50 resultados para Fungi imperfecti.
Resumo:
The development of biotechnology techniques in plant breeding and the new commercial applications have raised public and scientific concerns about the safety of genetically modified (GM) crops and trees. To find out the feasibility of these new technologies in the breeding of commercially important Finnish hardwood species and to estimate the ecological risks of the produced transgenic plants, the experiments of this study have been conducted as a part of a larger project focusing on the risk assessment of GM-trees. Transgenic Betula pendula and Populus trees were produced via Agrobacterium mediated transformation. Stilbene synthase (STS) gene from pine (Pinus sylvestris) and chitinase gene from sugar beet (Beta vulgaris) were transferred to (hybrid) aspen and birch, respectively, to improve disease resistance against fungal pathogens. To modify lignin biosynthesis, a 4-coumarate:coenzyme A ligase (4CL) gene fragment in antisense orientation was introduced into two birch clones. In in vitro test, one transgenic aspen line expressing pine STS gene showed increased resistance to decay fungus Phellinus tremulae. In the field, chitinase transgenic birch lines were more susceptible to leaf spot (Pyrenopeziza betulicola) than the non-transgenic control clone while the resistance against birch rust (Melampsoridium betulinum) was improved. No changes in the content or composition of lignin were detected in the 4CL antisense birch lines. In order to evaluate the ecological effects of the produced GM trees on non-target organisms, an in vitro mycorrhiza experiment with Paxillus involutus and a decomposition experiment in the field were performed. The expression of a transgenic chitinase did not disturb the establishment of mycorrhizal symbiosis between birch and P. involutus in vitro. 4CL antisense transformed birch lines showed retarded root growth but were able to form normal ectomycorrhizal associations with the mycorrhizal fungus in vitro. 4CL lines also showed normal litter decomposition. Unexpected growth reductions resulting from the gene transformation were observed in chitinase transgenic and 4CL antisense birch lines. These results indicate that genetic engineering can provide a tool in increasing disease resistance in Finnish tree species. More extensive data with several ectomycorrhizal species is needed to evaluate the consequences of transgene expression on beneficial plant-fungus symbioses. The potential pleiotropic effects of the transgene should also be taken into account when considering the safety of transgenic trees.
Resumo:
Basidiomycetous white-rot fungi are the only organisms that can efficiently decompose all the components of wood. Moreover, white-rot fungi possess the ability to mineralize recalcitrant lignin polymer with their extracellular, oxidative lignin-modifying enzymes (LMEs), i.e. laccase, lignin peroxidase (LiP), manganese peroxidase (MnP), and versatile peroxidase (VP). Within one white-rot fungal species LMEs are typically present as several isozymes encoded by multiple genes. This study focused on two effi cient lignin-degrading white-rot fungal species, Phlebia radiata and Dichomitus squalens. Molecular level knowledge of the LMEs of the Finnish isolate P. radiata FBCC43 (79, ATCC 64658) was complemented with cloning and characterization of a new laccase (Pr-lac2), two new LiP-encoding genes (Pr-lip1, Pr-lip4), and Pr-lip3 gene that has been previously described only at cDNAlevel. Also, two laccase-encoding genes (Ds-lac3, Ds-lac4) of D. squalens were cloned and characterized for the first time. Phylogenetic analysis revealed close evolutionary relationships between the P. radiata LiP isozymes. Distinct protein phylogeny for both P. radiata and D. squalens laccases suggested different physiological functions for the corresponding enzymes. Supplementation of P. radiata liquid culture medium with excess Cu2+ notably increased laccase activity and good fungal growth was achieved in complex medium rich with organic nitrogen. Wood is the natural substrate of lignin-degrading white-rot fungi, supporting production of enzymes and metabolites needed for fungal growth and the breakdown of lignocellulose. In this work, emphasis was on solid-state wood or wood-containing cultures that mimic the natural growth conditions of white-rot fungi. Transcript analyses showed that wood promoted expression of all the presently known LME-encoding genes of P. radiata and laccase-encoding genes of D. squalens. Expression of the studied individual LME-encoding genes of P. radiata and D. squalens was unequal in transcript quantities and apparently time-dependent, thus suggesting the importance of several distinct LMEs within one fungal species. In addition to LMEs, white-rot fungi secrete other compounds that are important in decomposition of wood and lignin. One of these compounds is oxalic acid, which is a common metabolite of wood-rotting fungi. Fungi produce also oxalic-acid degrading enzymes of which the most widespread is oxalate decarboxylase (ODC). However, the role of ODC in fungi is still ambiguous with propositions from regulation of intra and extracellular oxalic acid levels to a function in primary growth and concomitant production of ATP. In this study, intracellular ODC activity was detected in four white-rot fungal species, and D. squalens showed the highest ODC activity upon exposure to oxalic acid. Oxalic acid was the most common organic acid secreted by the ODC-positive white-rot fungi and the only organic acid detected in wood cultures. The ODC-encoding gene Ds-odc was cloned from two strains of D. squalens showing the first characterization of an odc-gene from a white-rot polypore species. Biochemical properties of the D. squalens ODC resembled those described for other basidiomycete ODCs. However, the translated amino acid sequence of Ds-odc has a novel N-terminal primary structure with a repetitive Ala-Ser-rich region of ca 60 amino acid residues in length. Expression of the Ds-odc transcripts suggested a constitutive metabolic role for the corresponding ODC enzyme. According to the results, it is proposed that ODC may have an essential implication for the growth and basic metabolism of wood-decaying fungi.
