scholarly journals Application of lignocellulolytic fungi for bioethanol production from renewable biomass

2015 ◽  
Vol 69 (6) ◽  
pp. 627-641 ◽  
Author(s):  
Jelena Jovic ◽  
Jelena Pejin ◽  
Suncica Kocic-Tanackov ◽  
Ljiljana Mojovic

Pretreatment is a necessary step in the process of conversion of lignocellulosic biomass to ethanol; by changing the structure of lignocellulose, enhances enzymatic hydrolysis, but, often, it consumes large amounts of energy and/or needs an application of expensive and toxic chemicals, which makes the process economically and ecologically unfavourable. Application of lignocellulolytic fungi (from the class Ascomycetes, Basidiomycetes and Deuteromycetes) is an attractive method for pre-treatment, environmentally friendly and does not require the investment of energy. Fungi produce a wide range of enzymes and chemicals, which, combined in a variety of ways, together successfully degrade lignocellulose, as well as aromatic polymers that share features with lignin. On the basis of material utilization and features of a rotten wood, they are divided in three types of wood-decay fungi: white rot, brown rot and soft rot fungi. White rot fungi are the most efficient lignin degraders in nature and, therefore, have a very important role in carbon recycling from lignified wood. This paper describes fungal mechanisms of lignocellulose degradation. They involve oxidative and hydrolytic mechanisms. Lignin peroxidase, manganese peroxidase, laccase, cellobiose dehydrogenase and enzymes able to catalyze formation of hydroxyl radicals (?OH) such as glyoxal oxidase, pyranose-2-oxidase and aryl-alcohol oxidase are responsible for oxidative processes, while cellulases and hemicellulases are involved in hydrolytic processes. Throughout the production stages, from pre-treatment to fermentation, the possibility of their application in the technology of bioethanol production is presented. Based on previous research, the advantages and disadvantages of biological pre-treatment are pointed out.

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.


2000 ◽  
Vol 66 (11) ◽  
pp. 4725-4734 ◽  
Author(s):  
Claudia A. Jasalavich ◽  
Andrea Ostrofsky ◽  
Jody Jellison

ABSTRACT We have developed a DNA-based assay to reliably detect brown rot and white rot fungi in wood at different stages of decay. DNA, isolated by a series of CTAB (cetyltrimethylammonium bromide) and organic extractions, was amplified by the PCR using published universal primers and basidiomycete-specific primers derived from ribosomal DNA sequences. We surveyed 14 species of wood-decaying basidiomycetes (brown-rot and white-rot fungi), as well as 25 species of wood-inhabiting ascomycetes (pathogens, endophytes, and saprophytes). DNA was isolated from pure cultures of these fungi and also from spruce wood blocks colonized by individual isolates of wood decay basidiomycetes or wood-inhabiting ascomycetes. The primer pair ITS1-F (specific for higher fungi) and ITS4 (universal primer) amplified the internal transcribed spacer region from both ascomycetes and basidiomycetes from both pure culture and wood, as expected. The primer pair ITS1-F (specific for higher fungi) and ITS4-B (specific for basidiomycetes) was shown to reliably detect the presence of wood decay basidiomycetes in both pure culture and wood; ascomycetes were not detected by this primer pair. We detected the presence of decay fungi in wood by PCR before measurable weight loss had occurred to the wood. Basidiomycetes were identified to the species level by restriction fragment length polymorphisms of the internal transcribed spacer region.


Holzforschung ◽  
1999 ◽  
Vol 53 (6) ◽  
pp. 563-568 ◽  
Author(s):  
Frederick Green ◽  
Carol A. Clausen

SummaryHydrolysis of bordered and pinoid pits may be a key event during colonization of wood by decay fungi. Although pits are numerous, studies of pectin-hydrolyzing enzymes in wood decay fungi are scarce, probably because of the relatively low content (less than 4 %) of pectin in wood and because of the primary focus on understanding the degradation of lignified components. Endopolygalacturonase (endo- PG) activity was estimated by cup-plate assay and viscosity reduction of pectin from liquid cultures of fifteen brown-rot and eight white-rot basidiomycetous fungi using sodium polypectate as the carbon source. Oxalic acid was estimated in liquid culture and related to mycelial weight of each fungus. Changes in longitudinal gas permeability of southern pine cores exposed to selected decay fungi in liquid culture were measured to determine the extent of hydrolysis of bordered pits. Twelve of fifteen brown-rot and six of eight white-rot fungi tested were positive for at least one of the polygalacturonase test methods. Accumulation of oxalic acid was detected in thirteen of fifteen brown-rot isolates and none of the white-rot fungi tested. Gas permeability of pine cores increased approximately fourfold among brown-rot fungi tested and eighteenfold among white-rot fungi tested. Scanning electron microscopy revealed bordered pit membrane hydrolysis in cores colonized by white-rot fungi, but only torus damage, weakening and tearing of the pit membranes, was observed in cores exposed to brown-rot fungi. We conclude that both brown- and white-rot decay fungi have the enzymatic capacity to hydrolyze pectin, damage bordered pit membranes, and increase wood permeability during colonization and incipient decay.


