The coprini are a form group of mushrooms that grow mainly on compost and horse dung and that for over 100 years were thought to present one genus. Only in 2001 it was discovered by Redhead and coworkers by molecular analysis that the traditional genus comprises species of 4 different genera: Coprinus, Coprinopsis, Coprinellus and Parasola. Several species of the traditional genus, amongst the basidiomycete model species Coprinopsis cinerea (formerly Coprinus cinereus), found previously attention for mushroom development by the ease to grow and fruit the fungi in culture.
Surprisingly therefore, not even the pathway of fruiting body development for the model species c. cine re a was well presented in all different developmental stages in the literature. A task in this study was therefore to establish a picture catalogue of the events in the course of fruiting body development, up to fruiting body maturation and subsequent rapid autolysis of the mushrooms, a feature that is specific for many species of the coprini. Due to tills autolysis, mushroom of coprini have so far made little use of e g. for medicinal purposes. A literature compilation in medical and pharmaceutical compounds shows however that coprini have a potential for such applications.
c. cinerea mycelia cultures attract mites that graze on the mycelium of the fungus. Upon an unintended infection of a culture by mites of the species Tyrophagus puirescentiae, the chance was taken to observe the behavior of the two species with each other. The mites were found to consume, albeit at different rates, mycelium of monokaryons and dikaryons including asexual spores (oidia) in the aerial mycelia. Furthermore, the animals consume cap tissues of fruiting bodies together with basidiospores but they leave the stipes aside. Basidiospores are ingested but not digested. They are excreted in compact faecal pellets. Basidiospores can still germinate after passing the gut of the mites, since there are about 400 spores in a faecal pellet, mycelia of all mating types will arise and upon germination directly mate giving rise to dikaryous able to fruit. Dikaryon formation between germinated siblings promotes inbreeding in a fungus that naturally is an outbreeding organism. Thus, mites clearly affect the ftuigal life cycle. In turn, the fungus also influences the mites. Eggs are laid by the mites next to the faecal spore pellets. When the larvae hatch after about 5 days, the germinated mycelium will have obtained already a considerable colony size, presenting food for the young mites.
Fruiting body development in the laboratory is not restricted to c. cinerea. In this thesis, fruiting body development was also followed up in Coprinopsis clastophylla and a species related to Coprinellus curtus, initiated by the observation that these species form unusual shaped mushrooms. Sometimes tile structures are fully sterile, not forming basidiospores. The obtained fruiting body like structures are considered as anamorphs producing special mitotic cells (bulbils, lysomeres. or spherocytes) for vegetative reproduction. Molecular analysis of ITS sequences confirm that the strains described in the literature as anamorph Rhacophyllus iilacinus belongs to the genus Coprmopsis and the species c. clasiophylla (Coprinus clastophyllus). Other strains with unusual shaped mushrooms were assigned by ITS sequences to the genus Coprinelius to a species closely related to c. curt US. Morphologically, the mushrooms of tins unidentified species are not distinguishable from mushroom descriptions of Coprinopsis stereorea. Orton and Watling (1979) described c. stercorea to be heterothallic. Our isolate however is homothallic This difference in the breeding systems can explain contradictory reports on c. stercorea in earlier literature on occurrence of homothallism and heterothallism in the species. Another reason to study c. ciastophyila in Ulis thesis was because of reports on the fungus in the literature as growing on wood. Also other species of the coprini were said to grow on wood, but a systematic study so far was not available. Therefore, all available literature on coprini on wood was collected and analyzed. It was foiuid that about 30% of species in the new genera (Coprinus, Coprinopsis, Coprinellus, and Parasola) have been observed OI1 wood, suggesting that the ability of the fungi to grow on wood was more extended amongst these fungi than formerly thought. Attempts were undertaken with collections of coprini to grow the fungi on lignocellulosic material including wood (poplar, beech), ttlieat straw and oak and maple leave litter. Prior to the growth test, species identity was controlled by analysis of ITS sequences. It tt'as found that several isolates wrere assigned to wrong coprini species, and in one case even to a wrong genus indicating the difficulty of morphological identification of coprini. Several of the tested strains identified to the species Coprinus comatus, Coprinopsis strossmayeri, Coptine ỈỈUS curt US. Coprinellus micaceus. Coprinellus radians, Coprinellus xanthothrix, and 2 unidentified Coprinellus species, grow (Ml wood and straw, but degradation of lignocellulose by these species appears not to be considerable. Probably, the fungi rather glow on the storage material present in the parenchymatic cells of the wood and straw. On leave litter, growth occurred only in exceptional cases, suggesting that phenolic compounds in the fallen leaves inhibit fungal growth and/or that the leaves do not contain easily accessible nutrients. To further get insight into the ability of the species to degrade lignocellulose. phenoloxidase activities and in particular laccase activities of the strains were tested. At least on straw, most strains had visible enzymatic activities. Participation of Uiese enzymes in substrate degradation has to be studied further in the future.
Laccase activity had also been connected in the past to fruiting body development. Therefore, laccase activity and laccase gene expression was followed up during growth and development in c. cine re a. Activity of gene transcription and enzymatic activity was highest in the later stages of fruiting body development (primordia. karyogamy. meiosis and basidiospore formation, and in maturation and autolysis of the fruiting bodies). Laccases were found to be induced by addition of copper in the medium but induction levels were relatively low. The result suggests that in this fungus laccases have rather developmental functions, such as in pigment formation, than functions in substrate utilization. Copper addition had further surprising effects on fruiting body development of tile species. Fruiting was induced at the unusual temperature of 37°c together with nitrate reductase activity at a stage when the fungus actively increased the pH of the medium by ammonium production. Since nitrite reductase activity was not found, it is unlikely that ammonium secretion is due to combined actions of nitrate and nitrite reductases.