Resumo:
Puu, ruohokasvit ja näistä tehdyt tuotteet kuten mekaanisesta massasta valmistettu sanomalehtipaperi sisältävät ligniiniä, joka hajoaa yleensä hyvin hitaasti luonnossa. Valkolahosienet hajottavat ligniiniä tehokkaimmin, ja koska niiden tuottamat entsyymit hajottavat myös muita vaikeasti hajoavia yhdisteitä, voidaan valkolahosienten avulla mahdollisesti puhdistaa saastuneita maita. Tässä työssä haluttiin selvittää, säilyttävätkö valkolahosienet (Abortiporus biennis, Bjerkandera adusta, Dichomitus squalens, Phanerochaete chrysosporium, Phanerochaete sordida, Phlebia radiata, Pleurotus ostreatus, Trametes hirsuta ja Trametes versicolor) aktiivisuutensa ja kasvavatko ne maassa. Aktiivisuutta mitattiin seuraamalla sienten synteettisen ligniinin (14C-DHP) hajotuskykyä. T. versicolor (silkkivyökääpä) osoittautui tehokkaimmaksi ligniinin hajottajaksi ja sen pentakloorifenolin (PCP) hajotuskykyä tutkittiin erillisessä kokeessa. Entiset tai pitkään käytössä olleet saha-alueet ovat yhä saastuneet puun käsittelyaineista peräisin olevilla kloorifenoleilla. Biohajoavien muovien kehitystyö sekä kompostoinnin yleistyminen jätteiden käsittelymenetelmänä ovat luoneet tarpeen materiaalien biohajoavuuden määrittämiseen. Euroopan standardisoimisjärjestön (CEN) kontrolloidussa kompostitestissä biohajoavuus määritetään materiaalin hajoamisen aikana muodostuvan hiilidioksidin perusteella. Hiilidioksidin tuotto mitataan sekä näytettä sisältävästä kompostista että kompostista ilman näytettä, ja tällöin oletetaan, että kompostin orgaaninen aines molemmissa komposteissa (tausta) tuottaa yhtä paljon hiilidioksidia. Testin puutteeksi saattaa osoittautua kompostissa tai maassa esiintyvä "priming effect". Tällä tarkoitetaan materiaalin lisäämisen jälkeen esiintyvää epänormaalin suurita tai pientä hiilidioksidin muodostusta, minkä seurauksena testin tulosksena saatava biohajoavuus on virheellinen. Ligniinin hajotessa muodostuu enemmän humusta kuin hiilidioksidia, koska ligniini on humuksen tärkein lähtöaine. Näin ollen ligniiniä sisältävät paperituotteet saattavat testin mukaan vaikuttaa biologisesti hajoamattomilta. Valkolahosienet hajottivat 4-23% ligniinistä hiilidioksidiksi ja T. versicolor 29% PCP:sta. Kompostissa ligniini hajosi hiilidioksidiksi 58°C:ssa huomattavasti vähemmän (8%) kuin lämpötiloissa 35°C ja 50°C (23-24%). Kompostin todennäköisesti tärkeimpien ligniinin hajottajien, termofiilisten sienten, tyypillinen optimilämpötila on 45°C, eivätkä ne ole enää aktiivisia 58°C:ssa. Sekä maassa että kompostissa ligniini sitoutui kuitenkin suurimmaksi osaksi humukseen. Valkolahosienet hajottivat sekä humukseen sitoutunutta ligniiniä että PCP:ia, mutta kompostin sekapopulaatio ei tähän pystynyt, ja ligniiniä sitoutui humukseen yhä enemmän kompostoinnin aikana. T. versicolor hajotti PCP:ia tehokkaasti, eikä se tuottanut myrkyllisiä kloorianisoleja, joita jotkut valkolahosienet saattavat muodostaa kloorifenoleista. Priming effect ilmiötä tutkittiin eri ikäisissä ja kypsyydeltään erilaisissa komposteissa. Kompostit erosvat toisistaan myös hajoamattoman jätteen määrän ja mikrobipopulaation suhteen. Negatiivinen priming effect havaittiin kaikissa epästabiileissa komposteissa (ikä enintään 6 kk), ja sen lisäksi yhdessä näistä komposteista positiivinen priming effect kokeen lopussa. Stabiileissa komposteissa (ikä vähintään 6 kk) ilmiötä ei sen sijaan havaittu. Epästabiileissa komposteissa biohajoavuudelle saadut tulokset eivät siis ole luotettavia. Työn tulosten perusteella valkolahosienet, ja erityisesti T. versicolor, ovat lupaavia saastuneen maan puhdistukseen, joskin