An overview of Agaricus section Hondenses and Agaricus section Xanthodermatei with description of eight new species from Pakistan.

In a recent revision of the genus Agaricus, A. section Xanthodermatei was split into two sections A. sect. Hondenses and A. sect. Xanthodermatei. Our objectives were to investigate the species diversity of both sections in Pakistan and to give an overview of the major clades. Phylogenetic analyses based on the combined nucLSU, ITS and TEF1 dataset from 35 specimens of both sections revealed three major clades. Analyses based on ITS dataset and 106 specimens, including 33 from Pakistan, reveal eight new species and one new record species. These nine species are described in detail. It is noteworthy that intraspecific variability as well as interspecific variability between closely related species were very low in ITS sequences in many cases. In the case of the two new species A. xanthochromaticus and A. griseovariegatus, TEF1 sequence data were much more efficient than ITS to distinguish these species from each other. The other new species are A. atroumbonatus, A. fumidicolor, A. macropeplus, A. parviniveus, A. swaticus and A. bambusetorum. The latter is the only new species of A. sect. Hondenses in which it is morphologically atypical and also the unique (sub)tropical species. Agaricus gregariomyces is recorded for the first time in Pakistan. In addition, brief descriptions are provided not only for A. bisporiticus, A. endoxanthus and A. punjabensis, which are reported again in Pakistan, but also for A. californicus, which is reported for the first time in Spain and outside North America. In total 12 species of both sections were reported in Pakistan and half of them were from subtropical climatic areas, underlining the contribution of the climatic diversity to the high species richness in this country.

Preparation and characterization of various chitin-glucan complexes derived from white button mushroom using a deep eutectic solvent-based ecofriendly method.

Deep eutectic solvents (DESs) have gained great interests as ecofriendly and safe solvents in diverse areas. Herein, various chitin-glucan complexes (CGCs) were prepared from white button mushroom (Agaricus bisporus) using DESs. Ultrasonication of mushroom in five DESs yielded two types of CGCs from each DES, one from the DES-insoluble residue (DES_P) and another from the DES-soluble extract (DES_S). The ten resulting CGCs with varying chitin-to-ß-glucan ratios were compared with alkali-insoluble matter (AIM), chemically prepared using NaOH. BU_S and BU_P, prepared using BU comprising betaine and urea, were obtained in the highest yields with reasonably low protein and mineral contents. Despite different acetylation degrees (77.3% and 57.3%, respectively), BU_S and BU_P both degraded at 318 °C and showed remarkably low crystallinity (32.0% and 37.0% for BU_S and BU_P, respectively) compared to AIM, commercial chitin, and the reported CGCs. The surface of BU_S and BU_P was very porous and rough compared with AIM as a result of reduced H-bonds and lowered crystallinity. The DES-based method can potentially enable the preparation of advanced biomaterials from mushrooms under mild and ecofriendly conditions.

North American matsutake: names clarified and a new species described.

Tricholoma matsutake, known widely as "matsutake," has great commercial and cultural significance in Japan. Because Japanese production is insufficient to meet the high domestic demand, morphologically similar mushrooms, thought by many to belong to T. magnivelare, are imported from western North America. However, molecular data produced since the early 2000s have indicated that more than one species of matsutake occur in North America and this raises the question of correct naming for the different species. To address this question, we assessed the phylogenetic diversity within North American matsutake based on nuc rDNA ITS1-5.8S-ITS2 (internal transcribed spacer [ITS] barcode) sequences, including newly obtained sequences from the type collections for Agaricus ponderosus and Armillaria arenicola, and morphological characters. Our results agree with earlier indications that three matsutake species occur in North America and allow us to clarify the correct application of names-T. magnivelare from the eastern USA and Canada, T. murrillianum from the western USA and Canada, and T. mesoamericanum from Mexico, newly described here. The existence of the three North American species is further supported by the results of evolutionary divergence analysis, geographical distributions, and morphological characters.

