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.

Undergraduate dental sudents' perspectives about experiences in primary care for their education in the field of health / Perspectivas de graduandos em odontologia acerca das experiências na atenção básica para sua formação em saúde

Supervised training periods in primary care have been used as spaces for teaching and extension in the area of health, making it feasible to include undergraduates in concrete teaching-learning scenarios. The aim of this study was to analyze the perceptions of dental students about the importance of supervised training periods in Family Health Units to their professional education. The sample consisted of 185 students who answered the question: What is your opinion about the importance of this training period in SUS to your professional education? Comment on this experience and its positive and negative aspects The responses were analyzed by the quali-quantitative Collective Subject Discourse (CSD) technique. The students appreciated learning through practice in the service; contact with professionals from other areas; opportunity for technical-operative improvement and demonstrated sensitivity in the face of social reality, although they appeared to be concerned about being absent from the faculty, arguing that they were being prejudiced as regards their intramural clinical productivity, exhaustively demanded of them. It was concluded that students placed value on the extramural experience, however, it was perceived that there was still a predominant influence of focus on intramural clinical training.

Os estágios supervisionados na atenção básica vêm sendo utilizados como espaços de ensino e extensão nas áreas da saúde, viabilizando a inserção dos graduandos em cenários concretos de ensino-aprendizagem. O objetivo deste estudo foi analisar as percepções de acadêmicos de odontologia sobre a importância do estágio supervisionado em Unidades de Saúde da Família, para sua formação profissional. A amostra foi constituída por 184 acadêmicos que responderam à questão: Qual a sua opinião em relação à importância deste estágio no SUS para a sua formação profissional? Comente esta experiência e seus aspectos positivos e negativos. As respostas foram analisadas através da técnica qualiquantitativa do discurso do sujeito coletivo. Os alunos valorizaram o aprendizado através da prática no serviço, do contato com profissionais de outras áreas, da oportunidade de aperfeiçoamento técnico-operatório e demonstraram sensibilização frente à realidade social, embora tenham aparentado incômodo por se ausentarem da faculdade, sob o argumento de serem prejudicados quanto à produtividade da clínica intramuros, exaustivamente cobrada. Concluiu-se que os alunos valorizaram a experiência extramural, entretanto, percebeu-se que ainda há uma hegemonia do foco no treinamento clínico intramuros.

Evaluation of hollocelulase production by Lentinula edodes (Berk.) Pegler during the submerged fermentation growth using RSM / Avaliação da produção de enzimas holocelulolíticas por Lentinula edodes (Berk.) Pegler durante o crescimento em fermentação submersa usando MSR

The cellulase proteins have a great importance in the enzymatic hydrolysis of woody biomass. Despite of costs being a major concern, it has been a stimulus to study basidiomycetes biochemical properties which degrade lignocellulosic material and have prompted the processes' study for obtaining cellulolytic enzymes in fungi. The objective of this research was to evaluate the effects of the initial nitrogen content on (ammonium sulfate) and on sugar cane bagasse, which hereby, acts as an inducer of hydrolytic enzymes to produce cellulases and xylanases, using three Lentinula edodes (Berk.) Pegler strains as a transformation agent. A factorial design with 22 replications in the central point was conducted, varying concentrations of ammonium sulfate and sugar cane bagasse. The submerged cultures carried out in synthetic culture medium and incubated at 25°C for 7 days on an orbital shaker at 150 rpm. The total protein and cellulase activity as endoglucanase, exoglucanase and β-glucosidase and the xylanase was also determined. The results showed that the production of hydrolytic enzymes was stimulated by the presence of high concentrations of sugar cane bagasse (30g/L), characterizing it as an inducer due to the demonstrated proportional relationship. Thus, ammonium sulfate acted as a reducing agent in the synthesis of enzymes, being the low concentrations (0.1g/L) indicated for the enzyme production system under study. Among the studied strains, the EF52 showed higher activity for xylanase, endoglucanases, β-glucosidase and also protein.

As celulases são proteínas de grande importância na hidrólise enzimática de biomassa florestal. No entanto, seu custo elevado tem estimulado o estudo de processos de obtenção de enzimas celulolíticas por fungos filamentosos, tais como os basidiomicetos que apresentam propriedades bioquímicas para degradação de material lignocelulósico. O objetivo deste trabalho foi avaliar os efeitos do teor inicial de nitrogênio (sulfato de amônia) e de um indutor de enzimas hidrolíticas (bagaço de cana de açúcar) na produção de xilanases e celulases utilizando três isolados de Lentinula edodes (Berk.) Pegler como agente de transformação. Foi realizado um planejamento fatorial 22 com repetição no ponto central, variando as concentrações de sulfato de amônia e bagaço de cana de açúcar. O cultivo submerso realizado em meio de cultivo sintético e incubado a 25°C por 7 dias em agitador orbital a 150 rpm. Foram determinados o teor de proteínas totais e a atividade de celulase como: endoglucanase, exoglucanase e β-glucosidase e ainda xilanase. Os resultados demonstraram que a produção das enzimas hidrolíticas foi estimulada pela presença de alta concentração de bagaço de cana (30g/L), caracterizando-o como agente indutor devido à relação de proporcionalidade demonstrada. Por sua vez, o sulfato de amônio atuou como redutor da síntese de enzimas, sendo as baixas concentrações (0,1g/L) indicadas para o sistema de produção das enzimas em estudo. Quanto às linhagens, a EF52 mostrou maior atividade para xilanase, endoglucanases, β-glucosidase e proteínas.

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.