scholarly journals Depolymerization and conversion of lignin to value-added bioproducts by microbial and enzymatic catalysis

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Caihong Weng ◽  
Xiaowei Peng ◽  
Yejun Han

AbstractLignin, the most abundant renewable aromatic compound in nature, is an excellent feedstock for value-added bioproducts manufacturing; while the intrinsic heterogeneity and recalcitrance of which hindered the efficient lignin biorefinery and utilization. Compared with chemical processing, bioprocessing with microbial and enzymatic catalysis is a clean and efficient method for lignin depolymerization and conversion. Generally, lignin bioprocessing involves lignin decomposition to lignin-based aromatics via extracellular microbial enzymes and further converted to value-added bioproducts through microbial metabolism. In the review, the most recent advances in degradation and conversion of lignin to value-added bioproducts catalyzed by microbes and enzymes were summarized. The lignin-degrading microorganisms of white-rot fungi, brown-rot fungi, soft-rot fungi, and bacteria under aerobic and anaerobic conditions were comparatively analyzed. The catalytic metabolism of the microbial lignin-degrading enzymes of laccase, lignin peroxidase, manganese peroxidase, biphenyl bond cleavage enzyme, versatile peroxidase, and β-etherize was discussed. The microbial metabolic process of H-lignin, G-lignin, S-lignin based derivatives, protocatechuic acid, and catechol was reviewed. Lignin was depolymerized to lignin-derived aromatic compounds by the secreted enzymes of fungi and bacteria, and the aromatics were converted to value-added compounds through microbial catalysis and metabolic engineering. The review also proposes new insights for future work to overcome the recalcitrance of lignin and convert it to value-added bioproducts by microbial and enzymatic catalysis.

Holzforschung ◽  
2013 ◽  
Vol 67 (7) ◽  
pp. 825-832 ◽  
Author(s):  
Anna-Kaisa Anttila ◽  
Anna Maria Pirttilä ◽  
Hely Häggman ◽  
Anni Harju ◽  
Martti Venäläinen ◽  
...  

Abstract In the last decades, many wood preservatives have been prohibited for their ecotoxicity. The present article is focusing on the conifer-derived condensed tannins as environment-friendly options for the substitution of artificial wood preservatives. Eight different tannin fractions were extracted from spruce cones, spruce barks, and pine cones. The parameters of tannin extraction, such as the methods of purification and concentration of active components in the extracts, have been investigated. The cone and bark extracts were tested for the growth inhibition of eight brown-rot fungi, three white-rot fungi, and four soft-rot fungi in liquid cultures. The cone tannins provided a more efficient fungal growth inhibition than bark tannins. Purification increased the antifungal properties of the extracts. The growth of brown-rot fungi was inhibited by the tannins already at low concentrations. However, the extracts were not effective against the white-rot or soft-rot fungi. More investigation is needed concerning the tannin source and the purification procedure of the extracts before tannins can be considered as an ecologically benign wood preservative.


Author(s):  
Aydan Atalar ◽  
Nurcan Çetinkaya

The efforts to break down the lignocellulosic complex found in the cell wall of straws, besides digestible cellulose and hemicellulose by rumen fermentation, improvement of straw digestibility by the degradation of indigestible lignin fraction of complex by using of biotechnological methods is one of the focus areas of animal nutritionists in recent years. Biological method sare prefer redover other methods due to the environmental friendliness. In the biological treatment methods of lignocellulosic complex, biodiversity of bacteria, enzymes and fungi gives opportunity to select lignin degrading species. Mycobacterium, Arthrobacter and Flavobacterium genre bacteria are used to degrade lignin by bacterial treatment. Lignocellulolytic enzymes isolated from different varieties of fungi are used in enzyme treatment. There are 3 genres of fungus that are white, Brown and soft rot in fungal treatments. Brown rot fungi prefer ably attack cellulose and hemicelluloses, but not lignin. White rot fungi attack the lignin and break up lignol bonds and aromatic ring. White rot fungi break down polysaccharides with hydrolytic enzymes such as cellulase, xylanase, and lignin with oxidative ligninolytic enzymes such as lignin peroxidase and laccase. Because of the fact that the microorganisms that can break down the lignocellulosic materials are the fungi and the cost is low, the application of white rot fungi is possible. In this paper, improvement the lignocellulosic comlex digestibility of straw by biological treatment with the advantage of biodiversity is discussed.