Flammulina velutipes: an option for 'alperujo' use / Flammulina velutipes: una opción para el aprovechamiento del alperujo

Background. Two-phase olive-mill wastes (or 'alperujo') exhibit highly phytotoxic properties, mainly due to phenols. A valuable option for alperujo is its agricultural use, provided that no phytotoxic effects occur. Aims. The present investigation was aimed at evaluating the efficacy of two strains of the lignin-degrading fungus Flammulina velutipes to colonize alperujo in order to produce edible mushrooms and to achieve its detoxification. Methods. Some important cultural characters related to mushroom production (earliness, biological efficiency and quality of basidiomes) were estimated. The production of lignocellulolytic enzymes, phenol removal and detoxification of the substrate was evaluated. Results. High biological efficiencies (70.8%) were obtained at 12°C with F. velutipes strain BAFC 670/06 in a substrate containing poplar wood shavings and 90% of alperujo. The nature of the substrate did not seem to exert an important influence on pileus and stem morphology; nevertheless shortest stems were observed at higher temperatures. Endo-β-1,4-glucanase, endo-β-1,4-xylanase, laccase and Mn-peroxidase activities were detected in the extracts recovered from the solid-state cultures. Both F. velutipes strains were effective in removing the phenolic compounds. The initial concentration in the substrate with 90% alperujo was reduced in the case of F. velutipes BAFC 1763 by 84.31%, and 40.15% by F. velutipes BAFC 670/06. Germinability experiments on Raphanus sativus, showed that alperujo phytotoxicity was significantly reduced by F. velutipes cultures. Conclusions. The experimented changes by the spent mushroom substrate resulting from F. velutipes cultivation with high amount of alperujo would allow its reuse for agricultural purposes (AU)

Antecedentes. El alperujo, subproducto de las almazaras durante la extracción del aceite de oliva, tiene propiedades fitotóxicas importantes debido a su alto contenido fenólico. Su utilización en la agricultura es una opción válida, pero deben eliminarse sus efectos fitotóxicos. Objetivos. El objetivo de este trabajo fue evaluar la eficacia de dos cepas del hongo ligninolítico Flammulina velutipes de crecer en sustratos con alto contenido de alperujo, detoxificarlo y producir basidiomas comestibles. Métodos. Se estudiaron las principales características relacionadas con el cultivo para la producción de basidiomas: tiempo de aparición de primordios, eficiencia biológica y calidad. Se evaluó la producción de enzimas lignocelulolíticas, la remoción de compuestos fenólicos y la detoxificación del sustrato. Resultados. Se obtuvieron altos valores de eficiencia biológica (70,8%) a 12°C con la cepa BAFC 670/06 de F. velutipes en un sustrato compuesto de viruta de álamo y 90% de alperujo. La naturaleza del sustrato al parecer no ejerció influencias importantes en la morfología de los basidiomas, aunque a altas temperaturas los estípites presentaron una menor longitud. Se detectó actividad endo-β-1,4-glucanasa, endo-β-1,4-xilanasa, lacasa y Mn-peroxidasa en extractos recuperados de cultivos en estado sólido. Ambas cepas fueron efectivas en la reducción del contenido de fenoles del sustrato, reducción que alcanzó el 84,31% con F. velutipes BAFC 1763 y el 40,15% con F. velutipes BAFC 670/06. Los ensayos de germinación de semillas de Raphanus sativus mostraron una significativa reducción de la fitotoxicidad del alperujo. Conclusiones. Los cambios experimentados por el sustrato remanente del cultivo de F. velutipes con altas concentraciones de alperujo podrían permitir su reutilización con fines agrícolas (AU)

Hepatoprotective effects of polysaccharide isolated from Agaricus bisporus industrial wastewater against CCl4-induced hepatic injury in mice.

During the industrial production of canned mushroom (Agaricus bisporus), a large quantity of wastewater is produced. In this study, the wastewater generated during the canning of mushroom was analyzed. From this wastewater, four polysaccharide components (Abnp1001, Abnp1002, Abap1001, and Abap1002) with hepatic-protective activity were isolated by ultrafiltration, DEAE cellulose-52 chromatography and Sephadex G-200 size-exclusion chromatography. Results of ultraviolet spectra analysis and molecular weight determination showed that Abnp1001, Abnp1002, Abap1001 and Abap1002 were uniform with average molecular weights of 336, 12.8, 330 and 15.8kDa, respectively. The monosaccharide composition analysis using gas chromatography (GC) showed that the four fractions were heteropolysaccharides and mainly composed of glucose. Fourier transform-infrared (FT-IR) analysis showed that the isolated fractions were all composed of ß-glycoside linkages. Additionally, the potential hepatoprotective activities of these polysaccharides against CCl4-induced hepatic injury in mice were studied. Notably, Abnp1002 and Abap1002 could lower the alanine aminotransferase (ALT) and aspartate aminotransferase (AST) concentrations in serum in a dose dependent manner and reduce the hepatocellular degeneration and necrosis, as well as inflammatory infiltration. These results indicate that these two polysaccharides had protective effects on acute hepatic injury induced by CCl4 in mice and suggest that the polysaccharides extracted from A. bisporus industrial wastewater might have potential in therapeutics of acute hepatic injury.

