Microbial and Enzymatic Degradation of Wood and Wood Components

413 Pages·1990·15.205 MB·English

by  Karl-Erik L. Eriksson, Robert A. Blanchette, Paul Ander (auth.)

Springer Series in Wood Science
Editor: T. E. Timell
M. H. Zimmermann
Xylem Structure and the Ascent of Sap (1983)
J.E Siau
'fiansport Processes in Wood (1984)
R.R. Archer
Growth Stresses and Strains in Trees (1986)
W.E. Hillis
Heartwood and Tree Exudates (1987)
S. Carlquist
Comparative Wood Anatomy (1988)
L. W. Roberts/P.B. Gahan/R. Aloni
Vascular Differentiation and Plant Growth Regulators (1988)
C. Skaar
Wood-Water Relations (1988)
J.M. Harris
Spiral Grain and Wave Phenomena in Wood Formation (1989)
B. J. Zobel I J. P. van Buijtenen
Wood Variation (1989)
P. Hakkila
Utilization of Residual Forest Biomass (1989)
J.W. Rowe
Natural Products of Woody Plants (1989)
K.-E. L. Eriksson / R. A. Blanchette / P. Ander
Microhial and Enzymatic Degradation of Wood and
Wood Components (1990)
K.-E. L. Eriksson R. A. Blanchette P. Ander
Microbial and Enzymatic
Degradation of
Wood and Wood Components
With 173 Figures
Springer-Verlag Berlin Heidelberg New York
London Paris Tokyo Hong Kong
KARL-ERIK L. ERIKSSON
The University of Georgia, Franklin College of Arts & Sciences,
Department of Biochemistry, Athens, GA 30602, USA
ROBElIT A. BLANCHETTE
University of Minnesota, Department of Plant Pathology, 495 Borlaug Hall,
1991 Buford Circle, St. Paul, MN 55108, USA
PAUL ANDER
STFI, Swedish Pulp and Paper Research Institute, Box 5604, S-11486 Stockholm,
Sweden
Series Editor:
T.E. TIMELL
State University of New York, College of Environmental, Science and Forestry,
Syracuse, NY 13210, USA
Cover: Transverse section of Pinus lambertiana wood. Courtesy of Dr. Carl de Zeeuw,
SUNY College of Environmental Science and Forestry, Syracuse, New York
ISBN-13: 978-3-642-46689-2 e-ISBN-13: 978-3-642-46687-8
DOl: 10.1007/978-3-642-46687-8
Library of Congress Cataloging-in-Publication Data
Eriksson, Karl-Erik. L. Microbial and enzymatic degradation of wood and wood components / K.-E. L.
Eriksson, R. A. Blanchette, P. Ander. p. cm. -
(Springer series in wood science)
ISBN-13: 978-3-642-46689-2
1. Wood - Deterioration. 2. Wood-decaying fungi. 3. Cellulose - Biodegradation. 4. Microbial metabolism.
1. Blanchette, R.A. (Robert A.) II. Ander, P. (Paul), 1941- . III. Title. IV. Series.
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Softcover reprint of the hardcover 1st edition 1990
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Preface
The oil crisis during the 1970s turned interest towards the utilization of
renewable resources and towards lignocellulosics in particular. The 1970s were
also the cradle period of biotechnology, and the years when biotechnical
utilization of lignocellulosic waste from agriculture and forestry gained priori
ty. This was a logical conclusion since one of nature's most important biologi
cal reactions is the conversion of wood and other lignocellulosic materials to
carbon dioxide, water and humic substances. However, while biotechnology in
other areas like medicine and pharmacology concerned production of expen
sive products on a small scale, biotechnical utilization and conversion of ligno
cellulosics meant production of inexpensive products on a large scale.
Biotechnical utilization of lignocellulosic materials is therefore a very difficult
task, and the commercial utilization of this technology has not progressed as
rapidly as one would have desired. One reason for this was the lack of basic
knowledge of enzyme mechanisms involved in the degradation and conversion
of wood, other lignocellulosics and their individual components. There are
also risks associated with initiating a technical development before a stable
platform of knowledge is available. Several of the projects started with en
thusiasm have therefore suffered some loss of interest. Also contributing to
this failing interest is the fact that the oil crisis at the time was not a real one.
