Silencing of the Laccase (lacc2) Gene from Pleurotus ostreatus Causes Important Effects on the Formation of Toxocyst-like Structures and Fruiting Body.

A wide variety of biological functions, including those involved in the morphogenesis process of basidiomycete fungi, have been attributed to laccase enzymes. In this work, RNA interference (RNAi) was used to evaluate the role of the laccase (lacc2) gene of Pleurotus ostreatus PoB. Previously, transformant strains of P. ostreatus were obtained and according to their level of silencing they were classified as light (T7), medium (T21) or severe (T26 and T27). The attenuation of the lacc2 gene in these transformants was determined by RT-PCR. Silencing of lacc2 resulted in a decrease in laccase activity between 30 and 55%, which depended on the level of laccase expression achieved. The silenced strains (T21, T26, and T27) displayed a delay in the development of mycelium on potato dextrose agar (PDA) medium, whereas in the cultures grown on wheat straw, we found that these strains were incapable of producing aerial mycelium, primordia, and fruiting bodies. Scanning electron microscopy (SEM) showed the presence of toxocyst-like structures. The highest abundance of these structures was observed in the wild-type (PoB) and T7 strains. However, the abundance of toxocysts decreased in the T21 and T26 strains, and in T27 they were not detected. These results suggest that the presence and abundance of toxocyst-like structures are directly related to the development of fruiting bodies. Furthermore, our data confirm that lacc2 is involved in the morphogenesis process of P. ostreatus.

Insight into the evolutionary and domesticated history of the most widely cultivated mushroom Agaricus bisporus via mitogenome sequences of 361 global strains.

Agaricus bisporus is the most widely cultivated edible mushroom in the world with a only around three hundred years known history of cultivation. Therefore, it represents an ideal organism not only to investigate the natural evolutionary history but also the understanding on the evolution going back to the early era of domestication. In this study, we generated the mitochondrial genome sequences of 352 A. bisporus strains and 9 strains from 4 closely related species around the world. The population mitogenomic study revealed all A. bisporus strains can be divided into seven clades, and all domesticated cultivars present only in two of those clades. The molecular dating analysis showed this species origin in Europe on 4.6 Ma and we proposed the main dispersal routes. The detailed mitogenome structure studies showed that the insertion of the plasmid-derived dpo gene caused a long fragment (MIR) inversion, and the distributions of the fragments of dpo gene were strictly in correspondence with these seven clades. Our studies also showed A. bisporus population contains 30 intron distribution patterns (IDPs), while all cultivars contain only two IDPs, which clearly exhibit intron loss compared to the others. Either the loss occurred before or after domestication, that could suggest that the change facilitates their adaptation to the cultivated environment.

Agaricus macrochlamys, a New Species from the (Sub)tropical Cloud Forests of North America and the Caribbean, and Agaricus fiardii, a New Synonym of Agaricus subrufescens.

Agaricus is a genus of fungi in the family Agaricaceae, with several highly priced edible and medicinal species. Here we describe Agaricus macrochlamys, a new species, in A. sect. Arvenses, sympatric and morphologically cryptic with the edible and medicinally cultivated mushroom, A. subrufescens. Phylogenetic analyses showed that A. macrochlamys is closely related to A. subrufescens, and that A. fiardii is a new synonym of A. subrufescens. Despite being morphologically cryptic, A. macrochlamys can be distinguished from A. subrufescens by several ITS and tef1α species-specific markers and a 4-bp insertion in the tef1α sequence. Furthermore, A. subrufescens is a cosmopolitan species, while A. macrochlamys distribution is so far restricted to Mexico, the Dominican Republic, and the United States.

Methanolic Extracts from Cultivated Mushrooms Affect the Production of Fumonisins B and Fusaric Acid by Fusarium verticillioides.

The maize pathogen Fusarium verticillioides and their mycotoxins cause damage to plants, animals, and human health. This work aimed to evaluate the effect of crude extracts (CEs) from Agaricus subrufescens, Lentinula edodes, and Pleurotus ostreatus fruiting bodies on in vitro production of biomass and mycotoxins by two strains of F. verticillioides. Stipes and pilei were separated before extraction for A. subrufescens and L. edodes. Comparative metabolomics and dereplication of phenolic compounds were used to analyze all CEs. Mushroom CEs did not significantly inhibit the production of mycelial biomass at concentrations of 2 mg mL⁻1. CEs from A. subrufescens (stipes and pilei) and L. edodes pilei inhibited the production of fumonisins B1 + B2 + B3 by 54% to 80%, whereas CE from P. ostreatus had no effect. In contrast, CE from L. edodes stipes dramatically increased the concentration of fumonisins in culture media. Fusaric acid concentration was decreased in cultures by all CEs except L. edodes stipes. Differences in phenolic composition of the extracts may explain the different effects of the CE treatments on the production of mycotoxins. The opposing activities of stipes and pilei from L. edodes offer an opportunity to search for active compounds to control the mycotoxin production by F. verticillioides.

