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Truffles are ascomycete hypogeous fungi belonging to the Tuberaceae family of the Pezizales order that grow in ectomycorrhizal symbiosis with tree roots, and they are known for their peculiar aromas and flavors. The axenic culture of truffle mycelium is problematic because it is not possible in many cases, and the growth rate is meager when it is possible. This limitation has prompted searching and characterizing new strains that can be handled in laboratory conditions for basic and applied studies. In this work, a new strain of Tuber borchii (strain SP1) was isolated and cultured, and its transcriptome was analyzed under different in vitro culture conditions. The results showed that the highest growth of T. borchii SP1 was obtained using maltose-enriched cultures made with soft-agar and in static submerged cultures made at 22 °C. We analyzed the transcriptome of this strain cultured in different media to establish a framework for future comparative studies, paying particular attention to the central metabolic pathways, principal secondary metabolite gene clusters, and the genes involved in producing volatile aromatic compounds (VOCs). The results showed a transcription signal for around 80% of the annotated genes. In contrast, most of the transcription effort was concentrated on a limited number of genes (20% of genes account for 80% of the transcription), and the transcription profile of the central metabolism genes was similar in the different conditions analyzed. The gene expression profile suggests that T. borchii uses fermentative rather than respiratory metabolism in these cultures, even in aerobic conditions. Finally, there was a reduced expression of genes belonging to secondary metabolite clusters, whereas there was a significative transcription of those involved in producing volatile aromatic compounds.

The article provides growth, cultural and morphological characteristics of the vegetative mycelium on agar nutrient medium under the influence of laser irradiation for three strains of Laetiporus sulphureus from the Collection of basidiomycete cultures of the Department of Botany and Ecology of Vasyl' Stus Donetsk National University. The study was performed on potatoglucose agar (PGA) at a temperature of 26 ± 1 °C. It has been found that cultural and morphological characteristics of the colonies and the radial rate of their growth depend on the duration of irradiation (5 and 10 s) and the wavelength of light – green (532 nm), blue (405 nm) and red light (635 nm). For all studied strains of L. sulphureus, the most effective irradiation is that with green light (irradiation energy 51.1 mJ/cm2) lasting 10 s. Under the influence of this regime, the rate of radial mycelium growth increased from 23.4% to 66.7%, respectively, and the inoculum and the central zone of the surrounding colony formed a denser and higher mycelium of a pale sandy color. In general, the cultural and morphological features of the mycelial colonies of L. sulphureus strains under different conditions were somewhat different, but they were typical for this species.

The article provides cultural and morphological characteristics of vegetative mycelium on agar nutrient media of eight species (18 strains) of the genus Pholiota from the IBK Mushroom Culture Collection of the M.G. Kholodny Institute of Botany, National Academy of Sciences of Ukraine. The strains were cultivated on two different media, malt extract agar (MEA) and glucose-peptone-yeast agar (GPYA), at pH 6.0 and at the temperature 26±1 ºC. It has been shown that cultural characteristics of the colony morphology and the rate of radial growth depend on nutrient media composition and biological properties of the strains. Most strains formed white colonies, later becoming light yellow or from orange to dark brown. Some of the species were able to form strands and allocate exudates. A slow rate of radial growth (up 0.52±0.08 to 2.24±0.18 mm/day) for all strains of the studied Pholiota species was noticed. The highest rate of radial growth for most of the studied strains was observed on glucose-peptone-yeast agar.

