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

Influence of nitrogen sources on the enzymatic activity and grown by Lentinula edodes in biomass Eucalyptus benthamii / Influência das fontes de nitrogênio na atividade enzimática e crescimento de Lentinula edodes na biomassa Eucalyptus benthamii

Abstract Lignocellulose is the most abundant environmental component and a renewable organic resource in soil. There are some filamentous fungi which developed the ability to break down and use cellulose, hemicellulose and lignin as an energy source. The objective of this research was to analyze the effect of three nitrogen resources (ammonium sulfate, saltpetre, soybean) in the holocellulolitic activity of Lentinula edodes EF 50 using as substrate sawdust E. benthamii. An experimental design mixture was applied with repetition in the central point consisting of seven treatments (T) of equal concentrations of nitrogen in ammonium sulfate, potassium nitrate and soybean. The enzymatic activity of avicelase, carboxymetilcellulase, β-glucosidase, xylanases and manganese peroxidase was determined. The humidity, pH, water activity (aw) and qualitative analysis of mycelial growth in 8 times of cultivation were evaluated. The results showed negative effect on enzyme production in treatments with maximum concentration of ammonium sulfate and potassium nitrate. The treatments with cooked soybean flour expressed higher enzymatic activities in times of 3, 6 and 9 days of culture, except in the activity of manganese peroxidase. The highest production was observed in the treatment with ammonium sulfate, and soybean (83.86 UI.L–1) at 20 days of cultivation.

Resumo Lignocelulose é o componente mais abundante do meio ambiente e recurso orgânico renovável no solo. Alguns fungos filamentosos têm desenvolvido a habilidade de degradar e utilizar celulose, hemicelulose e lignina como fonte de energia. O objetivo deste trabalho foi analisar o efeito de três fontes de nitrogênio (sulfato de amônio, nitrato de potássio e farelo de soja) na atividade enzimática de Lentinula edodes EF 50 utilizando como substrato serragem de E. benthamii. Foi aplicado um planejamento experimental de mistura com três repetições no ponto central constituído de sete tratamentos (T) de iguais concentrações em nitrogênio de sulfato de amônia, nitrato de potássio e farinha de soja cozida. Foram determinadas a atividade enzimática da avicelase, carboximetilcelulase, β-glicosidase, xilanases e manganês peroxidase. Foram avaliados o teor de umidade, pH, atividade de água (aw) e análise qualitativa do crescimento micelial em 8 tempos de cultivo. Os resultados mostraram efeito negativo na produção das enzimas nos tratamentos com máxima concentração de sulfato de amônia e nitrato de potássio. Os tratamentos com farinha de soja cozida expressaram maiores atividades enzimáticas, nos tempos de 3, 6 e 9 dias de cultivo exceto na atividade do manganês peroxidase. A maior produção foi observada no tratamento com sulfato de amônia e farinha de soja cozida (83.86 UI.L–1) em 20 dias de cultivo.

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 CaS0(4), 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.

Isolation of a laccase with HIV-1 reverse transcriptase inhibitory activity from fresh fruiting bodies of the Lentinus edodes (Shiitake mushroom).

A laccase with a molecular mass of 67 kDa and inhibitory activity toward HIV-1 reverse transcriptase (IC50 = 7.5 M) was isolated from fresh fruiting bodies of the Lentinus edodes (Shiitake mushroom). Its characteristics were compared with those of laccases from cultured mushroom mycelia reported earlier. The laccase was unadsorbed on DEAE-cellulose, Affi-gel blue gel and CM-cellulose, but was adsorbed on Con A-Sepharose. About 50-fold purification was achieved with a 19.2% yield of the enzyme. The activity of the enzyme increased steadily from 20°C to 70°C. The activity disappeared after exposure to the boiling temperature for 10 min. Its optimal pH was 4 and very little enzyme activity remained at and above pH 10. The laccase inhibited HIV-1 reverse transcriptase with an IC50 of 7.5 M, but did not demonstrate any antifungal or anti-proliferative activity.

