Linking the protease activity to the nematicidal action of edible mushroom.

Biological control using edible mushrooms as natural enemies is a sustainable alternative for pest management. Despite the well-established literature on toxins and secondary metabolites produced by these fungi in the biochemical control of nematodes, the nematicidal activity of proteases from different Pleurotus species is yet to be investigated. Therefore, this study aimed to correlate protease to the nematicidal activity of different mushrooms, Pleurotus sp., P. ostreatus (SB), P. ostreatus (Pearl), and P. djamor. For such a purpose, we performed motility assays of Panagrellus sp. at different time intervals, 6, 12, and 24 h for each of the mushrooms. In addition, the protease activity was measured using different pH (5, 7, and 9) and fermentation time intervals (45 and 75 days). Furthermore, we also evaluated the effect of this cell-free extract on Panagrellus sp. In response to these experiments, all edible mushrooms showed a reduction over 82% for the nematode-feeding activity (p < 0.01). The cell-free crude extract of each of the fungi studied showed nematocidal activity (p < 0.01). For the 45-day fermentation, P. djamor exhibited statistical significance (p < 0.01) compared with the others, reaching a reduction percentage of 73%. For the 75-day fermentation, Pleurotus sp. and P. ostreatus (Pearl) showed significant differences compared with the other fungi (p < 0.01), with reduction percentages of 64 and 62%, respectively. Herein, protease activity was associated with the nematicidal action of different Pleurotus species in controlling Panagrellus sp.

Decoding the chromosome-scale genome of the nutrient-rich Agaricus subrufescens: a resource for fungal biology and biotechnology.

Agaricus subrufescens, also known as the "sun mushroom," has significant nutritional and medicinal value. However, its short shelf life due to the browning process results in post-harvest losses unless it's quickly dehydrated. This restricts its availability to consumers in the form of capsules. A genome sequence of A. subrufescens may lead to new cultivation alternatives or the application of gene editing strategies to delay the browning process. We assembled a chromosome-scale genome using a hybrid approach combining Illumina and Nanopore sequencing. The genome was assembled into 13 chromosomes and 31 unplaced scaffolds, totaling 44.5 Mb with 96.5% completeness and 47.24% GC content. 14,332 protein-coding genes were identified, with 64.6% of the genome covered by genes and 23.41% transposable elements. The mitogenome was circularized and encoded fourteen typical mitochondrial genes. Four polyphenol oxidase (PPO) genes and the Mating-type locus were identified. Phylogenomic analysis supports the placement of A. subrufescens in the Agaricomycetes clade. This is the first available genome sequence of a strain of the "sun mushroom." Results are available through a Genome Browser (https://plantgenomics.ncc.unesp.br/gen.php?id=Asub) and can support further fungal biological and genomic studies.

Aqueous Extracts of Fermented Macrofungi Cultivated in Oilseed Cakes as a Carbon Source for Probiotic Bacteria and Potential Antibacterial Activity.

Plant biomass colonized by macrofungi can contain molecules with bioactive properties with applications to human/animal health. This work aimed to verify antibacterial activities from aqueous extracts from oil seed cakes of Jatropha curcas (JSC) and cottonseed (CSC), fermented by macrofungi for probiotic bacteria cultivation. Coriolopsis sp., Tyromyces sp., Panus lecomtei, and Pleurotus pulmonarius were cultivated in solid and submerged media. The aqueous extract of unfermented JSC was more efficient than glucose for the growth of all probiotic bacteria. Extracts from four macrofungi fermented in CSC favored Lactobacillus acidophilus growth. In solid fermentation, macrofungi extracts cultivated in JSC favored Bifidobacterium lactis growth. All fungi extracts showed more significant growth than carbohydrates among the four probiotic bacteria evaluated. Regarding antimicrobial activities, no fungal extract or bacterial supernatant showed a more significant inhibition halo for enteropathogenic bacteria than ampicillin (control). Extracts from P. lecomtei and Coriolopsis sp. in CSC showed inhibition halos for Salmonella enterica. Supernatants from L. acidophilus, B. lactis, and Lactobacillus rhamnosus resulted in more significant inhibition of Staphylococcus aureus than the control, which indicates possible antimicrobial activity. Unfermented JSC supernatant showed better results for bacterial growth, while supernatants and aqueous extracts from CSC fermentation can be used for probiotic bacteria culture.