Aim. To determine the value of the antioxidant activity of the biomass and culture fluid extracts of strains of seven species of Pholiota genus: P. adiposa, P. alnicola, P. aurivella, P. limonella, P. nameko, P. squarrosa, P. subochracea, which stored in the Mushroom Culture Collection (IBK) of the M. G. Kholodny Institute of Botany of the National Academy of Sciences of Ukraine.Materials and methods. The antioxidant properties of the biomass and culture fluid extracts of strains of Pholiota genus were determined by the method of Elfahri et al. using DPPH (1,1-diphenyl-2-picrylhydrazyl). Mycelia of the strains studied were grown by the surface method on a liquid glucose-pepton-yeast medium. The culture fluid was separated from the mycelial biomass by filtration through a capron filter. The absorption of methanol extracts of the culture fluid and the biomass of the strains studied was measured at 517 nm on a SF 46 LOMO spectrophotometer.Results and discussion. Comparing the data obtained we can conclude that the antioxidant effect is significantly higher in the case of methanol biomass extracts – the indicators ranged from 65.98 ± 0.98 % (P. nameko) to 83.6 ± 1.4 % (P. alnicola). As for the culture fluid extracts, the maximum values were recorded in the case of P. limonella (38.3 ± 1.14 %), and the minimum values were observed for P. subochracea (7.37 ± 0.46 %).Conclusions. For the first time, the value and limits of variation in the antioxidant activity of the biomass (65-83 %) and culture fluid extracts (7.4-38 %) have been determined for strains of medicinal fungal species P. adiposa, P. alnicola, P. aurivella, P. limonella, P. nameko, P. squarrosa, P. subochracea., Мета. Визначити величину антиоксидантної активності екстрактів біомаси та культуральної рідини штамів семи видів роду Pholiota: P. adiposa, P. alnicola, P. aurivella, P. limonella, P. nameko, P. squarrosa, P. subochracea, що їх зберігають у Колекції культур шапинкових грибів (IBK) Інституту ботаніки ім. М. Г. Холодного НАН України.Матеріали та методи. Антиоксидантні властивості екстрактів культуральної рідини та міцелію штамів видів роду Pholiota визначали методом Elfahri et al. з використанням DPPH (1,1-дифеніл-2-пікрилгідразилу). Міцелій досліджених штамів вирощували поверхневим методом на рідкому глюкозо-пептон-дріжджовому середовищі. Культуральну рідину відокремлювали від міцеліальної біомаси фільтруванням через капроновий фільтр. Поглинання метанольних екстрактів культуральної рідини та біомаси досліджених штамів вимірювали за 517 нм на спектрофотометрі SF 46 LOMO.Результати та їх обговорення. Порівнюючи отримані дані, можемо зробити висновок про значно вищу ефективність антиоксидантної дії у випадку метанольних екстрактів біомаси – показники варіювали від 65,98 ± 0,98 % (P. nameko) до 83,6 ± 1,4 % (P. alnicola). Щодо екстрактів культуральної рідини, то максимальні значення було зафіксовано у випадку P. limonella (38,3 ± 1,14 %), а мінімальні – P. subochracea (7,37 ± 0,46 %).Висновки. Уперше визначено величину та межі варіювання антиоксидантної активності екстрактів біомаси (65 – 83 %) та культуральної рідини (7,4 – 38 %) штамів лікарських видів грибів P. adiposa, P. alnicola, P. aurivella, P. limonella, P. nameko, P. squarrosa, P. subochracea.