Surprisingly therefore, not even the pathway of fruiting body development for the model species c. cine re a was well presented in all different developmental stages in the literature. A task in this study was therefore to establish a picture catalogue of the events in the course of fruiting body development, up to fruiting body maturation and subsequent rapid autolysis of the mushrooms, a feature that is specific for many species of the coprini. Due to tills autolysis, mushroom of coprini have so far made little use of e g. for medicinal purposes. A literature compilation in medical and pharmaceutical compounds shows however that coprini have a potential for such applications.
c. cinerea mycelia cultures attract mites that graze on the mycelium of the fungus. Upon an unintended infection of a culture by mites of the species Tyrophagus puirescentiae, the chance was taken to observe the behavior of the two species with each other. The mites were found to consume, albeit at different rates, mycelium of monokaryons and dikaryons including asexual spores (oidia) in the aerial mycelia. Furthermore, the animals consume cap tissues of fruiting bodies together with basidiospores but they leave the stipes aside. Basidiospores are ingested but not digested. They are excreted in compact faecal pellets. Basidiospores can still germinate after passing the gut of the mites, since there are about 400 spores in a faecal pellet, mycelia of all mating types will arise and upon germination directly mate giving rise to dikaryous able to fruit. Dikaryon formation between germinated siblings promotes inbreeding in a fungus that naturally is an outbreeding organism. Thus, mites clearly affect the ftuigal life cycle. In turn, the fungus also influences the mites. Eggs are laid by the mites next to the faecal spore pellets. When the larvae hatch after about 5 days, the germinated mycelium will have obtained already a considerable colony size, presenting food for the young mites.
Fruiting body development in the laboratory is not restricted to c. cinerea. In this thesis, fruiting body development was also followed up in Coprinopsis clastophylla and a species related to Coprinellus curtus, initiated by the observation that these species form unusual shaped mushrooms. Sometimes tile structures are fully sterile, not forming basidiospores. The obtained fruiting body like structures are considered as anamorphs producing special mitotic cells (bulbils, lysomeres. or spherocytes) for vegetative reproduction. Molecular analysis of ITS sequences confirm that the strains described in the literature as anamorph Rhacophyllus iilacinus belongs to the genus Coprmopsis and the species c. clasiophylla (Coprinus clastophyllus). Other strains with unusual shaped mushrooms were assigned by ITS sequences to the genus Coprinelius to a species closely related to c. curt US. Morphologically, the mushrooms of tins unidentified species are not distinguishable from mushroom descriptions of Coprinopsis stereorea. Orton and Watling (1979) described c. stercorea to be heterothallic. Our isolate however is homothallic This difference in the breeding systems can explain contradictory reports on c. stercorea in earlier literature on occurrence of homothallism and heterothallism in the species. Another reason to study c. ciastophyila in Ulis thesis was because of reports on the fungus in the literature as growing on wood. Also other species of the coprini were said to grow on wood, but a systematic study so far was not available. Therefore, all available literature on coprini on wood was collected and analyzed. It was foiuid that about 30% of species in the new genera (Coprinus, Coprinopsis, Coprinellus, and Parasola) have been observed OI1 wood, suggesting that the ability of the fungi to grow on wood was more extended amongst these fungi than formerly thought. Attempts were undertaken with collections of coprini to grow the fungi on lignocellulosic material including wood (poplar, beech), ttlieat straw and oak and maple leave litter. Prior to the growth test, species identity was controlled by analysis of ITS sequences. It tt'as found that several isolates wrere assigned to wrong coprini species, and in one case even to a wrong genus indicating the difficulty of morphological identification of coprini. Several of the tested strains identified to the species Coprinus comatus, Coprinopsis strossmayeri, Coptine ỈỈUS curt US. Coprinellus micaceus. Coprinellus radians, Coprinellus xanthothrix, and 2 unidentified Coprinellus species, grow (Ml wood and straw, but degradation of lignocellulose by these species appears not to be considerable. Probably, the fungi rather glow on the storage material present in the parenchymatic cells of the wood and straw. On leave litter, growth occurred only in exceptional cases, suggesting that phenolic compounds in the fallen leaves inhibit fungal growth and/or that the leaves do not contain easily accessible nutrients. To further get insight into the ability of the species to degrade lignocellulose. phenoloxidase activities and in particular laccase activities of the strains were tested. At least on straw, most strains had visible enzymatic activities. Participation of Uiese enzymes in substrate degradation has to be studied further in the future.
Laccase activity had also been connected in the past to fruiting body development. Therefore, laccase activity and laccase gene expression was followed up during growth and development in c. cine re a. Activity of gene transcription and enzymatic activity was highest in the later stages of fruiting body development (primordia. karyogamy. meiosis and basidiospore formation, and in maturation and autolysis of the fruiting bodies). Laccases were found to be induced by addition of copper in the medium but induction levels were relatively low. The result suggests that in this fungus laccases have rather developmental functions, such as in pigment formation, than functions in substrate utilization. Copper addition had further surprising effects on fruiting body development of tile species. Fruiting was induced at the unusual temperature of 37°c together with nitrate reductase activity at a stage when the fungus actively increased the pH of the medium by ammonium production. Since nitrite reductase activity was not found, it is unlikely that ammonium secretion is due to combined actions of nitrate and nitrite reductases.
[EBOOK] Growth, fruiting body development and laccase production of selected coprini, By Dr. Gerhard Brau and Dr. Andrea Polle
Keyword: ebook, giáo trình, Growth, fruiting body development and laccase production of selected coprini, coprini, bọ hung, bọ cánh cứng, tăng trưởng và phát triển của bọ hung
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