At present, nobody predicts a rapid exhaustion of the oil resources and fuel
production from lignocellulosics is no longer a high priority.
The massive amount of effort devoted over the past few decades to a better
understanding of the mechanisms of the degradation of wood and wood com
ponents provides a vast literature base that is essential for successful
biotechnological utilization of lignocellulosic materials. To an academic scien
tist involved in these investigations, it is clear that these research investments
have been a dazzling success. We hope that this book will demonstrate how,
from the mid-1970s, this enormous library of knowledge has accumulated. It
has been a complicated and difficult task to accomplish, and many countries,
laboratories and scientists have been involved. This book is meant to serve as
a source where this knowledge is combined in an understandable way.
This collation will hopefully provide important basic information of value
to those interested in the biotechnological utilization of lignocellulosic materi
als. It should also be of interest to individuals working in the fields of forestry
and forest products, botany, microbiology, mycology, ecology and biochemis
try. I( begins with a description of wood morphology and how wood com
ponents ate decayed by different microorganisms, particularly by wood-rotting
fungi. Most of this knowledge has been gained through electron microscopy
studies. The chapter on cellulose describes the different mechanisms by which
VI Preface
cellulose is degraded by different fungi and bacteria. It is evident that very
rapid progress has been made in this area. It also turns out that degradation
of the heteropolysaccharides, the hemicelluloses, is a more complex matter
than had been expected and many different enzymes are involved in their con
version. The understanding of the mechanisms of lignin degradation has been
particularly rapid, although a concerted research effort in this area did not
really begin until 1978. The understanding of the physiological requirements
and the enzyme mechanisms for the conversion of the lignin polymer into
water-soluble degradation products will ultimately contribute to better pro
cesses for delignification and bleaching. Eventually, delignification will be car
ried out· in a biomimetic way, i.e. catalyzed by low molecular mass organic
compounds mimicking the ligninolytic peroxidases and other enzymes essen
tial for the depolymerization process.
Acknowledgements
Many people have been involved in this production and we wish to thank in
particular: Tore E. Timell, Editor of this series, for his valuble help and advice,
for spreading good will and for fast and efficient handling of all questions
relating to this project. Barbro Almqvist, Berit Broden and Marian Farrow for
skillful and dedicated typing of the manuscript. Sven Rasmusson, The
Troedsson Library, STFI for valuable help with the collection of literature in
formation. Andre Abad, Todd Burnes, Kory Cease, Lewis Otjen and Mike
Carlson for technical assistance and Malcolm Brown, Jr., John Buswell, Ron
Crawford, Debby Delmer, Kent Kirk, Jonathan Knowles, Matti Linko and
G6ran Pettersson for reading certain parts of the book.
Robert A. Blanchette has been mainly responsible for Chapter 1, Karl-Erik
L. Eriksson for Chapters 2 and 3, and Paul Ander for Chapter 4.
Also I would like to thank the Swedish Pulp and Paper Research Institute
for financial support and facilities for the period during which parts of this
book were written.
Athens, January 1990 K.-E. L. Eriksson
Contents
1 Morphological Aspects of Wood Degradation by Fungi and
Bacteria ................................................... .