sienirihmaston mahdollisuudet säilyä aktiivisena maan alkuperäisen mikrobipopulaation kanssa täytyy vielä selvittää. Kompostin sekapopulaatio, joka ei sisällä valkolahosieniä, hajotti ligniiniä yllättävän tehokkaasti termofiilisille sienille sopivissa lämpötiloissa, vaikka ligniini sitoutuikin pääasiallisesti humukseen. Kompostin kypsyys osoittautui tärkeäksi tekijäksi kontrolloidun kompostitestin onnistumisen kannalta. Priming effect ilmiön välttämiseksi on varmistettava, että testissä käytetty komposti on riittävän kypsä. Kompostien mikrobipopulaation koostumusta kompostoinnin eri vaiheissa tulisi tarkemmin selvittää, koska stabiilien ja epästabiilien kompostien ero aiheutui todennäköisesti populaatioiden rakenteessa vallitsevista eroista. Näin myös priming effect ilmiön syyt voitaisiin selittää paremmin.
Resumo:
Despite much research on forest biodiversity in Fennoscandia, the exact mechanisms of species declines in dead-wood dependent fungi are still poorly understood. In particular, there is only limited information on why certain fungal species have responded negatively to habitat loss and fragmentation, while others have not. Understanding the mechanisms behind species declines would be essential for the design and development of ecologically effective and scientifically informed conservation measures, and management practices that would promote biodiversity in production forests. In this thesis I study the ecology of polypores and their responses to forest management, with a particular focus on why some species have declined more than others. The data considered in the thesis comprise altogether 98,318 dead-wood objects, with 43,085 observations of 174 fungal species. Out of these, 1,964 observations represent 58 red-listed species. The data were collected from 496 sites, including woodland key habitats, clear-cuts with retention trees, mature managed forests, and natural or natural-like forests in southern Finland and Russian Karelia. I show that the most relevant way of measuring resource availability can differ to a great extent between species seemingly sharing the same resources. It is thus critical to measure the availability of resources in a way that takes into account the ecological requirements of the species. The results show that connectivity at the local, landscape and regional scales is important especially for the highly specialized species, many of which are also red-listed. Habitat loss and fragmentation affect not only species diversity but also the relative abundances of the species and, consequently, species interactions and fungal successional pathways. Changes in species distributions and abundances are likely to affect the food chains in which wood-inhabiting fungi are involved, and thus the functioning of the whole forest ecosystem. The findings of my thesis highlight the importance of protecting well-connected, large and high-quality forest areas to maintain forest biodiversity. Small habitat patches distributed across the landscape are likely to contribute only marginally to protection of red-listed species, especially if habitat quality is not substantially higher than in ordinary managed forest, as is the case with woodland key habitats. Key habitats might supplement the forest protection network if they were delineated larger and if harvesting of individual trees was prohibited in them. Taking the landscape perspective into account in the design and development of conservation measures is critical while striving to halt the decline of forest biodiversity in an ecologically effective manner.