Agaricus section Arvenses: three new species in highland subtropical Southwest China.

Agaricus is a genus of saprobic basidiomycetes with more than 400 species recognized worldwide, with about 50 species known in China. Our objective was to investigate three new species of section Arvenses in highland subtropical Southwest China. Agaricus guizhouensis is a new species characterized by a white pileus with yellowish squamules, small ellipsoid spores and cheilocystidia with yellowish-brown pigments; another new species, Agaricus longistipes is recognized by its slender stipe, and its elongate-ellipsoid basidiospores; the third new one, Agaricus megalocarpus is remarkable by its large size and its pileus surface covered with fine brown squamules. It is firstly reported for Guizhou Province that Agaricus abruptibulbus, Agaricus flocculosipes, and Agaricus subrufescens are illustrated. Two probable new species require further studying. A phylogenetic analyses of rDNA-ITS sequence data belonging to section Arvenses showed that the section Arvenses is monophyletic and can be subdivided in five branches, the branch of A. subrufescens and four clades (A-D). The eight species from highland subtropical Southwest China were distributed in all five branches, indicating that this highland is at the climatic crossroads. The white pileus trait and the potential interest are discussed. These data suggest a potential species richness that remains to be discovered.

Selected wild strains of Agaricus bisporus produce high yields of mushrooms at 25 °C / Cepas silvestres seleccionadas de Agaricus bisporus con capacidad para producir un alto rendimiento a temperaturas de 25°C

Background. To cultivate the button mushroom Agaricus bisporus in warm countries or during summer in temperate countries, while saving energy, is a challenge that could be addressed by using the biological diversity of the species. Aims. The objective was to evaluate the yield potential of eight wild strains previously selected in small scale experiments for their ability to produce mature fruiting bodies at 25 °C and above. Methods. Culture units of 8 kg of compost were used. The yield expressed as weight or number per surface unit and earliness of fruiting were recorded during cultivation in climatic rooms at 17, 25 or 30 °C. Results. Only strains of A. bisporus var. burnettii were able to fruit at 30 °C. At 25 °C they produced the highest yields (27 kg m−2) and had best earliness. The yields at 25 °C for the strains of A. bisporus var. bisporus ranged from 12 to 16 kg m−2. The yield ratios 25 °C/17 °C ranged from 0.8 to 1.2. Conclusions. The variety burnettii originated in the Sonoran Desert in California showed adaptation for quickly producing fruiting bodies at high temperature when humidity conditions were favorable. Strains of the variety bisporus showed interesting potentials for their ability to produce mature fruiting bodies at higher temperature than present cultivars and might be used in breeding programs (AU)

Antecedentes. El cultivo del champiñón (Agaricus bisporus) en países de clima tropical, o durante el verano en países de clima templado, además del ahorro energético que supone, es un reto que podría abordarse con el uso adecuado de la diversidad biológica de la especie. Objetivos. El objetivo del presente estudio fue examinar el rendimiento potencial de ocho cepas silvestres, previamente seleccionadas en experimentos a pequeña escala, para determinar su capacidad para producir frutos maduros a temperaturas ≥25 °C. Métodos. Se utilizaron unidades experimentales de cultivo con 8 kg de compost. El rendimiento se expresó como peso o número de frutos producidos por unidad de superficie; en naves climatizadas, a una temperatura de 17, 25 o 30 °C, durante todo el cultivo, se registró el momento de fructificación. Resultados. Sólo las cepas de A. bisporus var. burnettii fueron capaces de fructificar a 30 °C. Éstas produjeron un alto rendimiento a 25 °C (27 kg/m2) y la fructificación aconteció más temprano. El rendimiento a 25 °C para las cepas de A. bisporus var. bisporus varió de 12 a 16 kg/m2, con una proporción 25 °C/17 °C de 0,8 a 1,2. Conclusiones. La variedad burnettii, originaria del desierto de Sonora en California, está adaptada para producir cuerpos fructíferos a temperaturas elevadas cuando las condiciones de humedad son favorables. Para las cepas de la variedad bisporus se demostró un interesante potencial para producir cuerpos fructíferos maduros a una mayor temperatura que la utilizada en los cultivares actuales y puede ser utilizada en los programas de mejora genética (AU)

Evidence for amphithallism and broad geographical hybridization potential among Agaricus subrufescens isolates from Brazil, France, and Thailand.