1.1 Morphology of Wood and Wood Components ............. 1
1.2 Wood Degradation by White-Rot Fungi. . .. . . . . . . . . . . . . . . . 20
1.3 Wood Degradation by Brown-Rot Fungi. . .. . . . . . . . .. . . . . . . 43
1.4 Wood Degradation by Soft-Rot Fungi. . . . .. . . . . . . . . . . . .. . . 56
1.5 Wood Degradation by Bacteria . . . . . . . . . . . . . . . . . . . . . . . . . . . 72
2 Biodegradation of Cellulose. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89
2.1 The Structure and Biosynthesis of Cellulose ............... 90
2.1.1 The Chemical Structure of Cellulose . . . . . . . . . . . . . . . . . . . . . . 90
2.1.2 Cellulose Biosynthesis: Biochemical Studies. . . . . . . . . . . . . . . . 91
2.1.3 The Cellulose Microfibril. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93
2.2 Cellulolytic Fungi. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99
2.3 Cellulolytic Enzymes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102
2.3.1 The Old Concept ................................ , . . . . . . 102
2.3.2 Hydrolytic Enzymes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105
2.3.3 Oxidative Enzymes ..................................... 105
2.3.4 Phosphorolytic Enzymes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105
2.4 Assay of Enzymes Participating in Cellulose Degradation. . . . 106
2.4.1 Endo-l,4-p-Glucanase Activity ........................... 108
2.4.2 Exo-l,4-p-Glucanase Activity. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109
2.4.3 l,4-p-Glucosidase Activity ........ . . . . . . . . . . . . . . . . . . . . . . . 111
2.4.4 Oxidative Enzymes ..................................... 112
2.4.5 Phosphorolytic Enzymes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112
2.5 Cellulose Degradation by White-Rot, Brown-Rot, Soft-Rot,
and Anaerobic Fungi. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113
2.5.1 White-Rot Fungi ....................................... 113
2.5.2 Brown-Rot Fungi. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120
2.5.3 Soft-Rot Fungi. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 124
2.5.4 Anaerobic Fungi. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 135
2.6 Cellulose Degradation by Bacteria. . . . . . . . . . . . . . . . . . . . . . . . 137
2.6.1 Aerobic Bacteria. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 138
2.6.2 Anaerobic Bacteria ..................................... 151
2.7 Regulation of Cellulase Synthesis. . . . . . . . . . . . . . . . . . . . . . . . . 159
2.8 Synergistic Mechanisms Involved in Cellulose Degradation . . . 164
VIII Contents
2.9 Examples of Applications of Cellulolytic Microorganisms and
Their Enzymes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 174
2.9.1 Fermentation of Lignocellulosic Materials to Protein. . . . . . . . 175
2.9.2 Enzymatic Saccharification of Lignocellulosic Materials for
Ethanol Production. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 177
3 Biodegradation of Hemicelluloses. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 181
3.1 The Structures of Hemicelluloses . . . . . . . . . . . . . . . . . . . . . . . . . 181
3.1.1 Softwood Hemicelluloses . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . 181
3.1.2 Hardwood Hemicelluloses ............................... 183
3.2 Biosynthesis of Hemicelluloses . . . . . . . . . . . . . . . . . . . . . . . . . . . 185
3.3 Xylanolytic Enzymes..... . .. . . . .. .. .. .. .. . . . .. .. .... .. .. 186
3.3.1 Endo-l,4-p-o-Xylanases ................................. 187
3.3.2 l,4-p-o-Xylosidases ..................................... 198
3.3.3 a-Arabinosidase . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 203
3.3.4 a-o-Glucuronidase. . .. .. .. . ... . . . .. . .. . . . .. . . . . ... .. .. .. 206
3.3.5 Acetyl(Xylan) Esterase .................................. 210
3.4 Mannan-Degrading Enzymes. .......................... .. 213
3.4.1 Endo-1,4-p-o-Mannanases . . . .. . .. .... . . .. .. . . . .... .. . ... 214
3.4.2 1,4-p-o-Mannosidase . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 218
3.4.3 a-Galactosidase ........................................ 221
3.5 Examples of Applications of Hemicellulolytic Organisms and
Their Enzymes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 222
4 Biodegradation of Lignin. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 225
4.1 Biosynthesis and Structure of Lignin. . . . . . . . . . . . . . . . . . . . .. 226
4.2 Lignin Preparations and Methods for Studying Lignin
Biodegradation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 231