Bioactives and Extracellular Enzymes Obtained from Fermented Macrofungi Cultivated in Cotton and Jatropha Seed Cakes.

This work focused on obtaining fermented oil cake (cotton or Jatropha) via macrofungi growth with potential characteristics for animal feed formulations, such as the presence of extracellular enzymes, bioactive (ergosterol and antioxidants), and detoxification of antinutritional compounds. The concentration of phorbol esters was reduced by four macrofungi in Jatropha seed cake (JSC) to non-toxic levels. At least two macrofungi efficiently degraded free gossypol in cottonseed cake (CSC). Fermentation with Coriolopsis sp. INPA1646 and Tyromyces sp. INPA1696 resulted in increased ergosterol concentrations, antioxidant activity reduction, and high activity of laccases and proteases. Bromatological analysis indicated high crude protein concentrations, with partial solubilization by fungal proteases. Fermented products from Coriolopsis sp. and Tyromyces sp. in JSC or CSC can be considered important biological inputs for monogastric and polygastric animal feed.

Spent mushroom substrate is capable of physisorption-chemisorption of CO2.

No in-depth investigation exists on the feasibility of integrating hydrothermal carbonization (HTC) and pelletization into the process of making spent mushroom substrate (SMS), an agro-food residue from the commercial mushroom industry, into an adsorbent for post-combustion CO2 removal. Therefore, this study analyzed if it could be possible for systematically converting low-pressure hydrochars of various SMSs into carbon-adsorbing mini-capsules. Sources of SMS included paddy straw and achiote capsule shell from Pleurotus ostreatus; eucalyptus sawdust and grassy straw from Lentinula edodes; and compost containing peat or soil as casing layer from Agaricus subrufescens. The eucalyptus sawdust and grassy straw from L. edodes outperformed the other biomaterials in adsorbing CO2, and thus effectively encapsuled most of the gas, 8.25 mmol g-1 and 8.10 mmol g-1, respectively. They contained mostly hetero-atoms of O and N, requiring less unit energy to bind acidic molecules of CO2 at the alkaline sites. The amount of unit energy the pore-filling process demanded at 25 °C was 12.65 kJ mol-1, an attribute of self-sustaining and saleable physisorption. A negative 6.80 kJ mol-1 free energy validated both spontaneity and exothermal of biocarbons at steady-state atmosphere. The major findings and innovations of our study support utilizing SMS as an adsorbent as a carbon capture, storage and utilization networking. Our insights into the physisorption-chemisorption on SMS are timely and relevant to help manage the re-use of SMS, and thus bring the global mushroom industry closer to environmental sustainability and toward a lower carbon society and circular economy.

Optimization of cultivation techniques improves the agronomic behavior of Agaricus subrufescens.

New species of medicinal mushrooms have emerged over the past several decades, such as the Sun mushroom, Agaricus subrufescens. Horticultural improvements are required to shift its cultivation from small-scale local production to large-scale international production. The research reported here evaluated the agronomic behavior and the chemical characteristics of the Sun mushroom as a function of i) nutritional supplementation ii) ruffling of the casing layer and iii) the temperature management on the primordia induction and reduction of the crop cycle. Supplementation was beneficial for yield, unit mushroom weigh and decrease in time to first harvest. Supplementation improved biological efficiency with Champfood providing a yield increase of 15% over the non-supplemented compost. Among the supplements only Promycel increased the individual mushroom weight. Ruffling overall improved the yield in the 2nd and 4th flush. Already biological efficiency was greater by 21%. The highest yield harvested in any single day in the crop occurred in 3rd flush with the amount of 2.484 kg of mushrooms per m2 for the rapid induction method. Still the biological efficiency was not significantly affected by the mushroom induction temperature method. Only the fat content of the mushrooms was positively affected by the rapid induction of primordia. Champfood supplement promotes a reduction in the value of earliness and an increase of 1st flush yield. The ruffling technique provided an increase in biological efficiency due to the great number of mushrooms harvested. Rapid primordia induction allowed the crop cycle to end 3 days earlier than the slow primordia induction, providing a higher production rate.