Lithium salts are used in mood disorders, since this chemical element acts on the central nervous system. To increase the bioavailability of this metal, strategies are studied, such as bioaccumulation in basidiomycetes. Thus, the goal of project was to carry out a bibliographic review on the capacity of in vitro lithium bioaccumulation by basidiomycetes. Scientific articles on biocumulation, lithium and basidiomycetes published in the 1980s to 2020s were researched. An alternative for the treatment of bipolar mood disorder is lithium carbonate, but its therapeutic range is narrow, which can lead to drug intoxication. In vitro lithium bioaccumulation in basidiomycetes can help to reduce side effects and improve the bioavailability of lithium. Studies on lithium bioaccumulation in basidiomycetes are scarce, and most of them use LiCl as a source of lithium, probably due to its high solubility. The mycelial culture of fungi in liquid medium has been the best option for the production of lithium enriched biomass. Among the analyzed studies, Pleurotus ostreatus is the most studied species in lithium bioaccumulation, both in the form of basidiocarp and in the mycelial form. Other species such as Agaricus subrufescens, Ganoderma lucidum, Lentinus crinitus, Pleurotus eryngii have also been evaluated. Bioaccumulated mycelial biomass with lithium can be considered a supplementation option for treatment against bipolar mood disorders, or as a prevention to suicide and even Alzheimer's, and further studies are needed. Las sales de litio se utilizan en los trastornos del estado de ánimo, ya que este elemento químico actúa sobre el sistema nervioso central. Para aumentar la biodisponibilidad de este metal se estudian estrategias, como la bioacumulación en basidiomicetos. Así, el objetivo de este trabajo fue realizar una revisión bibliográfica sobre la capacidad de bioacumulación de litio in vitro por basidiomicetos. Se investigaron artículos científicos sobre bioacumulación, litio y basidiomicetos publicados en los años 1980 a 2020. Una alternativa para el tratamiento del trastorno bipolar del estado de ánimo es el carbonato de litio, pero su rango terapéutico es estrecho, lo que puede provocar intoxicación por fármacos. La bioacumulación de litio in vitro en basidiomicetos puede ayudar a reducir los efectos secundarios y mejorar la biodisponibilidad del litio. Los estudios sobre la bioacumulación de litio en basidiomicetos son escasos y la mayoría utiliza LiCl como fuente de litio, probablemente debido a su alta solubilidad. El cultivo micelial de hongos en medio líquido ha sido la mejor opción para la producción de biomasa enriquecida con litio. Entre los estudios analizados, Pleurotus ostreatus es la especie más estudiada en bioacumulación de litio, tanto en forma de basidiocarpo como en forma micelial. También se han evaluado otras especies como Agaricus subrufescens, Ganoderma lucidum, Lentinus crinitus, Pleurotus eryngii. La biomasa micelial bioacumulada con litio puede considerarse una opción complementaria para el tratamiento contra los trastornos bipolares del estado de ánimo, o como preventivo del suicidio e incluso del Alzheimer, siendo necesario realizar más estudios. Os sais de lítio são usados no transtorno de humor, uma vez que este elemento químico atua no sistema nervoso central. Para aumentar a biodisponibilidade deste metal, estratégias são estudadas, como a bioacumulação em basidiomicetos. Desta forma, o objetivo deste trabalho foi realizar uma revisão bibliográfica sobre a capacidade de bioacumulação de lítio in vitro por basidiomicetos. Artigos científicos sobre biocumulação, lítio e basidiomicetos publicados nos anos de 1980 a 2020 foram pesquisados. Uma alternativa para o tratamento do transtorno de humor bipolar é o carbonato de lítio, porém sua faixa terapêutica é estreita, o que pode levar a intoxicação medicamentosa. A bioacumulação de lítio in vitro em basidiomicetos pode ajudar na redução dos efeitos colaterais e melhorar a biodisponibilidade do lítio. São escassos os estudos sobre bioacumulação de lítio em basidiomicetos, e a maioria utiliza LiCl como fonte de lítio, provavelmente pela sua alta solubilidade. O cultivo micelial dos fungos em meio líquido têm sido a melhor opção para a produção de biomassa enriquecida com lítio. Dentre os estudos analisados, Pleurotus ostreatus é a espécie mais estudada na bioacumulação de lítio, tanto na forma de basidiocarpo quanto na forma micelial. Outras espécies como Agaricus subrufescens, Ganoderma lucidum, Lentinus crinitus, Pleurotus eryngii também já foram avaliadas. A biomassa micelial bioacumulada com lítio pode ser considerada uma opção de suplementação ao tratamento contra os distúrbios de humor bipolar, ou um preventivo ao suicídio e até mesmo ao Alzheimer, existindo a necessidade de novos estudos.