Agaricus subrufescens is a cultivated edible and medicinal mushroom. Its known geographical distribution encompasses the Americas, Europe, Oceania, and Asia. The objective of this study was to assess mating compatibility and interfertility of strains originating from Brazil, France, and Thailand. Progeny of each strain were analyed with codominant molecular markers. Multilocus genotype tests revealed that the three strains were amphithallic with percentages of heterokaryotic single spore progenies of 75% for the Thai strain and around 40% for the Brazilian and French strains. In mating tests A. subrufescens had a multiallelic unifactorial system of sexual incompatibility. The three parent strains were interfertile based on experimental pairings of single-spore isolates, the recovery of hybrid heterokaryons from compatible matings, and the ability of hybrids to produce mushrooms and fertile spores. This biological approach supports the inclusion of the European strains within the species and the extension of the geographical distribution range to Asia. Our data should help to develop breeding strategies and to better manage and exploit the diversity existing in A. subrufescens.

Morphological and molecular characterization of three Agaricus species from tropical Asia (Pakistan, Thailand) reveals a new group in section Xanthodermatei.

The genus Agaricus is known for its medicinal and edible species but also includes toxic species that belong to section Xanthodermatei. Previous phylogenetic reconstruction for temperate species, based on sequence data of nuc rRNA gene (rDNA) internal transcribed spacers (ITS), has revealed two major groups in this section and a possible third lineage for A. pseudopratensis. Recent research in Agaricus has shown that classifications need improving with the addition of tropical taxa. In this study we add new tropical collections to section Xanthodermatei. We describe three species from collections made in Pakistan and Thailand and include them in a larger analysis using all available ITS data for section Xanthodermatei. Agaricus bisporiticus sp. nov. and A. fuscopunctatus sp. nov. are introduced based on molecular and morphological studies, whereas A. microvolvatulus is recorded for the first time in Asia. Specimens from Thailand however have a much larger pileus than the type specimens from Congo. In maximum likelihood (ML) and maximum parsimony (MP) phylogenetic analyses these three species cluster with A. pseudopratensis from the Mediterranean area and A. murinocephalus recently described from Thailand. In Agaricus section Xanthodermatei this new group is monophyletic and receives low bootstrap support whereas the two previously known groups receive strong support. Within the new group, the most closely related species share some traits, but we did not find any unifying morphological character; however the five species of the group share a unique short nucleotide sequence. Two putatively toxic species of section Xanthodermatei are now recognized in Pakistan and six in Thailand.

Adaptabilidad de cepas brasileñas de Agaricus subrufescens Peck a la fructificación sobre diferentes capas de cobertura en cultivo comercial / Adaptability of Brazilian strains of Agaricus subrufescens Peck to fruiting on various casing materials in commercial crops

Antecedentes. Agaricus subrufescens Peck es un hongo cuyo cultivo ha despertado gran interés en todo el mundo en los últimos años, adquiriendo gran popularidad. Sus propiedades medicinales y culinarias hacen prever una rápida expansión del cultivo en todo el mundo. Objetivos. El trabajo plantea como objetivo la evaluación del efecto sobre los principales parámetros de producción de 3 cepas de Agaricus subrufescens que se han hecho fructificar sobre 5 capas de cobertura diferentes. Métodos. Se ha llevado a cabo un ciclo de cultivo de Agaricus subrufescens en condiciones controladas en el que se han evaluado los principales parámetros de producción. Resultados. Los mejores resultados han sido proporcionados por la cepa ABL 99/30. Las coberturas basadas en turba presentan mejor comportamiento que las basadas en suelo mineral. El mayor rendimiento (6,75 kg/m−2, eficiencia biológica 27,57 kg/dt) ha sido proporcionado por la combinación ABL 99/30-Euroveen. Conclusiones. Nuestros resultados evidencian que la combinación de la cepa ABL 99/30 utilizando una capa de cobertura basada en turba (Euroveen) ofrece un alto potencial para ser utilizada a escala comercial por el sector productor de hongos. La disponibilidad de alternativas a las especies de hongos comestibles cultivadas habitualmente puede suponer un mejor aprovechamiento de recursos y una mayor rentabilidad económica de la actividad (AU)

