Evaluation of novel wood-rotting polypores and corticioid fungi for the decay and biopulping of Norway spruce (Picea abies) wood

doi:10.1016/j.enzmictec.2003.10.014

Enzyme and Microbial Technology

Volume 34, Issues 3–4, 1 March 2004, Pages 255-263

https://doi.org/10.1016/j.enzmictec.2003.10.014 Get rights and content

Abstract

Pre-treatment of wood chips with white-rot fungi (i.e. biopulping) has previously been shown to decrease the energy consumption in mechanical pulping. In this study, promising novel fungal isolates were found for biopulping of Norway spruce (Picea abies). Three hundred fungal isolates were evaluated by agar plate tests. According to the results, 86 isolates were chosen to a wood block decay test. The characteristics of the fungal attack and the wood decay were studied and chemical analyses of cellulose, lignin, and hemicelluloses in the residual wood were performed. The results showed both interspecies and intraspecies variations in the degradation patterns of these compounds. After a 10-week incubation period, 17 of the novel white-rot strains showed selective lignin degrading ability, based on the chemical analyses. Some of these lignin-selective strains also grew well even at +37 °C. The selectivity value, i.e. the lignin/cellulose loss ratio, was higher for 11 of the studied strains compared to the widely studied Ceriporiopsis subvermispora. In this study, Physisporinus rivulosus T241i was shown to be a superior novel isolate for softwood biopulping applications based on its growth characteristics through a wide temperature range and its selectivity towards lignin.

Introduction

White-rot fungi are the only organisms able to efficiently degrade lignin [1], [2], the recalcitrant organic polymer that makes the use of wood as a source of cellulose fibers challenging. During recent years, incubation of wood chips with white-rot basidiomycetous fungi has been studied as a pre-treatment step in mechanical or chemical pulping. Fungal growth in wood chips results in concomitant changes in the chemical structure of wood, which facilitates fiber separation, thus saving electrical energy and improving strength properties of the final product [3]. Some fungal species remove lignin more efficiently than other wood components, which is designated as selective lignin degradation. Selective removal of lignin has been found to be beneficial in the downstream processes in mechanical pulping [4], [5].

In most biopulping studies, aspen (Populus spp.) or pine (Pinus spp.) wood chips have been used as wood material [6]. The fungal isolate, wood substrate, and ecophysiological factors affect the fungal growth and wood degradation pattern [7]. Although Norway spruce (Picea abies) is the main raw material in mechanical pulping in Northern Europe, it has only been used in a few studies as a substrate [8], [9], [10]. In order to find novel efficient strains of white-rot fungi, which will remove lignin from Norway spruce without significantly affecting cellulose fibers, the strain-specific wood degradation patterns were evaluated. A deeper understanding of the behavior of currently known biopulping fungi, such as Ceriporiopsis subvermispora [6], [11] and Phlebia gigantea [12] also on spruce wood was obtained. Phloroglucinol staining and light microscopy was used to evaluate the spruce wood decay patterns of 86 strains, which were selected among 300 isolates according to the results in a primary screening in agar plates. Lignin content of the decayed wood blocks was determined by the Klason method, and cellulose and hemicellulose content by gas chromatography after acid hydrolysis or after acid methanolysis, respectively. Five fungi removed over two times more lignin than cellulose in 10 weeks. One of these strains, Physisporinus rivulosus T241i (syn. Ceriporiopsis rivulosa, Poria albipellucida, Poria rivulosa), was also thermotolerant, which indicates that it has potential for softwood biopulping.

Section snippets

Fungal strains

Altogether 301 isolates and control strains of wood-rotting or litter-decomposing fungi were screened to find the most promising fungi for softwood pre-treatment. Most of the strains (250) were collected during the years 1998–1999 from various parts of Finland. The strains (Table 1) were isolated either from fruiting bodies or from basidiospores (denoted as the letter “i” in the strain number). According to the results from the primary screening, 86 fungal isolates were selected for the wood

The first screening step

Approximately 100 of the tested strains decolorized Poly R-478 efficiently in one or more test plates that contained either glucose or cellobiose. Forty strains decolorized the dye effectively in every test plate, regardless of the concentration or the type of the carbon source (data not shown). One-third of the strains were able to grow at 37 °C, although most of these strains grew faster at 28 °C. The elevated temperature (37 °C) did not inhibit the growth of 22 strains, including several

Discussion

Our results show that lignin selectivity on spruce wood is rare among white-rot fungi, especially in combination with other fungal properties regarded beneficial in biopulping. In addition to lignin selectivity, these characteristics include fast growth rate, thermotolerance and lignin modification ability during the early phase of growth on woody substrates. Only 17 out of the 86 strains studied showed the selectivity index higher than 1.0 on spruce. The calculated selectivity value of eleven