Author(s):  
Aydan Atalar ◽  
Nurcan Çetinkaya

The efforts to break down the lignocellulosic complex found in the cell wall of straws, besides digestible cellulose and hemicellulose by rumen fermentation, improvement of straw digestibility by the degradation of indigestible lignin fraction of complex by using of biotechnological methods is one of the focus areas of animal nutritionists in recent years. Biological method sare prefer redover other methods due to the environmental friendliness. In the biological treatment methods of lignocellulosic complex, biodiversity of bacteria, enzymes and fungi gives opportunity to select lignin degrading species. Mycobacterium, Arthrobacter and Flavobacterium genre bacteria are used to degrade lignin by bacterial treatment. Lignocellulolytic enzymes isolated from different varieties of fungi are used in enzyme treatment. There are 3 genres of fungus that are white, Brown and soft rot in fungal treatments. Brown rot fungi prefer ably attack cellulose and hemicelluloses, but not lignin. White rot fungi attack the lignin and break up lignol bonds and aromatic ring. White rot fungi break down polysaccharides with hydrolytic enzymes such as cellulase, xylanase, and lignin with oxidative ligninolytic enzymes such as lignin peroxidase and laccase. Because of the fact that the microorganisms that can break down the lignocellulosic materials are the fungi and the cost is low, the application of white rot fungi is possible. In this paper, improvement the lignocellulosic comlex digestibility of straw by biological treatment with the advantage of biodiversity is discussed.


2010 ◽  
Vol 36 (2) ◽  
pp. 81-85
Author(s):  
Kahoru Matsumoto ◽  
Futoshi Ishiguri ◽  
Kazuya Iizuka ◽  
Shinso Yokota ◽  
Naoto Habu ◽  
...  

To obtain the basic information needed to estimate the degree of decay from compressive strength measured using a Fractometer (CS), relationships between CS and the contents of chemical components were analyzed for Magnolia wood decayed by three types fungi (brown rot, white rot, and soft rot fungi) at various decay levels. Weight loss ratio was significantly, negatively correlated with CS in woods decayed by brown rot and white rot fungi. In addition, a relatively high correlation coefficient was recognized between CS and holocellulose or α-cellulose content, except for wood decayed by soft rot fungus. The results obtained showed that Fractometer can detect the decrease of CS at relatively early stage of decay.


1983 ◽  
Vol 61 (1) ◽  
pp. 171-173 ◽  
Author(s):  
E. L. Schmidt ◽  
D. W. French

Successive collections of basidiospores, produced in culture from the same hymenial areas of four species of wood decay fungi, were tested for spore germination percentage on malt extract agar under controlled conditions. Spores from white rot fungi retained high germination levels after 5 weeks of spore production, but germination averages for brown rot fungi decreased by more than 50%. Such variation should be considered in wood pathology research using spore germination bioassay.


Holzforschung ◽  
2008 ◽  
Vol 62 (6) ◽  
Author(s):  
Jonathan S. Schilling ◽  
Kaitlyn M. Bissonnette

AbstractWood-degrading fungi commonly grow in contact with calcium (Ca)-containing building materials and may import Ca and iron (Fe) from soil into forest woody debris. For brown rot fungi, imported Ca2+may neutralize oxalate, while Fe3+may facilitate Fenton-based degradation mechanisms. We previously demonstrated, in two independent trials, that degradation of spruce by wood-degrading fungi was not promoted when Ca or Fe were imported from gypsum or metallic Fe, respectively. Here, we tested pine wood with lower endogenous Ca than the spruce blocks used in prior experiments, and included a pure gypsum treatment and one amended with 1% with FeSO4. Electron microscopy with microanalysis verified that brown rot fungiSerpula himantioidesandGloeophyllum trabeumand the white rot fungusIrpex lacteusgrew on gypsum and produced iron-free Ca-oxalate crystals away from the gypsum surface. Wood cation analysis verified significant Fe import by both brown rot isolates in Fe-containing treatments. Wood degradation was highest in Fe-gypsum-containing treatments for all three fungi, although only wood degraded byI. lacteushad significant Ca import. We suggest that Fe impurities may not exacerbate brown rot, and that both brown and white rot fungi may utilize Ca-containing materials.