Background. Agaricus subrufescens Peck is a mushroom whose cultivation has aroused great interest worldwide in recent years, and is becoming increasingly popular. A rapid expansion of culture throughout the world is foreseen because of its medicinal and culinary properties. Aims. This work assesses the effect of 5 different casing layers on the production of 3 strains of Agaricus subrufescens. Methods. A growth cycle of Agaricus subrufescens under controlled conditions has been carried out. The main production parameters were evaluated. Results. The best results were provided by the ABL 99/30 strain. Peat-based casings have a better yield than those based on mineral soil. The highest yield (6.75 kg/m2, biological efficiency 27.57 kg/dt) was provided by the combination ABL 99/30-Euroveen. Conclusions. Our results suggest that the combination of the strain ABL 99/30 using a peat-based casing layer (Euroveen) offers a high potential for use on a commercial scale by the edible mushroom production sector. The availability of alternatives to the usually cultivated species can make better use of resources, and increase the profitability of this activity (AU)

Characterization of single spore isolates of Agaricus bisporus (Lange) Imbach using conventional and molecular methods.

Strains A-15, S11, S-140, and U3 of Agaricus bisporus (Lange) Imbach, were used as parent strains for raising single spore homokaryotic isolates. Out of total 1,642 single spore isolates, only 36 single spore isolates were homokaryons and exhibited slow mycelial growth rate (≤2.0 mm/day) and appressed colony morphology. All these SSIs failed to produce pinheads in Petri plates even after 65 days of incubation, whereas the strandy slow growing SSIs along with parent strains were able to form the fructification in petriplates after 30 days. Out of 24, six ISSR primers, exhibited scorable bands. In the ISSR fingerprints, single spore isolates, homokaryons, lacked amplification products at multiple loci; they grow slowly and all of them had appressed types of colony morphology. The study revealed losses of ISSR polymorphic patterns in non-fertile homokaryotic single spore isolates compared to the parental control or fertile heterokaryotic single spore isolates.

Preservación de cepas de Agaricus subrufescens a bajas temperaturas con cultivos en semillas de sorgo / Preservation of Agaricus subrufescens strains at low temperature by using cultures on sorghum grains

Antecedentes. Uno de los principales problemas para la preservación de los recursos genéticos de Agaricus subrufescens es mantener la viabilidad de sus cepas ya que el micelio es sensible al frío y, en consecuencia, envejece rápidamente. Objetivos. Evaluar la viabilidad de cepas de A. subrufescens y cepas de Agaricus bisporus en cultivos en semillas de sorgo a diferentes temperaturas. Métodos. Se estudiaron 18 cepas de A. subrufescens y 3 cepas de A. bisporus. Se evaluó la viabilidad de A. subrufescens en las condiciones siguientes: (1) control a 25°C (C), (2) enfriamiento hasta 4°C (E) y (3) congelación en nitrógeno líquido a −196°C (NL). Las muestras se recuperaron a las 4, 6, 8, 10, 12 y 24 semanas en C y E, mientras que en NL se recuperaron a las 4, 12 y 24 semanas. La viabilidad se evaluó en 50 semillas, por cepa y condición, en placas de Petri con medio de agar patata dextrosa (APD). También se evaluó el crecimiento de los micelios en APD tras obtención a los 14 días. Resultados. La mayoría de cepas mostraron un 100% de viabilidad, y en general, se obtuvieron en 24h. En la condición NL la viabilidad varió entre el 84 y el 100%, pero en algunos casos su obtención requirió > 10 días. El crecimiento de los micelios se redujo gradualmente con el tiempo y, aunque los resultados indicaron diferencias significativas entre los tratamientos C y E, este declive se asocia al envejecimiento del micelio más que al propio tratamiento. Conclusiones. El cultivo en semillas de sorgo y el almacenamiento a bajas temperaturas es un medio eficaz para preservar los recursos genéticos de A. subrufescens(AU)

