scispace - formally typeset
Search or ask a question
Journal ArticleDOI

Biomechanical Pulping of Loblolly Pine Chips with Selected White-Rot Fungi

01 Jan 1993-Holzforschung (Walter de Gruyter, Berlin / New York)-Vol. 47, Iss: 1, pp 36-40
TL;DR: Based on energy savings and improvements in the strength properties, regardless of bioreactor type, the white-rot fungus Ceriporiopsis subvermispora appeared to be superior to the otherwhite-rot fungi tested.
Abstract: Paper optical properties handsheets, whereas brightness and light scattering coefficient of the handsheets were decreased after all of the fungal treatments. Opacity of the handsheets after the fungal treatments remained unchanged. Loblolly pine (Pinus taeda) White-rot fungi Based on energy savings and improvements in the strength properties, regardless of bioreactor type, the white-rot fungus Ceriporiopsis subvermispora appeared to be superior to the other white-rot fungi tested. When incubated in stationary tray bioreactors, C. subvermispora caused only 6% weight loss, saved 42% energy during fiberization and refining, improved burst index by 32% and tear index by 67%, as compared to the control.
Citations
More filters
Journal ArticleDOI
TL;DR: The most efficient lignin degraders, estimated by 14CO2 evolution from 14C-[Ring]-labelled synthetic lign in (DHP), belong to the first group, whereas many of the most selective lignIn-degrading fungi belong toThe second, although only moderate to good [14C]DHP mineralization is obtained using fungi from this group.
Abstract: White-rot fungi produce extracellular lignin-modifying enzymes, the best characterized of which are laccase (EC 1.10.3.2), lignin peroxidases (EC 1.11.1.7) and manganese peroxidases (EC 1.11.1.7). Lignin biodegradation studies have been carried out mostly using the white-rot fungus Phanerochaete chrysosporium which produces multiple isoenzymes of lignin peroxidase and manganese peroxidase but does not produce laccase. Many other white-rot fungi produce laccase in addition to lignin and manganese peroxidases and in varying combinations. Based on the enzyme production patterns of an array of white-rot fungi, three categories of fungi are suggested: (i) lignin-manganese peroxidase group (e.g.P. chrysosporium and Phlebia radiata), (ii) manganese peroxidase-laccase group (e.g. Dichomitus squalens and Rigidoporus lignosus), and (iii) lignin peroxidase-laccase group (e.g. Phlebia ochraceofulva and Junghuhnia separabilima). The most efficient lignin degraders, estimated by 14CO2 evolution from 14C-[Ring]-labelled synthetic lignin (DHP), belong to the first group, whereas many of the most selective lignin-degrading fungi belong to the second, although only moderate to good [14C]DHP mineralization is obtained using fungi from this group. The lignin peroxidase-laccase fungi only poorly degrade [14C]DHP.

1,112 citations

Book ChapterDOI
TL;DR: This chapter describes the structure of wood and the main wood components, cellulose, hemicelluloses and lignins and the enzyme and enzyme mechanisms used by fungi and bacteria to modify and degrade these components are described in detail.
Abstract: One of natures most important biological processes is the degradation of lignocellulosic materials to carbon dioxide, water and humic substances. This implies possibilities to use biotechnology in the pulp and paper industry and consequently, the use of microorganisms and their enzymes to replace or supplement chemical methods is gaining interest. This chapter describes the structure of wood and the main wood components, cellulose, hemicelluloses and lignins. The enzyme and enzyme mechanisms used by fungi and bacteria to modify and degrade these components are described in detail. Techniques for how to assay for these enzyme activities are also described. The possibilities for biotechnology in the pulp and paper industry and other fiber utilizing industries based on these enzymes are discussed.

452 citations

Journal ArticleDOI
01 Feb 1995-Botany
TL;DR: The ratio of syringyl:guaiacyl lignin of different woods, different cell types, and even the different layers within a cell wall influenced the type and extent of decay by white-rot fungi.
Abstract: Degradation of the lignocellulose complex in wood varies depending on the microorganism causing decay. The degradative processes of white-, brown-, and soft-rot fungi as well as different forms of ...

289 citations

Journal ArticleDOI
TL;DR: Ethanol was produced by simultaneous saccharification and fermentation (SSF) from beech wood chips after bioorganosolve pretreatments by ethanolysis and white rot fungi, Ceriporiopsis subvermispora, which gave the highest yield on SSF.

233 citations

Journal ArticleDOI
TL;DR: Information obtained by immunoelectron microscopy and differential staining led to the conclusion that the biopulping effect obtained after 2 weeks of incubation cannot be explained by the direct action of enzymes on lignin or polysaccharides, and a low molecular mass agent is considered to be responsible for the biopsies.
Abstract: Treatment of wood chips with lignin-degrading fungi prior to pulping has been shown to have great potential for mechanical as well as chemical pulping on a laboratory scale. Ceriporiopsis subvermispora, when grown on aspen or loblolly pine for 4 weeks, was found to be superior to other fungi. On aspen there was an energy savings of 47%, and an increase in burst and tear indices of 22% and 119%, respectively. With loblolly pine, energy savings amounted to 37%, while burst and tear indices increased by 41% and 54%, respectively. The weight loss was only 6%, but a decrease in optical properties had to be accepted. After sulfite cooking of wood chips pretreated for 2 weeks, the Kappa number decreased by 30% with hard- and softwood. Tensile and tear indices decreased by only 10%, while the brightness of unbleached pulp increased by 4% with birch. Information obtained by immunoelectron microscopy and differential staining led to the conclusion that the biopulping effect obtained after 2 weeks of incubation cannot be explained by the direct action of enzymes on lignin or polysaccharides. Instead, a low molecular mass agent is considered to be responsible for the biopulping effect. These results have changed the aims of biopulping from an emphasis on removing the bulk of lignin to an emphasis on a short-term process, lasting 2 weeks and yielding a low mass loss. Data on these kinetics of fungal development and the degree of asepsis will help to scale-up the process. An advanced chip pile is assumed to be the most feasible process design, rather than a controlled enclosed reactor.