Quantitative changes in the biochemical composition of lignocellulosic residues during the vegetative growth of Lentinula edodes

The chemical changes in barley-straw (BS), wheat-straw (WS) and vineyard-pruning (VP) substrates were determined during colonization of Lentinula edodes mycelia (during primordium development) in solid state fermentation. Primordia appeared 39-50 days after inoculation. VP appeared to promote early sporophore initiation. The concentration of hemicellulose in BS and VP decreased gradually from 25.5 percent to 15.6 percent and from 15.8 percent to 12.3 percent, respectively. However in WS, hemicellulose decreased from 27.2 percent to 9.5 percent. Lignin broke down continuously in BS and WS, with 31.8 percent and 34.4 percent degradation, respectively; higher than that of cellulose. During the pinning stage, the C:N ratio decreased in VP and BS, but not in WS. On all substrates the phenols decreased notably throughout the first week of mycelial growth. The time elapsed (days) to pinning was positively correlated with cellulose content (r=0.89), total sugar (r=0.85) and inversely correlated to lignin (r=-1.00) and phenol content (r=-0.55).

Cinética micelial dos fungos comestíveis Pleurotus ostreatus e Lentinula edodes em resíduos lignocelulósicos / Mycelial kinetics of edible fungi Pleurotus ostreatus and Lentinula edodes in lignocellulosic residues

O objetivo do trabalho foi avaliar o crescimento micelial, em placa de Petri, de dois fungos comestíveis (Pleurotus ostreatus e Lentinula edodes) em seis meios de cultura [(malte-ágar, serragemdextrose-ágar-marupá (SDA-MA), serragem-dextrose-ágar-cajuí (SDA-CA), serragem-dextroseágar-açaí (SDA-AÇA), serragem-dextrose-ágar-banana 50% (BAN 50%) e serragem-dextroseágar-banana 100% (BAN 100%)]. O delineamento experimental foi inteiramente casualizado, em esquema fatorial 6 x 2. Cada tratamento constou de seis repetições, correspondente a uma placa de Petri, totalizando 72 unidades experimentais. Verificou-se que, em todos os meios à base de resíduos, o P. ostreatus apresentou um melhor desenvolvimento micelial (81,00; 64,66; 81,00; 50,16; e 33,33 mm, para SDA-MA, SDA-CA, SDA-AÇA, BAN 50% e BAN 100%, respectivamente) que o L. edodes (32,00; 31,66; 27,66; 37,33; e 21,83 mm, para SDA-MA, SDA-CA, SDA-AÇA, BAN 50% e BAN 100%, respectivamente). Também constatou-se que, para os L. edodes, não houve vantagem, em relação ao crescimento micelial, no uso de meios à base de resíduos comparado ao meio malteágar (testemunha), o qual obteve o melhor desempenho (62,17mm). Já para o P. ostreatus, os meios SDA-MA e SDA-AÇA apresentaram as maiores médias de crescimento (81 mm), o que representa um incremento de crescimento de 34% em relação ao meio testemunha (malte-ágar), cujo média de crescimento foi de 60,33mm. Assim, de uma forma geral, os resíduos testados indicam potencial de aproveitamento na fungicultura, especialmente para o cultivo de P. ostreatus.

The objective of this work was to evaluate the mycelial growth of 2 edible fungi (Pleurotus ostreatus and Lentinula edodes) in 6 culture media [(malt-agar, sawdustdextrose-agar-marupá (SDA-MA), sawdust-dextrose-agar-cajuí (SDA-CA), sawdust-dextrose-agaraçaí (SDA-AÇA), sawdust-dextrose-agar-banana 50% (BAN 50%) and sawdust-dextrose-agar-banana 100% (BAN 100%)], in Petri dishes. The experimental design was totally randomized, in a 6x2 factorial scheme. Each treatment consisted of six repetitions in 1 Petri dish, totaling 72 experimental units. It was verified that P. ostreatus presented better mycelial development (81.00; 64.66; 81.00; 50.16 and 33.33mm for SDA-MA, SDA-CA, SDA-AÇA, BAN 50% and BAN 100%, respectively) than L. edodes (32.00; 31.66; 27.66; 37.33 and 21.83mm for SDA-MA, SDA-CA, SDA-AÇA, BAN 50% and BAN 100%, respectively). It was also verified that there was no advantage for L. edodes in relation to mycelial growth, when media based on residues were used, compared to malt-agar medium (control), which obtained the best performance (62.17mm). As for P. ostreatus, SDA-MA and SDA-AÇA medium presented the highest growth averages (81 mm), representing a growth increase of 34% in relation to the control medium (malt-agar), whose growth average was 60.33mm. Thus, the residues tested present potential to be used in fungiculture, especially for the cultivation of P. ostreatus.