The aim of the study was to investigate the effect of laser irradiation of mycelium on the amount of biomass and synthesis of P. ostreatus polysaccharides.Materials and methods. For the study, 6 strains of P. ostreatus from the Collection of cultures of basidiomycetes of the Department of Botany and Ecology of Vasyl Stus DonNU were used. A device consisting of LED lasers was used for laser irradiation of vegetative mycelium: BRP – 3010–5, with red spectrum radiation with a wavelength of 635 nm; BBP – 3010–5 with blue spectrum radiation with a wavelength of 405 nm and BGP – 3010–5 with green spectrum radiation with a wavelength of 532 nm. The level of biomass accumulation was determined by weight. The polysaccharide content was determined by the phenol-sulfur method.Results. The most effective was green light irradiation with a wavelength of 532 nm. For strain P-192 – the amount of biomass increased by 71.4 %. For strains P-191 and P-155 biomass increased by 60 % and 53.5 %. For strains P-108, P-154 and P-6v, the amount of biomass increased from 33.3 to 50 %. For strain P-192, the amount of mycelial endopolysaccharides increased by 42.0 %. For strains P-191 and P-6v, the amount of endopolysaccharides increased by 39.3 % and 38.7 %. For strains P-108, P-155 and P-154 the amount of mycelium endopolysaccharides increased from 30.7 % to 35.8. For strain P-192 the content of exopolysaccharides increased by 30.5 %. For strains P-154 and P-191, the amount of exopolysaccharides increased by 28.1 % and 27.8 %. For strains P-108, P-155 and P-6v the content of exopolysaccharides increased from 24.6 % to 25.8 %.Conclusions. The most effective mode of photoactivation of P. ostreatus mycelium for obtaining target products was determined. In particular, the best response was observed in response to green light with a wavelength of 532 nm for strain P-192 – the amount of biomass increased by 71.4 %, the amount of mycelium endopolysaccharides increased by 42.0 %, and the content of exopolysaccharides increased by 30.5 %, Целью работы было исследование влияния лазерного облучения мицелия на количество биомассы и синтез полисахаридов P. ostreatus.Материалы и методы. Для исследования были использованы 6 штаммов гриба P. ostreatus с Коллекции культур базидиевих грибов кафедры ботаники и экологии ДонНУ имени Василия Стуса. Для лазерного облучения вегетативного мицелия использовали устройство, которое состоит из LED лазеров: BRP-3010-5, с излучением красного спектра с длиной волны 635нм; BBP-3010-5 с излучением синего спектра с длиной волны 405 нм и BGP-3010-5 с излучением зеленого спектра с длиной волны 532 нм. Уровень накопления биомассы определяли весовым методом. Содержание полисахаридов определяли фенол-серным методом.Результаты. Самым эффективным было облучения зеленым светом длиной волны 532 нм. Для штамма Р-192 – количество биомассы выросло на 71,4 %. Для штаммов Р-191 и Р-155 биомасса выросла на 60 % и на 53,5 %. Для штаммов Р-108, Р-154 и Р-6v показатель количества биомассы увеличивался от 33,3 до 50 %. Для штамма P-192 количество ендополисахаридив мицелия выросло на 42,0 %. Для штаммов Р-191 и Р-6v показатель количества ендополисахаридив увеличился на 39,3 % и на 38,7 %. Для штаммов Р-108, Р-155 и Р-154 количество ендополисахаридив мицелия выросло от 30,7 % до 35,8. Для штамма P-192 содержание экзополисахаридов выросло на 30,5 %. Для штаммов Р-154 и Р-191 показатель количества экзополисахаридов увеличился на 28,1 % и на 27,8 %. Для штаммов Р-108, Р-155 и Р-6v содержание экзополисахаридов увеличилось с 24,6 % до 25,8 %.Выводы. Определен наиболее эффективный режим фотоактивации мицелия P. ostreatus для получения целевых продуктов. В частности, лучшая реакция наблюдалась в ответ на действие зеленого света длиной волны 532 нм для штамма Р-192 – количество биомассы выросло на 71,4 %, количество ендополисахаридив мицелия выросло на 42,0 %, а содержание экзополисахаридов увеличилося на 30,5 %, Метою роботи було дослідження впливу лазерного опромінення міцелію на кількість біомаси та синтез полісахаридів P. ostreatus.Матеріали і методи. Для дослідження були використані 6 штамів гриба P. ostreatus із Колекції культур базидієвих грибів кафедри ботаніки та екології ДонНУ імені Василя Стуса. Для лазерного опромінення вегетативного міцелію використовували пристрій, який складається з LED лазерів: BRP–3010–5, з випромінюванням червоного спектра з довжиною хвилі 635нм; BBP–3010–5 з випромінюванням синього спектра з довжиною хвилі 405 нм та BGP–3010–5 з випромінюванням зеленого спектра з довжиною хвилі 532 нм. Рівень накопичення біомаси визначали ваговим методом. Вміст полісахаридів визначали фенол-сірчаним методом.Результати. Найефективнішим було опромінення зеленим світлом довжиною хвилі 532 нм. Для штаму Р-192 – кількість біомаси зросла на 71,4 %. Для штамів Р-191 та Р-155 біомаса зросла на 60 % та на 53,5 %. Для штамів Р-108, Р-154 та Р-6v показник кількості біомаси зростав від 33,3 до 50 %. Для штаму P-192 кількість ендополісахаридів міцелію зросла на 42,0 %. Для штамів Р-191 та Р-6v показник кількості ендополісахаридів збільшився на 39,3 % та на 38,7 %. Для штамів Р-108, Р-155 та Р-154 кількість ендополісахаридів міцелію зростала від 30,7 % до 35,8. Для штаму P-192 вміст екзополісахаридів зріс на 30,5 %. Для штамів Р-154 та Р-191 показник кількості екзополісахаридів збільшився на 28,1 % та на 27,8 %. Для штамів Р-108, Р-155 та Р-6v вміст екзополісахаридів збільшився від 24,6 % до 25,8 %.Висновки. Визначено найбільш ефективний режим фотоактивації міцелію P. ostreatus для отримання цільових продуктів. Зокрема, найкраща реакція спостерігалась у відповідь на дію зеленого світла довжиною хвилі 532 нм для штаму Р-192 – кількість біомаси зросла на 71,4 %, кількість ендополісахаридів міцелію зросла на 42,0 %, а вміст екзополісахаридів збільшився на 30,5 %