4.3 Lignin Degradation by White-Rot Fungi. . . . . . . . . . . . . . . . . .. 234
4.3.1 Physiological Demands, Secondary Metabolism, and Veratryl
Alcohol Production in White-Rot Fungi.... .. ... ........ .. 234
4.3.2 Influence of Nitrogen on Secondary Metabolism and Lignin
Degradation ........................................... 237
4.3.3 Influence of Carbon Source on Lignin Degradation. . . . . . . . . 242
4.3.4 Influence of Agitation and Other Cultivation Conditions on
Lignin Degradation and Ligninase Production. . . . . . . . . . . . . . 244
4.3.5 Influence of Oxygen and Carbon Dioxide on Lignin
Degradation. Anaerobic Degradation of Lignin and Related
Compounds. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 247
4.4 Chemistry of Lignin Degraded by White-Rot Fungi.. ... .. .. 249
4.5 Biochemistry of Lignin Degradation ...................... 253
4.5.1 Oxygen Radicals and Lignin Degradation. . . . . . . . . . . . . . . . .. 253
Contents IX
4.5.2 The Phenoloxidases Laccase and Peroxidase Including
Manganese-Dependent Pexoxidase ........................ 255
4.5.3 Ligninase/Lignin Peroxidase ............................. 270
4.5.4 Biomimetic Oxidation of Lignin Models. . . . . . . . . . . . . . . . . . . 292
4.5.5 H 0 -Producing Enzymes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 294
2 2
4.5.6 Quinone-Reducing Enzymes. . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 297
4.5.7 Cleavage of Methoxyl Groups by Wood-Rotting Fungi. . . . . . 302
4.6 Metabolism of Monomeric Lignin-Related Compounds. . . . .. 307
4.7 Lignin Degradation by Brown-Rot, Soft-Rot, and Other
Fungi .. " ... , ..... " ..... , .. . . . .. .. .. .. .. .. . . . .. . . . . .. 312
4.7.1 Brown-Rot Fungi ... " ..... , .. . . ..... .. ... . .. . .. .. .. .. .. 312
4.7.2 Soft-Rot Fungi. . . . . .. . . . . . . . . . . . .. . . . . . . . . . . . . .. . . . . . .. 316
4.7.3 Other Fungi ........................................... 318
4.8 Lignin Degradation by Bacteria .......................... 319
4.8.1 Actinomycetes.......................................... 319
4.8.2 Other Bacteria ......................................... 323
4.9 Potential Applications of White-Rot Fungi. . . . . . . . . . . . . . . .. 325
4.9.1 Biopulping and Biomechanical Pulping. . . . . . . . . . . . . . . . . . . . 325
4.9.2 Treatment of Wood and Straw to Produce Feed and Food. .. 329
4.9.3 Treatment of Spent Kraft Bleach Liquors. . . . . . . . . . . . . . . . .. 329
4.9.4 By-Products from Lignin. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 332
4.10 Some Examples of Future Research Possibilities. . . . . . . . . . . . 332
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 335
Subject Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 399
Chapter 1
Morphological Aspects of Wood Degradation by Fungi
and Bacteria
1.1 Morphology of Wood and Wood Components
The structure and chemical composition of wood have a significant influence
on its degradation by microorganisms and the resulting patterns of decay. The
type of cell, chemical composition, and cell wall morphology may all govern
the effects of enzymes on the woody substrate. Wood is made up largely of cel
lulose, lignin, and hemicellulose in various proportions (Table 1.1). The lignin
content of angiosperms is generally lower than that of gymnosperms. Differ
ences in the major hemicellulose present are reflected in the xylose and man
nose content (Thble 1.1), which represents glucuronoxylan in hardwoods and
galactoglucomannans in softwoods. Large differences in the chemical compo
nents exist among various woods (Pengel and Wegener 1983) and the composi
tion of different types of cells within wood may also vary (Saka and Goring
1985). The type of lignin found in hardwoods and softwoods is also different.
Table 1.1. Percent lignin and wood sugar residues in sapwood of various tree species
Wood Percent
Lignin" Glucoseb Xyloseb Mannoseb
Angiosperms
Acacia koa 27.3 45.6 18.6 1.7
Acer saccharum 24.4 46.2 17.2 2.4
Alnus rubra 24.6 47.0 17.6 0.4
Betula papyri/era 19.0 44.9 24.3 2.1
B. verrucosa 21.7 35.1 20.7 0.9
Populus tremuloides 22.0 46.2 18.9 1.6
Quercus rubra 24.5 41.6 23.5 3.0
Tilia americana 21.5 43.9 16.1 0.3
Ulmus americana 23.6 55.8 16.0 3.1
Gymnosperms
Abies balsamea 29.1 46.6 5.6 11.7
Picea abies 27.1 41.6 5.2 13.6
P. mariana 26.6 49.0 7.3 13.8
Pinus banksiana 29.9 44.6 8.4 10.0
P. resinosa 27.9 44.9 8.4 12.3
P. strobus 28.1 48.2 6.0 15.6
P. sylvestris 30.0 38.3 6.5 11.1
Tsuga canadensis 32.3 47.9 4.2 13.8
a Sulfuric acid lignin by the method of Effland (1977).
b HPLC analysis using method of Pettersen et al. (1985).