Use of peanut waste for oyster mushroom substrate supplementation-oyster mushroom and peanut waste.

The aim of the research was to verify the influence of macro and micronutrients present in the peanut waste (hulls and nuts) for supplementation of Pleurotus ostreatus substrate. The raw materials for base substrate preparation were Brachiaria dictyoneura, sugarcane bagasse (bulk material), rice and wheat bran, calcitic limestone, and gypsum. The following supplement formulations were used as treatments: (1) 100% peanut hulls, (2) 80% peanut hulls + 20% nuts, (3) 60% peanut hulls + 40% nuts, (4) 40% peanut hulls + 60% nuts, (5) 20% peanut hulls + 80% nuts, and (6) 100% nuts. A commercial supplement was also used as an additional treatment. The supplementation was done at spawning using the rates of 1% and 2% wet weight of the substrate. Positive correlations amongst yield and N content, and weight of mushroom and P and K content were verified with 1% supplement. A positive correlation between yield and Cu content, and a negative correlation between yield and Mn content were observed with 2% supplement. The use of peanut waste can be used as supplement for the production of P. ostreatus increasing biological efficiency up to 61%. A better combination can be reached with 20% peanut hulls + 80% nuts or 100% nuts. The addition of 2% supplement in the substrate provided greater yield than 1%.

First study of hormesis effect on mushroom cultivation.

The use of fungicides is common in mushroom cultivation, but no study was carried out applying reduced doses of fungicides in order to increase yield, taking account the hormesis effect. The aim of this manuscript was to verify the effects of different concentrations of fungicides to stimulate the productivity of different strains of Agaricus bisporus. Two stages were developed, an in vitro study to define the best concentration to be applied in the second experiment an agronomic study, which consisted of the application of the selected fungicides, in their respective concentrations, in an experiment carried out in the mushroom chamber. Clearly, the result of the hormesis effect on mushroom cultivation can be verified. The results obtained in the 1st stage of the study (in vitro) were not always reproduced in the 2nd stage of the study (in vivo). The kresoxim methyl active ingredient may be an important chemical agent, while strain ABI 15/01 may be an extremely important biological agent to increase yield in the study of hormesis effects.

Microbial additives in the composting process / Aditivos microbianos no processo de compostagem

ABSTRACT Composting is the process of natural degradation of organic matter carried out by environmental microorganisms whose metabolic activities cause the mineralization and partial humification of substances in the pile. This compost can be beneficially applied to the soil as organic fertilizer in horticulture and agriculture. The number of studies involving microbial inoculants has been growing, and they aim to improve processes such as composting. However, the behavior of these inoculants and other microorganisms during the composting process have not yet been described. In this context, this work aimed to investigate the effects of using a microbial inoculum that can improve the composting process and to follow the bacterial population dynamics throughout the process using the high-resolution melt (HRM) technique. To do so, we analysed four compost piles inoculated with Bacillus cereus, Bacillus megaterium, B. cereus + B. megaterium and a control with no inoculum. The analyses were carried out using samples collected at different stages of the process (5th to 110th days). The results showed that the bacterial inocula influenced the process of composting, altering the breakdown of cellulose and hemicelluloses and causing alterations to the temperature and nitrogen levels throughout the composting process. The use of a universal primer (rDNA 16S) allowed to follow the microbial succession during the process. However, the design of a specific primer is necessary to follow the inoculum throughout the composting process with more accuracy.