Background. One of the main problems for the preservation of genetics resources of Agaricus subrufescens is to maintain the viability of the strains because the mycelium is very sensitive to cooling and therefore it ages rapidly. Aims. Evaluate the viability of A. subrufescens strains stored as cultures on sorghum grain (spawn) at different temperatures. Methods. Eighteen strains of A. subrufescens and three strains of Agaricus bisporus were studied. Spawn's viability was evaluated under the following conditions: (1) control at 25°C (C), (2) cooling to 4°C (R) and (3) freezing in liquid nitrogen at −196°C (LN). Samples were recovered from week 4 every 2 weeks until week 12 and week 24 in C and R, whereas in LN samples were recovered at 4, 12 and 24 weeks. Viability was evaluated in 50 seeds, by strain and condition, recovering the mycelium in Petri dishes with potato dextrose agar medium (PDA). Mycelium growth was also evaluated on PDA after 14 days of recovery. Results. Most strains showed 100% viability and they were recovered usually in 1 day. In LN the viability ranged between 84 and 100% depending on the strain, but in some cases recovery took more than 10 days. Mycelial growth decreased gradually over time and although the results show significant differences between treatments C and R, the decline is associated with ageing of the mycelium rather than the treatment itself. Conclusions. Culture on sorghum grain and storage at low temperature is an interesting way to preserve genetic resources of A. subrufescens(AU)

Effects of Agaricus lilaceps fairy rings on soil aggregation and microbial community structure in relation to growth stimulation of western wheatgrass (Pascopyrum smithii) in Eastern Montana rangeland.

Stimulation of plant productivity caused by Agaricus fairy rings has been reported, but little is known about the effects of these fungi on soil aggregation and the microbial community structure, particularly the communities that can bind soil particles. We studied three concentric zones of Agaricus lilaceps fairy rings in Eastern Montana that stimulate western wheatgrass (Pascopyrum smithii): outside the ring (OUT), inside the ring (IN), and stimulated zone adjacent to the fungal fruiting bodies (SZ) to determine (1) soil aggregate proportion and stability, (2) the microbial community composition and the N-acetyl-ß-D-glucosaminidase activity associated with bulk soil at 0-15 cm depth, (3) the predominant culturable bacterial communities that can bind to soil adhering to wheatgrass roots, and (4) the stimulation of wheatgrass production. In bulk soil, macroaggregates (4.75-2.00 and 2.00-0.25 mm) and aggregate stability increased in SZ compared to IN and OUT. The high ratio of fungal to bacteria (fatty acid methyl ester) and N-acetyl-ß-D-glucosaminidase activity in SZ compared to IN and OUT suggest high fungal biomass. A soil sedimentation assay performed on the predominant isolates from root-adhering soil indicated more soil-binding bacteria in SZ than IN and OUT; Pseudomonas fluorescens and Stenotrophomonas maltophilia isolates predominated in SZ, whereas Bacillus spp. isolates predominated in IN and OUT. This study suggests that growth stimulation of wheatgrass in A. lilaceps fairy rings may be attributed to the activity of the fungus by enhancing soil aggregation of bulk soil at 0-15 cm depth and influencing the amount and functionality of specific predominant microbial communities in the wheatgrass root-adhering soil.

Agaricus bisporus and related Agaricus species on lignocellulose: production of manganese peroxidase and multicopper oxidases.

Biotechnological, microbiological, and genetic studies of Agaricus species other than A. bisporus, the white button mushroom, have been limited so far. To expand the knowledge in the genus Agaricus, six novel wild-type isolates of Agaricus spp. were studied on their nutritional demands for enzyme production and mycelial growth. All the selected Agaricus species produced extracellular manganese peroxidase (MnP) and laccase activities in semi-solid rye bran cultures. Moderate MnP activities were measured for A. bisporus, A. bernardii and A. campestris. The highest laccase activities were obtained for A. bisporus and A. campestris. On soy medium, the highest mycelial tyrosinase activity was determined for A. bernardii. For A. bisporus, addition of copper caused no increase in laccase or tyrosinase activities on soy or malt extract media. Hyphal growth rate of the isolates was studied on lignocellulose amended agar plates. Fastest growth was obtained for A. bisporus on wheat bran and birch leaf litter agar. Except for A. bernardii, hyphal growth rates correlated well with MnP and laccase production levels between Agaricus species. Molecular taxonomy of the novel Agaricus spp. positioned them to distinct phylogenetic clusters with species-level identity. In conclusion, our data point to the importance of both MnP and multicopper enzymes in Agaricus spp. while growing on lignocelluloses.