Genetic characterization, evaluation of growth and production of biomass of strains from wild edible mushrooms of Lyophyllum of Central Mexico

Abstract The present study conducted a genetic characterization and determined growth rate and biomass production in solid and liquid media, using strains obtained from wild edible sporomes of Lyophyllum that grow in high mountains. Vegetative isolation was used to obtain a total of four strains, which were divided into two clades within the section Difformia: Lyophyllum sp. and Lyophyllum aff. shimeji. Growth rate and biomass production were influenced by both the culture media and the strains. In a potato dextrose agar medium, the strains presented a higher growth rate, while in a malt extract-peptone and yeast agar medium, the growth rate was lower, but with a higher biomass production that was equal to that in the malt extract-peptone and yeast liquid medium.

Genetic characterization, evaluation of growth and production of biomass of strains from wild edible mushrooms of Lyophyllum of Central Mexico.

The present study conducted a genetic characterization and determined growth rate and biomass production in solid and liquid media, using strains obtained from wild edible sporomes of Lyophyllum that grow in high mountains. Vegetative isolation was used to obtain a total of four strains, which were divided into two clades within the section Difformia: Lyophyllum sp. and Lyophyllum aff. shimeji. Growth rate and biomass production were influenced by both the culture media and the strains. In a potato dextrose agar medium, the strains presented a higher growth rate, while in a malt extract-peptone and yeast agar medium, the growth rate was lower, but with a higher biomass production that was equal to that in the malt extract-peptone and yeast liquid medium.

Hydrolytic enzyme activities in shiitake mushroom (Lentinula edodes) strains cultivated on coffee pulp.

Hydrolytic enzyme production (cellulases, laminarinases and xylanases) was studied in cultures of Lentinula edodes on sterilized coffee pulp. Samples of substrate colonized by mycelia were taken after 7, 14, 21, 28 and 35 days of incubation at 25°C (W1 to W5) and during the fruiting period at different stages: formation of primordia (PF), first harvest (H) and one week after the first harvest (PH). The enzymatic activity was lower during the early mycelial growth and showed higher levels during the formation and development of fruiting bodies. During the reproductive stage of the fungus, the samples were subjected to a soaking treatment; however, it was not possible to relate this soaking treatment to the increase in enzyme production. The levels of enzymatic activity suggest that secretion of the studied enzymes does not influence the adaptability of the strains to the substrate.

Actividad de las enzimas hidrolíticas en cepas del hongo shiitake (Lentinula edodes) cultivadas en pulpa de café / Hydrolytic enzyme activities in shiitake mushroom (Lentinula edodes) strains cultivated on coffee pulp

Se estudió la producción de enzimas hidrolíticas (celulasas, laminarinasas y xilanasas) en cultivos de Lentinula edodes en pulpa de café estéril. Se tomaron muestras de sustrato colonizado por el micelio después de 7, 14, 21, 28 y 35 días de incubación a 25°C (W1 a W5) y durante el período de fructificación en diferentes etapas: formación de primordios (PF), primera cosecha (H) y una semana después de la primera cosecha (PH). La actividad enzimática fue menor al inicio del crecimiento micelial y mostró mayores niveles en la formación y el desarrollo de basidiomas. Durante la etapa reproductiva del hongo, las muestras se sometieron a un tratamiento de remojo. Sin embargo, no fue posible relacionar este tratamiento con el aumento de la producción de enzimas. Los niveles de actividad enzimática sugieren que la secreción de las enzimas estudiadas no influye en la capacidad de adaptación de las cepas al sustrato

Hydrolytic enzyme production (cellulases, laminarinases and xylanases) was studied in cultures of Lentinula edodes on sterilized coffee pulp. Samples of substrate colonized by mycelia were taken after 7, 14, 21, 28 and 35 days of incubation at 25°C (W1 to W5) and during the fruiting period at different stages: formation of primordia (PF), first harvest (H) and one week after the first harvest (PH). The enzymatic activity was lower during the early mycelial growth and showed higher levels during the formation and development of fruiting bodies. During the reproductive stage of the fungus, the samples were subjected to a soaking treatment; however, it was not possible to relate this soaking treatment to the increase in enzyme production. The levels of enzymatic activity suggest that secretion of the studied enzymes does not influence the adaptability of the strains to the substrate

HS/GC-MS analyzed chemical composition of the aroma of fruiting bodies of two species of genus Lentinus (Higher Basidiomycetes).