Resumo:
Ectomycorrhizal formation between the host tree, Pinus sylvestris and fungal symbiont, Suillus bovinus was investigated at the molecular level by isolating genes regulating the organization of the actin cytoskeleton in the fungal partner S. bovinus. An Agrobacterium tumefaciens mediated transformation (ATMT) system was developed for the ectomycorrhizal fungi in order to assign specific functions to the cloned molecules. The developed ATMT system was also used to transform a plant pathogenic fungus, Helminthosporium turcicum, to hygromycin B resistance. Small GTPases Cdc42 and Rac1, the regulators of actin cytoskeleton in eukaryotes were isolated from S. bovinus. Sbcdc42 and Sbrac1, are both expressed in vegetative and in the symbiotic hyphae of S. bovinus . Using IIF microscopy, Cdc42 and actin were co-localized at the tips of vegetative hyphae and were visualized in association with the plasma membrane in swollen cells typical to the symbiotic hyphae. These results suggest that the small GTPases Cdc42 may play a significant role in the polarized growth of S. bovinus hyphae and regulate fungal morphogenesis during ectomycorrhiza formation through reorganization of the actin cytoskeleton. The functional equality of Cdc42 was tested in yeast complementation experiments using a Saccharomyces cerevisiae temperature sensitive mutant, cdc42-1ts. The genomic clone of CDC42 was isolated from S. bovinus genomic DNA via specific primers for Cdc42. The analogous S. cerevisiae cdc42 mutations, dominant active G12V and dominant negative D118A, were generated in the Sbcdc42 gene by in-vitro mutagenesis. The ectomycorrhizal fungi, S. bovinus, P. involutus and H. cylindroporum were transformed using ATMT and phleomycin as a selectable marker. PCR screeing suggested that the T-DNA was inserted in all the three fungal genomes but the fate of integration could not be proved by Southern blot analysis. An alternative Agrobacterium strain, AGL-1 and selection marker, hygromycin was used to transform our model fungus S. bovinus. PCR and Southern analysis suggested an improved efficiency of transformation. All the transformed fungal colonies selected for hygromycin gave positives in PCR and the Southerns showed multiple or single copy T-DNA integrations into the S. bovinus genome. Using the same Agrobacterium strain and the selectable marker, a maize pathogen, H. turcicum was also subjected to ATMT. The H. turcicum transformation data suggested the single copy T-DNA integrations into the genome of the screened transformants that further confirms wider applicability of the ATMT. The plasmids carrying the wild-type (pHGCDC42) and the mutated Sbcdc42 alleles (pHGGV; pHGDA) under Agaricus bisporus gpd promoter were constructed in an A. tumefaciens vector. ATMT was used to transform S. bovinus with the plasmids carrying the wild-type and mutated Sbcdc42 alleles. The isolation of Sbcdc42 and Sbrac1 genes and some other functionally related genes from ectomycorrhizal fungus, S. bovinus will form the basis of future work to resolve the signalling pathway leading to ectomycorrhizal symbiosis. The development of ATMT system will be a valuable tool in analysing the exact function of signalling pathway components in ectomycorrhizal symbiosis or in plant pathogenic interactions. The transformation frequency and broad applicability along with the simplicity of T-DNA integration make Agrobacterium a valuable, new and a powerfull tool for targeted and insertional mutagenesis in these plant associated fungi. The developed ATMT systems should therefore make it possible to generate large number of transformants with tagged genes which could then be screened for their specific roles in symbiosis and pathogenecity, respectively.
Resumo:
Fungi have a fundamental role in carbon and nutrient transformations in the acids soils of boreal regions, such as peatlands, where high amounts of carbon (C) and nutrients are stored in peat, the pH is relatively low and the nutrient uptake of trees is highly dependent on mycorrhizae. In this thesis, the aim was to examine nitrogen (N) transformations and the availability of dissolved N compounds in forestry-drained peatlands, to compare the fungal community biomass and structure at various peat N levels, to investigate the growth of ectomycorrhizal fungi with variable P and K availability and to assess how the ectomycorrhizal fungi (ECM) affect N transformations. Both field and laboratory experiments were carried out. The peat N concentration did not affect the soil fungal community structure within a site. Phosphorus (P) and potassium (K) deficiency of the trees as well as the degree of decomposition and dissolved organic nitrogen (DON) concentration of the peat were shown to affect the fungal community structure and biomass of ECMs, highlighting the complexity of the below ground system on drained peatlands. The biomass of extrametrical mycorrhizal mycelia (EMM) was enhanced by P and/or K deficiency of the trees, and ECM biomass in the roots was increased by P deficiency. Thus, PK deficiency in drained peatlands may increase the allocation of C by the tree to ECMs. It was also observed that fungi can alter N mineralization processes in the rhizosphere but variously depending on fungal species and fertility level of peat. Gross N mineralization did not vary but the net N mineralization rate significantly increased along the N gradient in both field and laboratory experiments. Gross N immobilization also significantly increased when the peat N concentration increased. Nitrification was hardly detectable in either field or laboratory experiments. During the growing season, dissolved inorganic N (DIN) fluctuated much more than the relatively stable DON. Special methodological challenges associated with sampling and analysis in microbial studies on peatlands are discussed.