RESUMO A compostagem é um processo de degradação natural da matéria orgânica realizado por microrganismos presentes no ambiente, levando a mineralização e humificação parcial das substâncias presentes na pilha, esse composto formado pode ser beneficamente aplicado ao solo como fertilizante orgânico na horticultura e agricultura. O número de estudos envolvendo inoculantes microbianos é crescente, os quais tem por objetivo a otimização de processos de compostagem. Contudo, o comportamento desses inoculantes e da microbiota ao longo do processo não tem sido caracterizado. Nesse contexto, este trabalho foi realizado com o objetivo de avaliar o efeito da utilização de um inóculo bacteriano que promova melhorias no processo de compostagem, bem como o de acompanhar a dinâmica populacional bacteriana ao longo de todo o processo através da técnica de High Resolution Melt (HRM). Para isso foram analisados quatro pilhas de compostagem inoculadas com Bacillus cereus, Bacillus megaterium, B. cereus + B. megaterium e o controle sem adição de inóculo. Foram realizadas análises químicas e moleculares (HRM) das amostras coletadas em diferentes períodos da compostagem (5º ao 110º dias). Os resultados mostraram que os inóculos bacterianos influenciaram no processo de compostagem com alteração na degradação de celulose, hemicelulose bem como alteração da temperatura e níveis de nitrogênio ao longo da compostagem. A utilização de um primer universal (rDNA 16S) permitiu acompanhar a sucessão bacteriana ao longo do processo, nos tratamentos. Contudo a construção de um primer específico é necessário para acompanhar de maneira mais precisa o inóculo durante o desenvolvimento da compostagem.

Essential oils in the control of dry bubble disease in white button mushroom / Óleos essenciais no controle da doença bolha seca em champignon

ABSTRACT: Lecanicillium fungicola, which causes Dry bubble disease, induces infections and inflicts major losses in champignon production. The control can be managed through measures of hygiene and use of fungicides; however, in Brazil there are no registered products. This study aimed to estimate the influence of various essential oils extracted from Melissa officinalis, Thymus vulgaris, Origanum vulgare, Eucalyptus globulus, Cinnamomum zeylanicum and Syzygium aromaticum on the in vitro development and their uses. Therefore, analysis was performed of the L. fungicola isolates in vitro and the best oils were tested in vivo. Besides, the Agaricus bisporus - L. fungicola interaction was confirmed by scanning electron microscopy (SEM). Cinnamon and clove oils in concentrations of 0.4% and thyme oil of 0.8% were identified as good growth inhibitors of the pathogenic mycelium. Effective inhibition of the conidial germination was seen in all concentrations by cinnamon oil, and by clove and thyme oils only at 0.4% and 0.8%, respectively. When the essential oils were applied post-infestation in the in vivo experiments the incidence of the disease in the mushrooms was much lower. From the SEM it was clear that 19 hours after the inoculation of A. bisporus with L. fungicola, the spores had already completely germinated, revealing the presence of the infection. Therefore, the findings of this study indicated that the oil extracts of cinnamon, clove and thyme are potential and efficient alternatives in the control of dry bubble disease.

RESUMO: A doença bolha seca, causada pelo fungo Lecanicillium fungicola, provoca infecções graves que resultam em perdas significativas na produção de champignon. O controle se dá através de práticas sanitárias e do uso de fungicidas, porém no Brasil não há produtos registrados. Desta forma, este estudo objetivou avaliar o efeito de óleos essenciais extraídos de Melissa officinalis, Thymus vulgaris, Origanum vulgare, Eucalyptus globulus, Cinnamomum zeylanicum e Syzygium aromaticum sobre o desenvolvimento in vitro de isolados de L. fungicola e aplicação dos melhores óleos em teste in vivo. Além disso, a interação entre Agaricus bisporus e L. fungicola foi verificada por meio de microscopia eletrônica de varredura (MEV). Os óleos de canela e cravo a partir da concentração 0.4% e tomilho a 0.8% inibiram o crescimento micelial do patógeno. Já a germinação de conídios foi inibida pelo óleo de canela em todas as concentrações, bem como pelos óleos de cravo e tomilho, a 0.4% e 0.8%, respectivamente. No experimento in vivo, a aplicação dos óleos essenciais pós-infestação apresentou menor incidência da doença nos cogumelos produzidos. A MEV revelou que após 19 horas da inoculação de L. fungicola em A. bisporus, os esporos já estavam completamente germinados, o que indicava a ocorrência da infecção. Assim, os resultados deste trabalho sugerem que os óleos de canela, cravo e tomilho são alternativas potenciais para o controle da doença bolha seca.