209 citations

References
More filters
Journal Article
TL;DR: Des copeaux de P.taeda ont ete traites par cinq souches de Ceriporiopsis subvermispora pendant quatre semaines avant mise en pâte mecanique sur raffineur as discussed by the authors.
Abstract: Des copeaux de P.taeda ont ete traites par cinq souches de Ceriporiopsis subvermispora pendant quatre semaines avant mise en pâte mecanique sur raffineur. Les pertes de poids des copeaux lors du traitement fongique ont ete de 4 a 7%. La consommation d'energie lors du defibrage et du raffinage a diminue de 21 a 37%. Les resistances a l'eclatement et au dechirement ont ete ameliorees respectivement de 33-46% et de 47-60%. La resistance a la traction n'a pas ete modifiee, de meme que l'opacite. La blancheur et le coefficient de diffusion de la lumiere ont ete diminues.

77 citations


"Biomechanical Pulping of Loblolly P..." refers methods in this paper

  • ...The rotating solid drum and stationary tray bioreactor are illustrated and described in previous publications (Akhtar et al. 1992; Leatham et al. 1990 a,b; Myers et al 1988)....

    [...]

Journal Article
TL;DR: The authors examined l'influence of ce pretraitement sur l'energie requise pour le raffinage and sur les proprietes mecaniques et optiques des pâtes.
Abstract: Des copeaux de plusieurs especes de bois feuillus et resineux ont ete pretraites par des champignons de la pourriture blanche (Ceriporiopsis subvermispora et Phanerochaete chrysosporium) avant traitement sur raffineur a disques. On examine l'influence de ce pretraitement sur l'energie requise pour le raffinage et sur les proprietes mecaniques et optiques des pâtes.

67 citations


"Biomechanical Pulping of Loblolly P..." refers background in this paper

  • ...The disadvantages of mechanical pulping processes are the primary reasons for evaluating the potential of using fungal treatments prior to mechanical pulping (biomechanical pulping) (Akamatsu et al. 1984; Ander and Eriksson 1975; Setliff et al. 1990), We have achieved promising results with a nonoptimized bench-scale process that uses selected white-rot fungi to treat wood chips prior to refiner mechanical pulping (Leatham et al....

    [...]

Journal Article
TL;DR: In this article, the effect of two white-rot fungi (Phanerochaete chrysosporium and Dichomitus squalens) prior to refiner mechanical pulping was studied.
Abstract: Pretreatment of wood chips with lignin-degrading fungi can improve the strength properties of unbleached refiner mechanical pulps. We studied the effect of two white-rot fungi (Phanerochaete chrysosporium and Dichomitus squalens) prior to refiner mechanical pulping. Strength and optical properties were compared in handsheets prepared from mechanical pulp of treated and untreated wood chips. Both fungal pretreatments resulted in handsheet strength properties better than the control when compared at an equivalent freeness. Fungal pretreatments decreased brightness and light-scattering coefficients but did not adversely affect opacity. Brightness of fungus pretreated pulps was restored to that of the control by use of hydrogen peroxide bleaching. Lignin content of the chips was reduced by the fungal pretreatments.

58 citations


"Biomechanical Pulping of Loblolly P..." refers background in this paper

  • ...However, the pulps obtained from the fungus-treated aspen wood chips responded well to peroxide bleaching (Myers et al. 1988)....

    [...]

Journal Article
TL;DR: It is reported that four-week-long treatment with white-rot fungi in a stationary wire tray bioreactor resulted in at least 35% energy savings for pulping chips to 100 mL CSF in a 300-mm-diameter disc refiner.
Abstract: Besides increasing paper strength, fungal treatments can also reduce the electrical energy needed for fiberizing chips during mechanical pulping. Fungal species, chip movement, and treatment duration affected the extent of energy savings. This paper reports that four-week-long treatment with white-rot fungi, including Phlebia species or Pholiota mutabilis, in a stationary wire tray bioreactor resulted in at least 35% energy savings for pulping chips to 100 mL CSF in a 300-mm-diameter disc refiner. With Phanerochaete chrysosporium in a rotating-drum bioreactor, the optimal treatment duration was four weeks. Treatment with a brown-rot fungus also resulted in energy savings. Over the range of fungi and conditions tested, neither chip weight loss nor lignin loss correlated with energy savings. Some treatments giving the least chip weight loss ({lt}5%) saved the most energy. Wood modifications responsible for energy savings differed from those that increased strength. Treatments that saved the most energy did not necessarily give the highest strength properties.

57 citations