The chemical composition of the aroma of fresh fruiting bodies of the cultivated mushroom Lentinus boryanus is described here and compared with medicinal shiitake mushroom L. edodes. Volatile compounds were analyzed through headspace sampling coupled with gas chromatography-mass spectrometry. The mushrooms under study were grown on different substrates based on barley straw, sugarcane bagasse, oak wood sawdust, and beech leaf litter. It was determined that L. boryanus as well as L. edodes contain an abundant amount of a volatile compound identified as 3-octanone with a sweet fruity aroma. On the other hand, only L. boryanus produced 3-octanol a characteristic aroma of cod liver oil. In total, 10 aromatic compounds were identified, some of which were obtained exclusively in one species or substrate.

Improvement of yield of the edible and medicinal mushroom Lentinula edodes on wheat straw by use of supplemented spawn.

The research evaluated the interactions of two main factors (strain / types of spawn) on various parameters with the purpose to assess its effect on yield and biochemical composition of Lentinula edodes fruiting bodies cultivated on pasteurized wheat straw. The evaluation was made with four strains (IE-40, IE-105, IE-124 and IE-256). Different types of spawns were prepared: Control (C) (millet seed, 100%), F1 (millet seed, 88.5%; wheat bran, 8.8%; peat moss, 1.3%; and CaS04, 1.3%) and F2 (the same formula as F1, but substituting the wheat bran with powdered wheat straw). Wheat straw was pasteurized by soaking it for 1 h in water heated to 65 °C. After this the substrate (2 kg wet weight) was placed in polypropylene bags. The bags were inoculated with each spawn (5% w/w) and incubated in a dark room at 25 °C. A proximate analysis of mature fruiting bodies was conducted. The mean Biological Efficiency (BE) varied between 66.0% (C-IE-256) and 320.1% (F1-IE-124), with an average per strain of 125.6%. The highest mean BE was observed on spawn F1 (188.3%), significantly different from C and F2. The protein content of fruiting bodies was high, particularly in strain IE-40-F1 (17.7%). The amount of fat varied from 1.1 (F1-IE-40) to 2.1% (F2-IE-105) on dry matter. Carbohydrates ranged from 58.8% (F1-IE-40) to 66.1% (F1-IE-256). The energy value determined ranged from 302.9 kcal (F1-IE-40) to 332.0 kcal (F1-IE-256). The variability on BE observed in this study was significantly influenced by the spawn's formulation and genetic factors of the different strains.

Cebadores para la amplificación del gen de la (1, 3)-Beta-glucano sintasa y caracterización parcial de la enzima en Ganoderma lucidum / Primers for (1, 3)-Beta-glucan synthase gene amplification and partial characterization of the enzyme in Ganoderma lucidum

Antecedentes. El β-(1,3)(1,6)-D-glucano es un compuesto de la pared celular de los hongos que presenta efectos inmunomoduladores y anticancerígenos. La (1,3)-β-glucano sintasa es una de las principales enzimas involucradas en su síntesis. Objetivos. Diseñar cebadores para amplificar y caracterizar parcialmente el gen correspondiente a la enzima (1,3)-β-glucano sintasa y probarlos en la cepa CP-132 de Ganoderma lucidum. Métodos. Los cebadores fueron diseñados realizando una búsqueda de la secuencia del gen en otros hongos. Después, con la técnica de PCR se probaron los cebadores utilizando ADN extraído de la cepa CP-382 de G. lucidum. Las secuencias obtenidas se compararon con aquellas de la base de datos del GenBank. Resultados. Se diseñaron 3 pares de cebadores. Todos los pares amplificaron productos de PCR de tamaño esperado. Las secuencias amplificadas con los pares BGS2113UmF y BGS3097UmR, y BGS547UmF y BGS2113UmR correspondieron a un par de secciones del gen de la (1,3)-β-glucano sintasa. Las secuencias deducidas de aminoácidos mostraron una similitud alta con genes homólogos de otros hongos, especialmente con aquellos de la clase Agaricomycetes. Conclusiones. El diseño de cebadores para amplificar parcialmente el gen de la (1,3)-β-glucano sintasa a partir de secuencias de genes homólogos fue exitoso. Estos cebadores permitirán en un futuro la caracterización de esta importante enzima en un amplio grupo de hongos (AU)

