

Examination of Trichoderma phylogenies derived from ribosomal DNA sequence data

Dodd

Crowhurst

Rodrigo

et al. 2000

Mycological Research

View full text Add to dashboard Cite

Ribosomal DNA sequences were assessed for their usefulness in distinguishing among Trichoderma isolates and for their robustness in resolving their phylogenetic relationships. DNA sequences from the D2 region of the 28S rRNA gene were determined for 50 Trichoderma isolates representing seven species. Eight distinct sequence types existed, and were mostly consistent with groupings based on morphology. Sequence variability within the D2 region alone was not sufficient to provide a reliable phylogeny. Sequences from the ITS1, 5.8S and ITS2 regions were subsequently determined for 18 of the isolates. Eight distinct ITS sequence types were detected among these 18 isolates. The ITS sequence types were generally consistent with morphology, ITS1 sequence data supported the identification of the Th3 T. harzianum group of Muthumeenakshi et al. (1994) as T. atroviride. The data also confirmed that the biocontrol strains of this study were different from those causing disease problems in the mushroom industry in Europe and North America. Results from the phylogenetic analysis stress the importance of testing the robustness of data used to predict phylogenies. Two ITS sequence data sets for the same group of isolates produced significantly different phylogenies. Congruence analysis detected that T. inhamatum (GJS90-90) was corrupting tree topologies and ' first order pruning ' was performed by removing its sequence from the two ITS data sets. Subsequent differences in the topologies of pruned ITS1 and ITS2 trees were attributed to a lack of phylogenetic information in the ITS2 sequence region. Although ITS sequences successfully differentiated among morphologically distinct isolates within Trichoderma, it did not provide a sufficient phylogenetic signal to resolve all of their relationships.

show abstract

mentioning

confidence: 99%

Examination of Trichoderma phylogenies derived from ribosomal DNA sequence data

Dodd

Crowhurst

Rodrigo

et al. 2000

Mycological Research

View full text Add to dashboard Cite

show abstract

“…The bleachability varied considerably depending on the origin of the enzyme and the type of the pulp. The mannanase purified from T. reesei was most effective in increasing the brightness of the pulps Based on data from Buchert, 1993;Buchert et al, 1992aBuchert et al, , 1992bClark et al, 1990;Clark et al, 1991. Original kappa number 34.4. Enzyme doses: xylanase 100 nKat g −1 , mannanase 500 nKat g −1 .…”

Section: A Impact Of Different Hemicellulase Enzymes In Bleachingmentioning

confidence: 97%

Biological Bleaching of Chemical Pulps

Bajpai¹

2004

Critical Reviews in Biotechnology

153

View full text Add to dashboard Cite

Use of biotechnology in pulp bleaching has attracted considerable attention and achieved interesting results in recent years. Enzymes of the hemicellulolytic type, particularly xylan-attacking enzymes, xylanases are now used commercially in the mills for pulp treatment and subsequent incorporation into bleach sequences. The aims of the enzymatic treatment depend on the actual mill conditions and may be related to environmental demands, reduction of chemical costs or maintenance or even improvement of product quality. The use of oxidative enzymes from white-rot fungi, that can directly attack lignin, is a second-generation approach, which could produce larger chemical savings than xylanase but has not yet been developed to the full scale. It is being studied in several laboratories in Canada, Japan, the U.S.A. and Europe. Certain white-rot fungi can delignify kraft pulps increasing their brightness and their responsiveness to brightening with chemicals. The fungal treatments are too slow but the enzyme manganese peroxidase and laccase can also delignify pulps and enzymatic processes are likely to be easier to optimize and apply than the fungal treatments. Development work on laccase and manganese peroxidase continues. This article presents an overview of developments in the application of hemicellulase enzymes, lignin-oxidizing enzymes and white-rot fungi in bleaching of chemical pulps. The basic enzymology involved and the present knowledge of the mechanisms of the action of enzymes as well as the practical results and advantages obtained on the laboratory and industrial scale are discussed.

show abstract

“…Pulpzyme HA (Novo Nordisk A/S) produced by T. reesei was the first commercially available xylanase to be used in the biobleaching of wood pulps and was capable of a 20% decrease in kappa number for oxygen-delignified birch kraftpulp (Ziaie-Shirkolaee et al 2008).The two major xylanases of T. reesei were ever compared for increasing the bleachability of pine kraft pulp, and the result suggested that the pI 9.0 xylanase act better on the pulp than the pI 5.5 xylanase (Buchert et al 1992). …”

Section: Introductionmentioning

confidence: 97%

Production of a Trichoderma reesei QM9414 xylanase in Pichia pastoris and its application in biobleaching of wheat straw pulp

Ouyang

Shen

Wang

et al. 2010

World J Microbiol Biotechnol

View full text Add to dashboard Cite

The purpose of this study was to produce a Trichoderma reesei xylanase (XYN2) in Pichia pastoris and to test its potential application for pulp bleaching. The recombinant xylanase was purified by a two-step process of ultrafiltration and gel filtration chromatography. The molecular mass of the recombinant enzyme was 21 and 25 kDa by SDS-PAGE analysis, due to different glycosylation of the native protein. The optimum pH and temperature of the recombinant XYN2 was 5.0 and 50°C. Enzyme activity was stable at 50°C and at pH 5.0-7.0. The bleaching ability of the recombinant xylanase was also studied at 50°C and pH 6.0, using wheat straw pulp. Biobleaching of the xylanase produced chlorine dioxide savings of up to 60%, while retaining brightness at the control level and led to a lower kappa number and small enhancements in tensile, burst and tear strength of pulp fibers.

show abstract

The role of two Trichoderma reesei xylanases in the bleaching of pine kraft pulp

Cited by 52 publications

References 6 publications

Examination of Trichoderma phylogenies derived from ribosomal DNA sequence data

Examination of Trichoderma phylogenies derived from ribosomal DNA sequence data

Biological Bleaching of Chemical Pulps

Production of a Trichoderma reesei QM9414 xylanase in Pichia pastoris and its application in biobleaching of wheat straw pulp

Contact Info

Product

Resources

About