Capacity for colonization and degradation of horse manure and wheat-straw-based compost by different strains of Agaricus subrufescens during the first two weeks of cultivation.

The potential of Agaricus subrufescens strains to colonize and transform horse manure and wheat-straw-based mushroom compost under the physico-chemical conditions typically used for Agaricus bisporus was assessed. Lignocellulolytic activities, H2O2 production and substrate transformation (assessed via CP/MAS NMR of (13)C) for certain A. subrufescens strains were similar or even greater than those obtained for an A. bisporus strain used as control. Moreover, the functional diversity of the microbial communities of the substrate was not altered by the growth of A. subrufescens after 2weeks. These findings obtained with mesocosms simulating the incubation phase of the mushroom production process hold promise for the improvement of cultivation of this tropical Agaricus species on European standard mushroom compost.

Cultivo biotecnológico de macrohongos comestibles: una alternativa en la obtención de nutracéuticos / Biotechnological cultivation of edible macrofungi: an alternative for obtaining nutraceutics

Los macromicetos han sido parte de la cultura humana desde hace miles de años y aparecen descritos como alimento humano en las más importantes civilizaciones de la historia. Se han descrito muchísimas propiedades nutricéuticas de los macromicetos, como sus propiedades anticancerígenas y antitumorales, hipocolesterolémicas, antivirales, antibacterianas, o inmunomoduladoras, entre otras. Dado que la producción de hongos por cultivo tradicional y la extracción de los metabolitos bioactivos en algunos casos son muy dispendiosas, la biotecnología es fundamental para el desarrollo de técnicas rentables y productivas para la obtención de estos metabolitos. Es el desarrollo de esta tecnología y la facilidad que proporciona en cuanto al manejo de sus variables, lo que ha permitido realizar el cultivo en medio líquido del micelio de macrohongos con significativa reducción de tiempo y aumento en la producción de sus metabolitos, lo que ha impulsado aún más su obtención y el estudio de compuestos con potencial como medicamentos, nutricéuticos y cuasifarmacéuticos tanto del medio agotado como del micelio. El objetivo de esta revisión es el de ofrecer una visión general de la utilización de la fermentación en estado líquido como herramienta tecnológica para la obtención de hongos comestibles, su estudio y el de sus bioactivos, mediante la descripción de las diferentes condiciones de cultivo que en los últimos años se han empleado, así como los resultados obtenidos. Se discutirá lo correspondiente a los géneros Agaricus, Flammulina, Grifola, Pleurotus y Lentinula, con énfasis en este último, dado que el Shiitake ha sido considerado desde siempre como el hongo medicinal por excelencia(AU)

Macromycetes have been part of the human culture for thousand years, and have been reported as food in the most important civilizations in history. Many nutraceutical properties of macromycetes have been described, such as anti-cancer, anti-tumour, cholesterol lowering, antiviral, antibacterial, or immunomodulatory, among others. Given that production of mushrooms by traditional cultivation and extraction of bioactive metabolites is very difficult in some cases, biotechnology is essential for the development of profitable and productive techniques for obtaining these metabolites. It is the development of this technology, and the ease in which it enables the use of its variables that has allowed mycelium to be cultivated in liquid medium of macrofungi, with a significant reduction in time and an increased production of metabolites. This increased production has led to the study of compounds that have medicinal, nutriceutical and quasi-farmaceutical potential, in the exhausted media and the mycelium. The aim of this review is to provide an overview of the use of liquid-state fermentation as a technological tool for obtaining edible fungi, and the study of these and their metabolites, by describing the different cultivation conditions used in recent years, as well as the results obtained. The relevance of Agaricus, Flammulina, Grifola, Pleurotus and Lentinula genera, will also be discussed, with emphasis on the last one, since Shiitake has been always considered as the ultimate medicinal mushroom(AU)

Mitochondrial recombination in natural populations of the button mushroom Agaricus bisporus.