Holzforschung ◽  
2012 ◽  
Vol 66 (8) ◽  
pp. 1009-1015 ◽  
Author(s):  
Shyamal C. Ghosh ◽  
Jens Dyckmans ◽  
Holger Militz ◽  
Carsten Mai

Abstract Scots pine (Pinus sylvestris L.) and European beech (Fagus sylvatica L.) wood samples treated with quaternary (quat)- and amino-silicone (QS and AS) solutions of different chain lengths were tested against brown-rot and white-rot fungi as well as with regard to blue stain colonisation. The treatment with short-chained silicones bearing quat and amino functional group reduced the mass loss (ML) by decay fungi at 15% treatment concentration. The release of metabolic heat by decayed samples determined in a microcalorimeter corresponded with the ML of the samples, i.e., samples with high ML produced more heat indicating higher fungal activity. Short-chain ASs reduced the blue staining more strongly than long-chain ones. However, the opposite was true in the case of QS. It was assumed that the combined effect of hydrophobation, cell wall bulking and change of the wood surface energy are responsible for a successful performance of silicone compounds as wood preservatives.


2019 ◽  
Vol 26 (14) ◽  
pp. 2475-2484 ◽  
Author(s):  
Congqiang Zhang ◽  
Heng-Phon Too

Lignocellulose is the most abundant renewable natural resource on earth and has been successfully used for the production of biofuels. A significant challenge is to develop cost-effective, environmentally friendly and efficient processes for the conversion of lignocellulose materials into suitable substrates for biotransformation. A number of approaches have been explored to convert lignocellulose into sugars, e.g. combining chemical pretreatment and enzymatic hydrolysis. In nature, there are organisms that can transform the complex lignocellulose efficiently, such as wood-degrading fungi (brown rot and white rot fungi), bacteria (e.g. Clostridium thermocellum), arthropods (e.g. termite) and certain animals (e.g. ruminant). Here, we highlight recent case studies of the natural degraders and the mechanisms involved, providing new utilities in biotechnology. The sugars produced from such biotransformations can be used in metabolic engineering and synthetic biology for the complete biosynthesis of natural medicine. The unique opportunities in using lignocellulose directly to produce natural drug molecules with either using mushroom and/or ‘industrial workhorse’ organisms (Escherichia coli and Saccharomyces cerevisiae) will be discussed.


Holzforschung ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Lukas Emmerich ◽  
Maja Bleckmann ◽  
Sarah Strohbusch ◽  
Christian Brischke ◽  
Susanne Bollmus ◽  
...  

Abstract Chemical wood modification has been used to modify wood and improve its decay resistance. However, the mode of protective action is still not fully understood. Occasionally, outdoor products made from chemically modified timber (CMT) show internal decay while their outer shell remains intact. Hence, it was hypothesized that wood decay fungi may grow through CMT without losing their capability to degrade non-modified wood. This study aimed at developing a laboratory test set-up to investigate (1) whether decay fungi grow through CMT and (2) retain their ability to degrade non-modified wood. Acetylated and 1,3-dimethylol-4,5-dihydroxyethyleneurea (DMDHEU) treated wood were used in decay tests with modified ‘mantle specimens’ and untreated ‘core dowels’. It became evident that white rot (Trametes versicolor), brown rot (Coniophora puteana) and soft rot fungi can grow through CMT without losing their ability to degrade untreated wood. Consequently, full volume impregnation of wood with the modifying agent is required to achieve complete protection of wooden products. In decay tests with DMDHEU treated specimens, significant amounts of apparently non-fixated DMDHEU were translocated from modified mantle specimens to untreated wood cores. A diffusion-driven transport of nitrogen and DMDHEU seemed to be responsible for mass translocation during decay testing.


1985 ◽  
Vol 63 (2) ◽  
pp. 337-339 ◽  
Author(s):  
Elmer L. Schmidt

Influences of eight saturated aliphatic acids (C5–C10, C12, and C16) on basidiospores of four isolates of wood-decay fungi (Poria tenuis and Trametes hispida, white rot fungi, and two isolates of the brown rot fungus Gloeophyllum trabeum) were observed in vitro. Spore responses after 24 h on malt extract agar containing 10, 102 or 103 ppm of each acid included normal germination, delay of germ tube emergence, vacuolation and degeneration of spore cytoplasm, and prevention of germ tube development without spore destruction. Acids of chain length C5–C10 prevented spore germination and killed spores of all fungi at concentrations of 20–50 ppm in media, whereas other acids tested were less active. Spore germination assay of decay fungi may prove useful as a screening tool to compare potency of wood preservatives.


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.


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.


2004 ◽  
pp. 355-368 ◽  
Author(s):  
T. Mester ◽  
E. Varela ◽  
M. Tien

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