Acknowledgements

We thank for the skillful technical assistance of Mr. Mika Kalsi and Lic. (Agr. & For.) Beata Kluczek-Turpeinen. We are grateful to Prof. Yu-Cheng Dai, Dr. Heikki Kotiranta, Prof. Tuomo Niemelä, and Dr. Reijo Penttilä, who identified most of the fungi. This work was part of the consortium “Pre-treatments of wood chips in pulping processes,” projects “Microbial pre-treatments of wood chips” and “Analysis of wood and pulps,” funded by the technology program Wood Wisdom, through the National

References (39)

E de Jong et al.
Isolation and screening of basidiomycetes with high peroxidative activity
Mycol. Res.
(1992)
T Robinson et al.
Studies on the production of enzymes by white-rot fungi for the decolorization of textile dyes
Enzyme Microb. Technol.
(2001)
M.H Gold et al.
Use of polymeric dyes in lignin biodegradation assays
Methods Enzymol
(1988)
T.K Kirk et al.
Production of multiple ligninases by Phanerochaete chrysosporium: effect of selected growth conditions and use of a mutant strain
Enzyme Microb. Technol.
(1986)
T.K Kirk et al.
Enzymatic “combustion”: the microbial degradation of lignin
Annu. Rev. Microbiol.
(1987)
Hatakka A. Biodegradation of lignin. In: Hofrichter M, Steinbüchel A, editors. Biopolymers, vol. 1: Lignin, humic...
Scott GM, Akhtar M, Swaney RE, Houtman CJ. Recent development in biopulping technology at Madison, WI. In: Viikari L,...
R.A Blanchette
Screening wood decayed by white-rot fungi for preferential lignin degradation
Appl. Environ. Microbiol.
(1984)
G.F Leatham et al.
Biomechanical pulping of aspen chips: energy savings resulting from different fungal treatments
TAPPI J.
(1990)
Akhtar M, Blanchette RA, Myers GC, Kirk TK. An overview of biomechanical pulping research. In: Young RA, Akhtar M,...

R.A Blanchette

Delignification by wood-decay fungi

Annu. Rev. Phytopathol.

(1991)

K.-E Eriksson et al.

Properties of pulps from thermomechanical pulping of chips pretreated with fungi

Sven Papperstidn

(1982)

E.C Setliff et al.

Biomechanical pulping with white-rot fungi

TAPPI J.

(1990)

Y Kashino et al.

Biomechanical pulping using white-rot fungus IZU-154

TAPPI J.

(1993)

Scott GM, Akhtar M, Lentz MJ, Swaney RE. Engineering, scale-up and economical aspects of fungal pretreatment of wood...

C.J Behrendt et al.

Biological processing of pine logs for pulp and paper production with Phlebiopsis gigantea

Appl. Environ. Microbiol.

(1997)

M Akhtar et al.

Biomechanical pulping of loblolly pine chips with selected white-rot fungi

Holzforschung

(1993)

R.A Blanchette et al.

Lignin distribution in cell walls of birch wood decayed by white-rot basidiomycetes

Phytopathology

(1987)

A Hatakka et al.

Degradation of $^{14} C$ -labelled poplar wood lignin by selected white-rot fungi

Eur. J. Appl. Microbiol. Biotechnol.

(1983)

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Evaluation of novel wood-rotting polypores and corticioid fungi for the decay and biopulping of Norway spruce (Picea abies) wood

Abstract

Introduction

Section snippets

Fungal strains

The first screening step

Discussion

Acknowledgements

Mycol. Res.

Enzyme Microb. Technol.

Methods Enzymol

Enzyme Microb. Technol.

Enzymatic “combustion”: the microbial degradation of lignin

Annu. Rev. Microbiol.

Screening wood decayed by white-rot fungi for preferential lignin degradation

Appl. Environ. Microbiol.

Biomechanical pulping of aspen chips: energy savings resulting from different fungal treatments

TAPPI J.

Delignification by wood-decay fungi

Annu. Rev. Phytopathol.

Properties of pulps from thermomechanical pulping of chips pretreated with fungi

Sven Papperstidn

Biomechanical pulping with white-rot fungi

TAPPI J.

Biomechanical pulping using white-rot fungus IZU-154

TAPPI J.

Biological processing of pine logs for pulp and paper production with Phlebiopsis gigantea

Appl. Environ. Microbiol.

Biomechanical pulping of loblolly pine chips with selected white-rot fungi

Holzforschung

Lignin distribution in cell walls of birch wood decayed by white-rot basidiomycetes

Phytopathology

Degradation of 14C-labelled poplar wood lignin by selected white-rot fungi

Eur. J. Appl. Microbiol. Biotechnol.

Degradation of $^{14} C$ -labelled poplar wood lignin by selected white-rot fungi