The aim of the studywas to investigate the effect of laser irradiation of mycelium on the amount of biomass and synthesis of P. ostreatus polysaccharides. Materials and methods.For the study, 6 strains of P. ostreatus from the Collection of cultures of basidiomycetes of the Department of Botany and Ecology of Vasyl Stus DonNU were used. A device consisting of LED lasers was used for laser irradiation of vegetative mycelium: BRP – 3010–5, with red spectrum radiation with a wavelength of 635 nm; BBP – 3010–5 with blue spectrum radiation with a wavelength of 405 nm and BGP – 3010–5 with green spectrum radiation with a wavelength of 532 nm. The level of biomass accumulation was determined by weight. The polysaccharide content was determined by the phenol-sulfur method. Results.The most effective was green light irradiation with a wavelength of 532 nm. For strain P-192 – the amount of biomass increased by 71.4 %. For strains P-191 and P-155 biomass increased by 60 % and 53.5 %. For strains P-108, P-154 and P-6v, the amount of biomass increased from 33.3 to 50 %. For strain P-192, the amount of mycelial endopolysaccharides increased by 42.0 %. For strains P-191 and P-6v, the amount of endopolysaccharides increased by 39.3 % and 38.7 %. For strains P-108, P-155 and P-154 the amount of mycelium endopolysaccharides increased from 30.7 % to 35.8. For strain P-192 the content of exopolysaccharides increased by 30.5 %. For strains P-154 and P-191, the amount of exopolysaccharides increased by 28.1 % and 27.8 %. For strains P-108, P-155 and P-6v the content of exopolysaccharides increased from 24.6 % to 25.8 %. Conclusions.The most effective mode of photoactivation of P. ostreatus mycelium for obtaining target products was determined. In particular, the best response was observed in response to green light with a wavelength of 532 nm for strain P-192 – the amount of biomass increased by 71.4 %, the amount of mycelium endopolysaccharides increased by 42.0 %, and the content of exopolysaccharides increased by 30.5 %

Saprobic fungi, such as Aspergillus niger, grow as colonies consisting of a network of branching and fusing hyphae that are often considered to be relatively uniform entities in which nutrients can freely move through the hyphae. In nature, different parts of a colony are often exposed to different nutrients. We have investigated, using a multi-omics approach, adaptation of A. niger colonies to spatially separated and compositionally different plant biomass substrates. This demonstrated a high level of intra-colony differentiation, which closely matched the locally available substrate. The part of the colony exposed to pectin-rich sugar beet pulp and to xylan-rich wheat bran showed high pectinolytic and high xylanolytic transcript and protein levels, respectively. This study therefore exemplifies the high ability of fungal colonies to differentiate and adapt to local conditions, ensuring efficient use of the available nutrients, rather than maintaining a uniform physiology throughout the colony. This article is protected by copyright. All rights reserved.