Selection of strains for shiitake production in axenic substrate.

Shiitake mushroom consumption is increasing in Brazil. In addition to the implementation of new production methods, it is also important to increase productivity, quality and reduce production costs. In this study, six commercial Lentinula edodes strains were characterized for genetic diversity (rep-PCR analysis) and mushroom production (yield, number and weight of individual mushrooms) using different substrates and cultural conditions. All strains showed genetic differences by repetitive element palindromic based-polymerase chain reaction (rep-PCR). The richest substrate resulted in the greatest production under both environmental conditions. Strains LE4 and LE6 produced the majority of their mushrooms earlier than the other strains. The highest number of mushrooms was observed in the LE6 strain while the highest weights of individual mushrooms were observed in the LE4 strain. Controlled environmental conditions resulted in superior production for all strains, except for LE4, which had empirically greater yield in the semi-controlled environmental condition.

The Genetic Linkage Map of the Medicinal Mushroom Agaricus subrufescens Reveals Highly Conserved Macrosynteny with the Congeneric Species Agaricus bisporus.

Comparative linkage mapping can rapidly facilitate the transfer of genetic information from model species to orphan species. This macrosynteny analysis approach has been extensively used in plant species, but few example are available in fungi, and even fewer in mushroom crop species. Among the latter, the Agaricus genus comprises the most cultivable or potentially cultivable species. Agaricus bisporus, the button mushroom, is the model for edible and cultivable mushrooms. We have developed the first genetic linkage map for the basidiomycete A. subrufescens, an emerging mushroom crop known for its therapeutic properties and potential medicinal applications. The map includes 202 markers distributed over 16 linkage groups (LG), and covers a total length of 1701 cM, with an average marker spacing of 8.2 cM. Using 96 homologous loci, we also demonstrated the high level of macrosynteny with the genome of A. bisporus The 13 main LG of A. subrufescens were syntenic to the 13 A. bisporus chromosomes. A disrupted synteny was observed for the three remaining A. subrufescens LG. Electronic mapping of a collection of A. subrufescens expressed sequence tags on A. bisporus genome showed that the homologous loci were evenly spread, with the exception of a few local hot or cold spots of homology. Our results were discussed in the light of Agaricus species evolution process. The map provides a framework for future genetic or genomic studies of the medicinal mushroom A. subrufescens.

Influence of productivity and processing method on physicochemical characteristics of white button mushrooms in Brazil.

BACKGROUND: The white button mushroom is the edible fungus most commonly cultivated and commercialized in Brazil and worldwide. This work assesses the productivity of the different strains ABI 07/06 and ABI 06/05 of Agaricus bisporus grown under the conditions normally employed by growers in the southeast of Brazil, and the influence of four different chemical conservation methods on the physicochemical characteristics and storage properties of the fruit bodies. RESULTS: The productivities of strains ABI 07/06 and ABI 06/05 of white button mushrooms were found to be comparable. The colorimetric characteristics and chemical compositions (fat, fiber and protein contents) of the mushroom strains were similar, and these parameters were not influenced significantly by the conservation processes. Texture was negatively affected by all processing methods employed. CONCLUSION: It was concluded that chemical methods of processing mushrooms were not fully effective and novel alternative technologies should be considered by mushroom processors in Brazil. Some methods of mushroom storage using chemicals such as sodium metabisulfite are harmful to the human organism, so processing using autoclaving may be the best form of conservation of canned mushrooms.

Performance and meat quality of broiler chickens that are fed diets supplemented with Agaricus brasiliensis mushrooms.