[Primers for (1,3)-ß-glucan synthase gene amplification and partial characterization of the enzyme in Ganoderma lucidum]. / Cebadores para la amplificación del gen de la (1,3)-ß-glucano sintasa y caracterización parcial de la enzima en Ganoderma lucidum.

BACKGROUND: ß-(1,3)(1,6)-D-glucan is fungal cell wall component that has demonstrated immunomodulatory and anti-cancer effects. The (1,3)-ß-glucan synthase is one of the main enzymes involved in its biosynthesis. AIMS: To design primers to partially amplify and characterize the (1,3)-ß-glucan synthase gene and to determine them in Ganoderma lucidum (G. Lucidum) strain CP-132. METHODS: The primers were designed on the basis of homologous genes in other fungi. Then, using the PCR technique, primers were tested using DNA extracted from the G. lucidum strain CP-382. Amplified sequences were compared with those from the GenBank. RESULTS: Three primer pairs were designed; all of them produced amplicons of the expected size. The sequences obtained with primer pairs BGS2113UmF and BGS3097UmR, and BGS547UmF and BGS2113UmR matched with 2 sections of the (1,3)-ß-glucan synthase gene. The deduced amino acid sequences showed high similarity with homologous genes from other fungi, particularly with those of the Agaricomycetes class. CONCLUSIONS: The primer design to partially amplify the (1,3)-ß-glucan synthase gene of G. lucidum using sequences from homologous genes was successful. These primers will allow to characterize this important enzyme in a wide group of fungi.

Preservation of Agaricus subrufescens strains at low temperature by using cultures on sorghum grains.

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.

Hongos comestibles y medicinales en Iberoamérica: investigación y desarrollo en un entorno multicultural / Edible and medicinal fungi in Ibero-America: research and development in a multicultural environment

Los macromicetos u hongos macroscópicos conforman un grupo especial del Reino de los Hongos que adquiere cada día mayor relevancia. En efecto, existe en el mundo un claro interés por el conocimiento y la domesticación de estos organismos, toda vez que se descubren cada día mayores posibilidades de beneficio para la humanidad a partir de ellos. Si de la totalidad de especies de hongos estimadas sobre la tierra, una cuarta parte pertenecen a este grupo (lo que hace una estimación de alrededor de 400 mil especies), es evidente que aún queda muchísimo por conocer. Los avances actuales de la humanidad han permitido cultivar sólo un centenar. Es claro entonces, que con 0.025% de estos organismos domesticados ­mas no todos ellos bien conocidos- la rama de la micotecnología dedicada al cultivo de los macromicetos aún no inicia su expansión, mas bien se encuentra en fase de latencia o incubación y se esperaría que abundantes descubrimientos y grandes desarrollos y beneficios se concretaran en un futuro no muy lejano, en base a investigación y se difundieran mediante capacitación, transferencia y apropiación del conocimiento. Los temas tratados durante el taller superaron el planteamiento inicial ya que, además de tratar estrictamente el tema de cultivo de hongos comestibles, se abordaron temas como la situación y el potencial de los hongos silvestres. También se trataron diferentes aspectos de varios hongos de interés medicinal y funcional, y aún temas sobre manejo postcosecha de los hongos, entre otros. Estos tópicos no estaban contemplados inicialmente, pero resultaron indispensables para conformar una mejor perspectiva sobre la situación que guarda el cultivo y el aprovechamiento de los macromicetos en Iberoamérica.

[Elevated liver enzymes, impaired fasting glucose and undiagnosed diabetes]. / Enzimas hepáticas elevadas, glucosa anormal de ayuno y diabetes no diagnosticada en medicina familiar.