Aspergillus niger forms aerial hyphae and conidiophores after a period of vegetative growth. The hyphae within the mycelium of A. niger are divided by septa. The central pore in these septa allows for cytoplasmic streaming. Here, we studied inter- and intra-compartmental streaming of the reporter protein GFP in A. niger. Expression of the gene encoding nuclear targeted GFP from the gpdA or glaA promoter resulted in strong fluorescence of nuclei within the vegetative hyphae and weak fluorescence in nuclei within the aerial structures. These data and nuclear run on experiments showed that gpdA and glaA are higher expressed in the vegetative mycelium when compared to aerial hyphae, conidiophores and conidia. Notably, gpdA or glaA driven expression of the gene encoding cytosolic GFP resulted in strongly fluorescent vegetative hyphae and aerial structures. Apparently, GFP streams from vegetative hyphae into aerial structures. This was confirmed by monitoring fluorescence of photo-activatable GFP (PA-GFP). In contrast, PA-GFP did not stream from aerial structures to vegetative hyphae. Streaming of PA-GFP within vegetative hyphae or within aerial structures of A. niger occurred at a rate of 10-15 μm s-1. Taken together, these results not only show that GFP streams from the vegetative mycelium to aerial structures but it also indicates that its encoding RNA is not streaming. Absence of RNA streaming would explain why distinct RNA profiles were found in aerial structures and the vegetative mycelium by nuclear run on analysis and micro-array analysis. © CBS-KNAW Fungal Biodiversity Centre, P.O. Box 85167, 3508 AD Utrecht, The Netherlands.

The genus Aspergillus represents a diverse group of fungi that are among the most abundant fungi in the world. Germination of a spore can lead to a vegetative mycelium that colonizes a substrate. The hyphae within the mycelium are highly heterogeneous with respect to gene expression, growth, and secretion. Aspergilli can reproduce both asexually and sexually. To this end, conidiophores and ascocarps are produced that form conidia and ascospores, respectively. This review describes the molecular mechanisms underlying growth and development of Aspergillus. © CBS-KNAW Fungal Biodiversity Centre, P.O. Box 85167, 3508 AD Utrecht, The Netherlands.

Patterns in nutrient availability often vary both in space and time (e.g. Pegtel 1987; Stark 1994; Marschner 1995) and small differences can lead to large consequences in the ecophysiological responses and competitive abilities of plant species (Fitter 1982; Wedin & Tilman 1990; Grime 1994). Nevertheless the spatial scale and the degree of spatial heterogeneity and how this might differ among communities are poorly understood. Most plant individuals experience nutrient availability through their fungal partner. Different mycorrhiza types have some important ecological and physiological differences that may have important consequences for the competitive abilities of the associated plants. The impact of mycorrhiza networks relative to other mechanisms on the interaction between plant species remains unclear, but several experiments suggest a considerable influence, at least in some terrestrial ecosystems. In this review, we will discuss causes and consequences of soil heterogeneity, at spatial scales ranging from individual plants to the level of plant communities, in view of their impact on competition and coexistence. A similar approach will be applied to the issue of effects of mycorrhizal fungi, asking the question whether they intensify interspecific competition or facilitate coexistence.

Black pigmented conidia of Aspergillus niger give rise to micro-colonies when incubated in liquid shaken medium. These micro-colonies are heterogeneous with respect to gene expression and size. We here studied the biophysical properties of the conidia of a control strain and of strains in which the fwnA, olvA or brnA gene is inactivated. These strains form fawn-, olive-, and brown-coloured conidia, respectively. The δolvA strain produced larger conidia (3.8 μm) when compared to the other strains (3.2-3.3 μm). Moreover, the conidia of the δolvA strain were highly hydrophilic, whereas those of the other strains were hydrophobic. The zeta potential of the δolvA conidia in medium was also more negative when compared to the control strain. This was accompanied by the near absence of a rodlet layer of hydrophobins. Using the Complex Object Parametric Analyzer and Sorter it was shown that the ratio of individual hyphae and micro-colonies in liquid shaken cultures of the deletion strains was lower when compared to the control strain. The average size of the micro-colonies of the control strain was also smaller (628 μm) than that of the deletion strains (790-858 μm). The size distribution of the micro-colonies of the δfwnA strain was normally distributed, while that of the other strains could be explained by assuming a population of small and a population of large micro-colonies. In the last set of experiments it was shown that relative expression levels of gpdA, and AmyR and XlnR regulated genes correlate in individual hyphae at the periphery of micro-colonies. This indicates the existence of transcriptionally and translationally highly active and lowly active hyphae as was previously shown in macro-colonies. However, the existence of distinct populations of hyphae with high and low transcriptional and translational activity seems to be less robust when compared to macro-colonies grown on solid medium. © CBS-KNAW Fungal Biodiversity Centre, P.O. Box 85167, 3508 AD Utrecht, The Netherlands.