This trial was performed to study the use of the mushroom Agaricus brasiliensis as an alternative additive to antimicrobial growth promoters in broiler chicken diets and to assess the quality of the broiler chicken breast meat of birds that are fed diets containing this fungus. Thus, 595 1-day-old chicks were reared in reused poultry litter without anticoccidial and antimicrobial additives. The results showed that a concentration of 1.6 g mushrooms/kg diet was ideal for these birds because it provided better bird performance. When the birds' immune system organs were analyzed, it was found that the addition of both mushrooms influenced the immune system organs of these broiler chickens. Adding A. brasiliensis to broiler chicken diets did not compromise breast meat quality.

Analysis of thermophilic fungal populations during phase II of composting for the cultivation of Agaricus subrufescens.

The composition and genetic diversity of fungal populations during phase II of compost production for the cultivation of Agaricus subrufescens was determined using culture-dependent and -independent methods on days 3, 6, 10, 12, and 14 of phase II composting. The isolates were morphologically characterized and subsequently analyzed using repetitive extragenic palindromic sequences (rep-PCR), and the intergenic region was sequenced to genetically identify the isolates. Changes on in the filamentous fungi population were analyzed using denaturing gradient gel electrophoresis (DGGE), and the resulting bands were sequenced. The population did not significantly change from day 3 to 10 (2.55 x 10(5) -6 x 10(5) CFU g(-1)), and maximum counts on day 14 of phase II composting (6.92 log CFU g(-1)). In the morphological characterization, Scytalidium thermophilum, Thermomyces lanuginosus, and Thermomyces ibadanensis were the most abundant identified species. The 26 most abundant isolates identified by morphological analysis were characterized using rep-PCR. A significant amount of genetic diversity was detected among the isolates of all three studied species. Based on the DGGE analysis, the diversity of the fungi was reduced during phase II composting, and S. thermophilum was the predominant species identified throughout the entire process. Thus, this study presents the first report of the involvement of T. ibadanensis in the production of compost for Agaricus mushroom cultivation.

Cultivo do champignon em função da temperatura / Buton mushroom cultivation in function of temperature

O cogumelo Agaricus bisporus é um cogumelo de clima temperado que requer baixa temperatura para a indução da frutificação. Essa exigência limita o seu cultivo no Brasil nos meses mais frios do ano ou exige a utilização de ambiente controlado, onerando muito a produção. Por isso, este trabalho teve como objetivo avaliar a produtividade de diferentes linhagens em função da temperatura de cultivo após a indução da frutificação. Diferentes linhagens de A. bisporus foram avaliadas quanto ao efeito da temperatura sobre a colonização do composto e a produtividade do cogumelo. As temperaturas de 21 e 25°C foram utilizadas durante a colonização do composto e, após a indução da frutificação, durante o ciclo de cultivo. Para todas as linhagens testadas, a temperatura de 25°C proporcionou maior velocidade de colonização do composto, favorecendo ciclos de cultivo mais curtos. Além disso, após a indução da frutificação a 18°C, a manutenção do ambiente de cultivo a 25°C proporcionou maior produtividade, quando comparada ao cultivo a 21°C. Para a linhagem mais produtiva, os três primeiros fluxos foram responsáveis por mais de 50% da produção total. Portanto, para um cultivo comercial em que é necessário manter volumes constantes de produção, os ciclos de cultivo poderiam ser limitados a três fluxos de produção.

The Agaricus bisporus is a button mushroom that requires low temperature to induce fruiting. This requirement limits our cultivation in Brazil during the coldest months of the year and requires the use of controlled environment. Therefore, this study aimed to assess the productivity of different strains depending on the growth temperature after induction of fruiting. A. bisporus strains were evaluated for the effect of temperature on the colonization of compost and mushroom productivity. Temperatures of 21 and 25°C were used for the substrate colonization and after induction of fruiting crop cycle. For all strains tested, temperature 25°C gave a quickly colonization of the compound, favoring shorter production cycles. Furthermore, after induction of fruiting at 18°C, maintaining the culture environment at 25°C gave a higher productivity to contrast with culture at 21°C. For the most productive strain, the first three streams were responsible for over 50% of total production. Thus, for a cash crop where it is necessary to maintain constant volumes of production, crop cycles could be limited to three productions flows.