BACKGROUND: emerging evidence suggests that elevated liver enzymatic activity is associated with diabetes. The purpose was to investigate the prevalence of elevated liver enzymes and its relationship between impaired fasting glucose (IFG) and undiagnosed diabetes in family medicine practice. METHODS: a cross-sectional prospective analytic study was conducted in a representative sample of 100 patients aged 25 to 60 years who underwent to a screening for diabetes. Risk factors, BMI, waist circumference, blood pressure, fasting glucose, lipid profile, alanine aminotransferase (ALT), aspartate aminotransferase (AST), gamma-glutamyltransferase (GGT) and C-reactive protein were evaluated. The relationships between liver enzymes, undiagnosed diabetes and IFG were analyzed through c(2) and Student's t test to identify differences in continuous variables. RESULTS: the prevalence found in undiagnosed diabetes were ALT 16.9 %, AST 15.8 % and GGT 20.6 % and in IFG were 76.3 %, 68.4 % and 77.8 % respectively. The relationships between elevated ALT (0.001) and GGT (0.000) with undiagnosed diabetes and IFG were statistically significant. CONCLUSION: elevated ALT or GGT raise the possibility of undiagnosed type 2 diabetes mellitus in family practice.

OBTENCIÓN DE ESCLEROCIOS DE MORILLA (Morchella esculenta) EN DIFERENTES MEDIOS DE CULTIVO / OBTAINING SCLEROTIA OF MOREL MUSHROM (Morchella esculenta) IN DIFFERENT CULTURE MEDIA / OBTENÇÃO DE ESCLERÓCIOS DE MORILLA (Morchella esculenta) EM DIFERENTES MEIOS DE CULTIVO

Morchella esculenta es un hongo comestible de alto valor comercial y la obtención de esclerocios es considerada como la clave para su cultivo. En este trabajo se evaluó el desarrollo de la cepa IE-750 en ocho medios de cultivo sólido y seis en forma líquida, utilizando como parámetros el crecimiento micelial, la producción de biomasa, la habilidad para producir esclerocios y su biomasa. El mejor crecimiento micelial se obtuvo en el tratamiento con composta (T7: 53,87cm²), y en cuanto a la biomasa, el medio de cultivo con levadura fue mejor (T3: 80,3mg). Los tratamientos con gallinaza y composta, presentaron 40 y 80% de esclerocios, respectivamente, tanto en medio sólido como líquido. La mayor cantidad de biomasa de estas estructuras se presentó en el tratamiento con composta en medio sólido (T7: 27,04mg). Los esclerocios se obtuvieron en lapsos de 9-12 días (medio sólido) y de 7-9 días (medio líquido), lo cual es un tiempo relativamente corto y abre una posibilidad de cumplir con una de las condiciones necesarias para su domesticación.

Morchella esculenta is an edible mushroom of high commercial value and obtaining sclerotia is considered important for its cultivation. In this work, the growth of the IE-750 strain was studied in eight solid and six liquid culture media. Parameters assessed were mycelial growth, production of biomass, and ability to produce sclerotia and their biomass. The best mycelial growth was obtained in the treatment containing compost extract (T7: 53.87cm²), while the highest production of biomass was recorded in the treatment containing yeast (T3: 80.3mg). Treatments with poultry manure and compost showed 40 and 80% of sclerotia in solid and liquid media, respectively, and the highest sclerotia biomass was recorded in the compost treatment (solid medium). Sclerotia were obtained in periods of 9-12 days (solid medium) and 7-9 days (liquid medium).

Morchella esculenta é um cogumelo comestível de alto valor comercial e a obtenção de esclerócios é considerada como a chave para seu cultivo. Neste trabalho foi avaliado o desenvolvimento da cepa IE-750 em oito meios de cultivo sólido e seis em forma líquida, utilizando como parâmetros o crescimento micelial, a produção de biomassa, a habilidade para produzir esclerócios e sua biomassa. O melhor crescimento micelial foi obtido no tratamento por compostagem (T7: 53,87cm²), e em relação à biomassa, o meio de cultivo com levedura foi melhor (T3: 80,3mg). Os tratamentos de cama-de-frango e compostagem apresentaram 40 e 80% de esclerócios, respectivamente, tanto no meio sólido como líquido. A maior quantidade de biomassa de estas estruturas se apresentou no tratamento com compostagem no meio sólido (T7: 27,04 mg). Os esclerócios foram obtidos em períodos de 9-12 dias (meio sólido) e de 7-9 dias (meio líquido), o qual é tempo relativamente curto e abre uma possibilidade de cumprir com uma das condições necessárias para sua domesticação.