Holzforschung ◽  
1999 ◽  
Vol 53 (5) ◽  
pp. 491-497 ◽  
Author(s):  
Catherine C. Celimene ◽  
Jessie A. Micales ◽  
Leslie Ferge ◽  
Raymond A. Young

Summary Three stilbenes, pinosylvin (PS), pinosylvin monomethyl ether (PSM) and pinosylvin dimethyl ether (PSD), were extracted from white spruce (Picea glauca), jack pine (Pinus banksiana), and red pine (Pinus resinosa) pine cones, and their structures were confirmed by spectroscopic and chromatographic (HPLC, GC/MS, NMR and FTIR) analysis. PS, PSM, PSD or a 1:1:1 mixture of these stilbenes at concentrations of 0.1 % and 1.0 % were examined for their fungal inhibitory activity by two bioassay methods. Growth of white-rot fungi (Trametes versicolor and Phanerochaete chrysosporium), and brown-rot fungi (Neolentinus lepideus, Gloeophyllum trabeum and Postia placenta) on agar media in the presence of each of the stilbenes or a 1:1:1 mixture inhibited growth of white-rot fungi, but slightly stimulated growth of brown-rot fungi. Soil-block assays, conditions more representative of those found in nature, did not correlate with those from the screening on agar media. PS, PSM, PSD or a 1:1:1 mixture of the three compounds at concentrations of 0.1 % and 1.0 % did not impart any significant decay resistance to white-rot fungi inoculated on a hardwood (Red maple). However under the same conditions, decay resistance was observed against brown-rot fungi on a softwood (Southern yellow pine). It appears that stilbenes at least partially contribute to wood decay resistance against brown-rot fungi.


BioResources ◽  
2021 ◽  
Vol 16 (2) ◽  
pp. 3978-3990
Author(s):  
Meng Li ◽  
Zhinan Wang ◽  
Jin Sun ◽  
Wanjuan Chen ◽  
Xianfeng Hu ◽  
...  

The thermogravimetric properties and chemical characterization of rice straw (RS) pretreated by mixed culture of white-rot fungi Phanerochaete chrysosporium (P. chrysosporium) and brown-rot fungi Gloeophyllum trabeum (G. trabeum) were investigated. The mixed fungal pretreatment showed a synergistic effect, which resulted in an energy-efficient pyrolysis of pretreated rice straw. The differences in thermochemical conversion of rice straw before and after fungal pretreatment were investigated using thermogravimetric analysis and the Flynn–Wall–Ozawa (FWO) method. Furthermore, the pretreated samples were also analyzed by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and scanning electron microscopy (SEM) to illuminate the changes in chemical composition and pyrolysis behavior. Compared to single fungal pretreatment, the mixed fungal pretreatment worked better and exhibited great potential in biomass pyrolysis.


Holzforschung ◽  
2002 ◽  
Vol 56 (3) ◽  
pp. 229-238 ◽  
Author(s):  
M. Humar ◽  
M. Petrič ◽  
F. Pohleven ◽  
M. Šentjurc ◽  
P. Kalan

SummaryThe tolerance of various fungi against copper was examined. For this purpose, we impregnated Norway spruce (Picea abies) specimens with two different aqueous solutions: copper(II) octanoate with ethanolamine or copper(II) sulfate (cCu= 1.0 × 10−2mol/l). Impregnated and unimpregnated test specimens were then exposed to brown rot fungiAntrodia vaillantiiandGloeophyllum trabeumor to white-rot fungiSchizophyllum communeandTrametes versicolor. After 2, 4, 6 and 12 weeks of exposure Electron Paramagnetic Resonance, Atomic Absorption Spectroscopy and mass loss measurements were performed. The results indicate thatA. vaillantii, G. trabeumandT. versicolortransform copper(II) sulfate in wood into non-soluble, and therefore non-toxic, copper oxalate. The intensity of this reaction depends on the amount of excreted oxalic acid and was the highest forA. vaillantiiand the lowest forT. versicolor. In the presence of ethanolamine, formation of insoluble copper oxalate was not possible and therefore, decay could not proceed. The major portion of copper remained in the wood and only minor amounts were in some cases translocated into nutrient media.


Microbiology ◽  
1984 ◽  
Vol 130 (10) ◽  
pp. 2457-2464 ◽  
Author(s):  
K.-E. Eriksson ◽  
J. K. Gupta ◽  
A. Nishida ◽  
M. Rao

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