Effect of cultivation practices on the ß-glucan content of Agaricus subrufescens basidiocarps.

The present work aimed to assess the effect of the following treatments on the medicinal potential (ß-glucan content) and agronomical performance (yield) of Agaricus subrufescens: five different fungal strains, three cultivation substrates (compost), four casing layers, and four cultivation environments. Two experiments were performed, and the results indicate that the greatest contribution to the variation in ß-glucan content was the strain (35.8%), followed by the casing layer (34.5%), the cultivation environment (15.7%), and the type of compost (9.9%). On the other hand the variation in yield was affected most by the cultivation environment (82.1%), followed by the strain (81.3%), casing layer (49.1%), and compost type (15.2%). These findings underscore the importance of developing a production protocol that employs specific cultivation practices for improving mushroom yield as well as ß-glucan content.

Physiologic response of Agaricus subrufescens using different casing materials and practices applied in the cultivation of Agaricus bisporus.

Casing materials and practices used in the cultivation of Agaricus bisporus were evaluated in the cultivation of Agaricus subrufescens, using the best techniques for optimization of production, including the possibility of re-casing of the compost for the production of a second crop of mushroom. Casing based on peat moss, loam soil or coir was compared to casing material mixed with or without spawn-run compost. Based on the results, we conclude that the casing layer used in the cultivation of A. subrufescens should not necessarily be the same as that used in the cultivation of A. bisporus. For the tested strain cultivated with loam soil as casing layer, the ruffling technique is highly superior to CACing and should be pursued in further research. The re-casing of compost in new cycles showed good results suggesting that the currently used compost could be improved.

Application of Hazard Analysis and Critical Control Points (HACCP) to the Cultivation Line of Mushroom and Other Cultivated Edible Fungi.

The Hazard analysis and critical control points (HACCP) is a preventive system which seeks to ensure food safety and security. It allows product protection and correction of errors, improves the costs derived from quality defects and reduces the final overcontrol. In this paper, the system is applied to the line of cultivation of mushrooms and other edible cultivated fungi. From all stages of the process, only the reception of covering materials (stage 1) and compost (stage 3), the pre-fruiting and induction (step 6) and the harvest (stage 7) have been considered as critical control point (CCP). The main hazards found were the presence of unauthorized phytosanitary products or above the permitted dose (stages 6 and 7), and the presence of pathogenic bacteria (stages 1 and 3) and/or heavy metals (stage 3). The implementation of this knowledge will allow the self-control of their productions based on the system HACCP to any plant dedicated to mushroom or other edible fungi cultivation.

Electron microscopy studies of basidiosporogenesis in Agaricus brasiliensis.

The objective of this work was to study the basidiosporogenesis and the intraspecific variation in the number of basidiospores produced per basidium in Agaricus brasiliensis with transmission (TEM) and scanning electron microscopy (SEM). A. brasiliensis produces predominantly tetrasporic basidia, but this trait may vary depending on the strain. For certain strains, such as CS2 and CS7, the frequency of bisporic and trisporic basidia was similar to, or greater than, that of tetrasporic strains. These results suggest that some strains of A. brasiliensis may be amphithallic; however, this behavior is variable and strain dependent. The development of basidia and basidiospores occurs asynchronously during basidiocarp production. The basidiospore cell wall is composed of three distinct layers and presents variable thickness. The conspicuous presence of lipid bodies also was observed in the basidiospores, while nuclei, mitochondria, vacuoles and dolipore septa could be visualized only in the basidia. The basidiospores generally are produced free but also may be enveloped by an extracellular matrix with unknown chemical composition. The presence of connection hyphae linking the basidia was observed for the first time in A. brasiliensis. This characteristic, so far not reported for other fungi, may represent a specific strategy of A. brasiliensis for exchanging nuclei and other cell material between basidial cells during basidiosporogenesis.