Role of Bacillus spp. in antagonism between Pleurotus ostreatus and Trichoderma harzianum in heat-treated wheat-straw substrates.

This study aimed to identify bacteria involved in Trichodermaharzianum inhibition while promoting Pleurotus ostreatus defences in order to favour cultivation-substrate selectivity for mushroom production. PCR-DGGE profiles of total DNA from wheat-straw substrate showed weak differences between bacterial communities from substrate inoculated with P. ostreatus with or without T. harzianum. The major cultivable bacteria were isolated from three batches of wheat-straw-based cultivation substrates showing an efficient selectivity. They were screened for their ability to inhibit T.harzianum. By using specific media for bacterial isolation and by sequencing certain 16S-rDNA, we observed that Bacillus spp. were the main inhibitors. Among them, a dominant species was identified as Paenibacillus polymyxa. This species was co-cultivated on agar media with P. ostreatus. The measurement of laccase activities from culture plugs indicated that P. polymyxa induced increases in enzyme activities. Bacillus spp. and specifically P. polymyxa from cultivation substrates are implicated in their selectivity by both inhibiting the growth of T.harzianum and stimulating defences of the mushroom P. ostreatus through the induction of laccases. The management of microbial communities during P.ostreatus cultivation-substrate preparation in order to favour P. polymyxa and other Bacillus spp. growth, can be a way to optimize the development of P. ostreatus for mushroom production or other environmental uses of this fungus.

Interspecific interactions with Trichoderma longibrachiatum induce Pleurotus ostreatus defence reactions based on the production of laccase isozymes.

Laccases are phenoloxidases involved in aromatic compound transformation but also in stress response towards antagonist species such as Trichoderma sp. In this study intracellular isoforms of laccases produced by Pleurotus ostreatus in liquid cultures with or without Trichoderma longibrachiatum showed five isoforms with various intensities depending on the culture conditions suggesting a basal expression of these enzymes, which can be induced by interspecific interactions. A first attempt to analyse the induction of P. ostreatus laccase-gene expression by a biotic factor was realized using semi-quantitative RT-PCR. We showed that the transcription of a laccase gene of P. ostreatus can be modified by a biotic stress such as T. longibrachiatum.

Bioconversion of agrowastes by Lentinula edodes: the high potential of viticulture residues.

The production of four strains of edible mushroom Lentinula edodes was evaluated through solid-state fermentation (SSF) of vineyard pruning (VP), barley straw (BS), and wheat straw (WS). Biological efficiency, proximal composition, and energy value of the fruiting bodies, as well as substrate chemical changes after harvest, were determined. The shortest primordium formation time (28 days), highest biological efficiency (93.25%), highest yield (37.46%), and shortest production cycle (6 days) were observed in VP. The fruiting bodies obtained from VP had high energy value (379.09 to 392.95 kcal) and contents of protein (12.37 to 17.19%), but low contents of fat (1.82 to 2.15%). After SSF, phenol concentration decreased on VP (1.2 mmol/L) and BS (0.31 mmol/L), but on WS remained practically the same. Hemicellulose decreased in all substrates; cellulose increased on WS and decreased in the rest of the treatments. Lignin decreased on WS and BS, but its concentration increased on VP. The variability observed in the degradation capacity of lignocellulosic components was influenced by the substrate's nature, environmental factors, and genetic factors among strains. VP has great potential for shiitake production due to its low cost, short production cycles, and high biological efficiency.

Comparative culturing of Pleurotus spp. on coffee pulp and wheat straw: biomass production and substrate biodegradation.

The results of the cultivation of six strains of Pleurotus (P. djamor (2), P. ostreatus (2) and P. pulmonarius (2)) on coffee pulp and wheat straw are presented. Metabolic activity associated with biomass of each strain was determined, as well as changes in lignin and polysaccharides (cellulose and hemicellulose), phenolic and caffeine contents in substrate samples colonized for a period of up to 36 days. Analysis were made of changes during the mycelium incubation period (16 days) and throughout different stages of fructification. Greater metabolic activity was observed in the wheat straw samples, with a significant increase between 4 and 12 days of incubation. The degradation of polysaccharide compounds was associated with the fruiting stage, while the reduction in phenolic contents was detected in both substrates samples during the first eight days of incubation. A decrease was observed in caffeine content of the coffee pulp samples during fruiting stage, which could mean that some caffeine accumulates in the fruiting bodies.