In the majority of sexual eukaryotes, the mitochondrial genomes are inherited uniparentally and have predominantly clonal population structures. In clonally evolving genomes, alleles at different loci will be in significant linkage disequilibrium. In this study, the associations among alleles at nine mitochondrial loci were analyzed for 379 isolates in four natural populations of the button mushroom Agaricus bisporus. The results indicated that the mitochondrial genome in the Desert California population was not significantly different from random recombination. In contrast, the three other populations all showed predominantly clonal mitochondrial population structure. While no evidence of recombination was found in the Alberta, Canada A. bisporus population, signatures of recombination were evident in the Coastal Californian and the French populations. We discuss the potential mechanisms that could have contributed to the observed mitochondrial recombination and to the differences in allelic associations among the geographic populations in this economically important mushroom.

Pathogenic variation in isolates of Pseudomonas causing the brown blotch of cultivated mushroom, Agaricus bisporus

Twenty seven bacterial isolates were isolated from superficial brown discolorations on the caps of cultivated Agaricus bisporus. After White Line Assay (WLA) and the assist of Biolog computer-identification system, isolates were divided into groups: (I) comprised ninteen bacterial isolates that positively responded to a Pseudomonas "reactans" reference strain (NCPPB1311) in WLA and were identified as Pseudomonas tolaasii, (II) comprised two isolates which were WLA+ towards the reference strain (JCM21583) of P. tolaasii and were proposed to be P. "reactans". The third group comprised six isolates, two of which weakly responded to the strain of P. tolaasii and were identified as P. gingeri whereas the other four were WLA- and identified as P. fluorescens (three isolates) and P. marginalis (one isolate). Isolates of P. tolaasii showed high aggressiveness compared with those of P. "reactans" in pathogenicity tests. Cubes of 1 cm³ of A. bisporus turned brown and decreased in size when were inoculated with 10 µl of P. tolaasii suspension containing 10(8) CFU ml-1, whereas a similar concentration of P. "reactans" caused only light browning. Fifty µl of the same concentration of P. tolaasii isolates gave typical brown blotch symptoms on fresh mushroom sporophores whereas the two P. "reactans" isolates caused superficial light discoloration only after inoculation with 100 µl of the same concentration. Mixture from both bacterial suspensions increased the brown areas formed on the pileus. This is the first pathogenicity report of P. tolasii and P. "reactans" isolated from cultivated A. bisporus in Egypt.

Diversity in the ability of Agaricus bisporus wild isolates to fruit at high temperature (25°C).

The button mushroom Agaricus bisporus commercially cultivated requires 16-19 °C during the fruiting period. Wild strains are also present in natural habitat, and in light of their wide range of geographic distribution reported, from boreal region to tropical region, questions on the development adaptation to temperature arose. Isolates from various geographic areas were screened for their ability to fruit at higher temperature (FHT ability) than commercial cultivars. The FHT trait discriminated at the varietal rank. Agaricus bisporus var. eurotetrasporus was unable to develop any sporophores whilst A. bisporus var. burnettii adapted perfectly to 25 °C for fruiting, suggesting that the FHT ability is a fixed trait in these varieties. In contrast, FHT ability of A. bisporus var. bisporus appeared variable and correlated neither with climate/microclimate nor with habitat. However, FHT ability taken as a whole appeared higher in North American populations than in European ones. Some A. bisporus var. bisporus isolates revealed a good potential for cultivation at 25 °C.

Characterization of cellobiohydrolase from a newly isolated strain of Agaricus arvencis.

A highly efficient cellobiohydrolase (CBH)-secreting basidiomycetous fungus, Agaricus arvensis KMJ623, was isolated and identified based on its morphological features and sequence analysis of internal transcribed spacer rDNA. An extracellular CBH was purified to homogeneity from A. arvencis culture supernatant using sequential chromatography. The relative molecular mass of A. arvencis CBH was determined to be 65 kDa by SDSPAGE and 130 kDa by size-exclusion chromatography, indicating that the enzyme is a dimer. A. arvencis CBH showed a catalytic efficiency (kcat/Km) of 31.8 mM⁻¹ s⁻¹ for p-nitrophenyl-beta-D-cellobioside, the highest level seen for CBH-producing microorganisms. Its internal amino acid sequences showed significant homology with CBHs from glycoside hydrolase family 7. Although CBHs have been purified and characterized from other sources, A. arvencis CBH is distinguished from other CBHs by its high catalytic efficiency.