Resumo:
Filamentous fungi of the subphylum Pezizomycotina are well known as protein and secondary metabolite producers. Various industries take advantage of these capabilities. However, the molecular biology of yeasts, i.e. Saccharomycotina and especially that of Saccharomyces cerevisiae, the baker's yeast, is much better known. In an effort to explain fungal phenotypes through their genotypes we have compared protein coding gene contents of Pezizomycotina and Saccharomycotina. Only biomass degradation and secondary metabolism related protein families seem to have expanded recently in Pezizomycotina. Of the protein families clearly diverged between Pezizomycotina and Saccharomycotina, those related to mitochondrial functions emerge as the most prominent. However, the primary metabolism as described in S. cerevisiae is largely conserved in all fungi. Apart from the known secondary metabolism, Pezizomycotina have pathways that could link secondary metabolism to primary metabolism and a wealth of undescribed enzymes. Previous studies of individual Pezizomycotina genomes have shown that regardless of the difference in production efficiency and diversity of secreted proteins, the content of the known secretion machinery genes in Pezizomycotina and Saccharomycotina appears very similar. Genome wide analysis of gene products is therefore needed to better understand the efficient secretion of Pezizomycotina. We have developed methods applicable to transcriptome analysis of non-sequenced organisms. TRAC (Transcriptional profiling with the aid of affinity capture) has been previously developed at VTT for fast, focused transcription analysis. We introduce a version of TRAC that allows more powerful signal amplification and multiplexing. We also present computational optimisations of transcriptome analysis of non-sequenced organism and TRAC analysis in general. Trichoderma reesei is one of the most commonly used Pezizomycotina in the protein production industry. In order to understand its secretion system better and find clues for improvement of its industrial performance, we have analysed its transcriptomic response to protein secretion stress conditions. In comparison to S. cerevisiae, the response of T. reesei appears different, but still impacts on the same cellular functions. We also discovered in T. reesei interesting similarities to mammalian protein secretion stress response. Together these findings highlight targets for more detailed studies.
Resumo:
The Scots pine bark beetle, Tomicus piniperda is a secondary colonizer of pine and other conifers. It is a native species from Europe and Asia that was recently introduced in North America. Although it is necessary to understand this insect's interactions with other organisms, few studies have focussed on its fungal associates. This study focused on the effect of latitude in the occurrence of fungi associated with T. piniperda. T. piniperda were collected from Pinus sylvestris in Northern (Rovaniemi) and Southern (Hyytiala) Finland. Both endo- and epi- mycota were isolated. The fungi were identified using a combination of morphological features and molecular data. The results revealed a great diversity of fungi species associated with T. piniperda, with a total of 3073 isolates representing 23 species. The most frequently isolated fungi in the bark beetles from Northern Finland were Beauvaria bassiana, Kuraishia sp. and Penicillium sp. whereas P. brevicompactum and Mortierella sp. were mostly observed in the South. Ophiostoma canum and O. minus were also observed. The number of isolates per insect in the north was 2.83 epi- and 2.38 for endo-mycota fungus. In the south, the number of isolates per insect was 4.1 for epi- and 3.5 for endo-mycota. Statistical analysis indicated that there was significant differences in fungal populations associated with the beetles in Southern and Northern Finland. There was however no significant difference between the epi- and endo-mycota fungal populations. The highest richness and diversity of the fungal species was observed in the South. However, the overall fungal diversity index analysis revealed that the mycobiota was undersampled.