There is growing evidence of the importance of extramatrical mycelium (EMM) of mycorrhizal fungi in carbon (C) cycling in ecosystems. However, our understanding has until recently been mainly based on laboratory experiments, and knowledge of such basic parameters as variations in mycelial production, standing biomass and turnover as well as the regulatory mechanisms behind such variations in forest soils is limited. Presently, the production of EMM by ectomycorrhizal (EM) fungi has been estimated at ~140 different forest sites to be up to several hundreds of kg per ha per year, but the published data are biased towards Picea abies in Scandinavia. Little is known about the standing biomass and turnover of EMM in other systems, and its influence on the C stored or lost from soils. Here, focussing on ectomycorrhizas, we discuss the factors that regulate the production and turnover of EMM and its role in soil C dynamics, identifying important gaps in this knowledge. C availability seems to be the key factor determining EMM production and possibly its standing biomass in forests but direct effects of mineral nutrient availability on the EMM can be important. There is great uncertainty about the rate of turnover of EMM. There is increasing evidence that residues of EM fungi play a major role in the formation of stable N and C in SOM, which highlights the need to include mycorrhizal effects in models of global soil C stores. Skupno št. avtorjev: 14. Bibliografija: str. 21-27.

International audience; The biomass of 18 strains of Agaricus subrufescens and of 13 strains of Agaricus bisporus was chemically analyzed using solid-state 13 C NMR. The study focused on polysaccharides because they can play a major role as antitumor molecules. The study also examined whether biomass chemical properties varied between the vegetative mycelium and the fruiting bodies of A. subrufescens, and these data were compared with the mycelium of A. bisporus. Qualitative differences between vegetative mycelia and fruiting bodies were observed, whereas quantitative differences were measured between the two species with a higher percentage of polysaccharides in the biomass of A. subrufescens. This Agaricus species is thus an interesting potential source of polysaccharides with medicinal properties, both from vegetative mycelium obtained in liquid cultures and from fruiting bodies produced on composts.

The king oyster mushroom ( Pleurotus eryngii) is more and more popular amongst the producers due to its excellent taste and relatively easy cultivation . In the course of our work we collected 15 king oyster mushroom strains from various habitats in Hungary in order to get a better picture about the growth of the vegetative mycelia of the species and its different strains. In the in vitro experiments we investigated the growth of the strains at various temperatures and pH. incubated them in light and darkness and in aerobic and anaerobic atmosphere. In addition to these we measured the weight of dry mycelia produced in a given time by the strains. Our results showed that the above mentioned environmental conditions resulted in a very different growth rate of the vegetative mycelia of the various P. eryngii strains. These results may provide valuable data about the vegetative phase of the cultivation.

WOS: 000259300300006 In this study, the effects of various carbon sources for Morchella conica sclerotium formations were investigated under in vitro conditions. The formations of sclerotial initials, which improved from hyphae of Morchella conica, were obtained by using different carbohydrates. Vegetative mycelia were developed very well in agar media, containing malt extract (MEA), wheat (WA), potato dextrose (PDA) and complete medium yeast extract (CYM), however, moderate development occurred in defined media, containing glucose, sucrose, maltose and starch. The carbohydrate concentrations were prepared as 0.0%, 0.25%, 0.50%, 0.75%, 1.00% and 1.25%. Whole wheat agar and potato dextrose agar media consisting of glucose, sucrose and 0.25%, 0.75% and 1.25% starch excluded, while other cultural environments supported sclerotial formations. Sclerotial structures were examined morphologically and anatomically. The pigmentation changed from yellow to orange and brown. Time sclerotial formation varied from 10 days up to 7 months. Pigmentation, structure and quantity of sclerotia were taken as morphological criteria. Anatomical properties of sclerotia were obtained on light microscopy and scanning electron microscopy. Generally, sclerotial cells were very thick and spherical.