Resumo:
This study is based on the multidiciplinary approach of using natural colorants as textile dyes. The author was interested in both the historical and traditional aspects of natural dyeing as well as the modern industrial applications of the pure natural compounds. In the study, the anthraquinone compounds were isolated as aglycones from the ectomycorrhizal fungus Dermocybe sanguinea. The endogenous beta-glucosidase of the fungus was used to catalyse the hydrolysis of the O-glycosyl linkage in emodin- and dermocybin-1-beta-D-glucopyranosides. The method, in which 10.45 kg of fresh fungi was starting material, yielded two fractions: 56.0 g of Fraction 1 (94% of the total amount of pigment,) consisting almost exclusively of the main pigments emodin and dermocybin, and 3.3 g of Fraction 2 (6%) consisting mainly of the anthraquinone carboxylic acids. The anthraquinone compounds in Fractions 1 and 2 were separated by one- and two-dimensional thin-layer-chromatography (TLC) using silica plates. 1D TLC showed that neither an acidic nor a basic solvent system alone separated completely all the anthraquinones isolated from D. sanguinea, in spite of the variation of the rations of the solvent components in the systems. Thus, a new 2D TLC technique was developed, applying n-pentanol-pyridine-methanol (6:4:3, v/v/v) and toluene-ethyl acetate-ethanol-formic acid (10:8:1:2, v/v/v/v) as eluents. Fifteen different anthraquinone derivatives were completely separated from one another. Emodin, physcion, endocrocin, dermolutein, dermorubin, 5-chlorodermorubin, emodin-1-beta-D-glucopyranoside, dermocybin-1-beta-D-glucopyranoside and dermocybin, and five new compounds, not earlier identified in D. sanguinea, 7-chloroemodin, 5,7-dichloroemodin, 5,7-dichloroendocrocin, 4-hydroxyaustrocorticone and austrocorticone, were separated and identified on the basis of their Rf-values, UV/Vis spectra and mass spectra. One substance remained unidentified, because of its very low concentration. The anthraquinones in Fractions 1 and 2 were preparatively separeted by liquid-liquid partition, with isopropylmethyl ketone and aqueous phosphate buffer as the solvent system. Advantage was taken of the principle of stepwise pH-gradient elution. The multiple liquid-liquid partition (MLLP) offered an excellent method for the preparative separation of compounds, which contain acidic groups such as the phenolic OH and COOH groups. Due to their strong aggregation properties, these compounds are, without derivatization, very difficult to separate on a preparative scale by chromatographic methods. By the MLLP method remarkable separations were achieved for the components in each mixture. Emodin and dermocybin were both obtained from Fraction 1 in a purity of at least 99%. Pure emodin and dermocybin were applied as mordant dyes to wool and polyamide and as disperse dyes to polyester and polyamide, using the high temperature (HT) technique. A mixture of dermorubin and 5-chlorodermorubin was applied as an acid dye to wool. In these experiments, synthetic dyes were used as references. Experiments were also performed using water extract of the air-dried fungi as dye liquor for wool and silk. The main colouring compounds in the crude water extract were emodin and dermocybin, which indicated that the O-glycosyl linkages in emodin- and dermocybin-1-beta-D-glucopyranosides were broken by the beta-glucosidase enzyme. Apparently, the hydrolysis occurred during the drying of the fungi and during the soaking of the dried fruit bodies overnight when preparing the dyebath. The colour of each dyed material was investigated in terms of the CIELAB L*, a* and b* values, and the colour fastness to light, washing and rubbing was tested according to the ISO standards. In the mordant dyeing experiments, emodin dyed wool and polyamide yellow and red, depending on the pH of the dyebath. Dermocybin gave purple and violet colours. The colour fastness of the mordant-dyed fabrics varied from good to moderate. The fastness properties of the natural anthraquinone carboxylic acids on wool were good, indicating the strength of the ionic bonds between the COO- groups of the dyes and the NH3+ groups of the fibres. In the disperse dyeing experiments, emodin dyed polyester bright yellow and dermocybin bright reddish-orange, and the fabrics showed excellent colour fastness. In contrast, emodin and dermocybin successfully dyed polyamide brownish-orange and wine-red, respectively, but with only moderate fastness. In industrial dyeing processes, natural anthraquinone aglycone mixtures dyed wool and silk well even at low concentrations of mordants, i.e. with 10% of the weight of the fibre (owf) of KAl(SO4)2 and 1 or 0.5% owf of other mordants. This study showed that purified natural anthraquinone compounds can produce bright hues with good colour-fastness properties in different textile materials. Natural anthraquinones have a significant potential for new dyeing techniques and will provide useful alternatives to synthetic dyes.