Basidiomycetes are laccase producers used for hydrolysis of lignocellulosic byproducts in fermentative processes and could be used on biofuel production or ruminant feeding. The objective of this study was to evaluate the effect of concentrations of non-protein nitrogen sources on laccase production and mycelial growth of Pleurotus ostreatus, Lentinula edodes and Agaricus blazei. The fungi were grown on soybean hulls to which urea (U), ammonium sulfate (AS) or mixture of AS:U (1:1) were added to achieve carbon/nitrogen (C/N) ratios of 5, 15, 20 or 30. The average longitudinal mycelial growth was measured and laccase activity was determined by the oxidation of 2,2'-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid. Higher C/N ratios increased mycelial growth and decreased laccase production. The highest activities were obtained with a C/N ratio of 5. P. ostreatus, L. edodes and A. blazei produced more laccase when AS, AS:U and U, respectively, were added. In addition, C/N ratios lower than 30 induced laccase syntheses, inhibited mycelial growth and were a better condition for prehydrolysis of plant residues.

Alternative substrates for cryopreservation at -20°C have been little explored for basidiomycetes and could bring new possibilities of lower cost cryopreservation. Nevertheless, freezing temperatures between -15 and -60°C are very challenging because they frequently result in cryoinjuries. The objective of this study was to evaluate substrates associated to cryoprotective agents for Pleurotus ostreatus cryopreservation at -20 or -70°C in order to develop alternative techniques for basidiomycete cryopreservation. P. ostreatus was grown on potato dextrose agar or whole grains of oat, wheat, rice or millet and transferred to cryovials with cryoprotective solution with 1 % dimethyl sulfoxide, 5 % glycerol, 10 % saccharose, 4 % glucose, 6 % polyethylene glycol-6000 or 5 % malt extract. The mycelium in the cryovials were cryopreserved at -20 or -70°C and recovered for evaluation of the mycelial growth viability after 1 and 3 years. Both substrates and cryoprotectants affect the viability of the mycelial growth cryopreserved at -20 or -70°C; wheat grains combined with cryoprotectants such as saccharose or glucose are effective for keeping mycelium viable after cryopreservation at -20°C for 1 or 3 years; for cryopreservation at -70°C after 1 or 3 years, any substrate combined with any cryoprotectant is effective for preserving the mycelium viable, except for millet grains with polyethylene glycol after 3 years; semi-permeable cryoprotective agents such as saccharose and glucose are the most effective for cryopreservation at -20 or -70°C for at least 3 years.

The same substratum formulation to grow Agaricus bisporus has been used to grow Agaricus brasiliensis since its culture started in Brazil. Despite being different species, many of the same rules have been used for composting or axenic cultivation when it comes to nitrogen content and source in the substrate. The aim of this study was to verify the mycelial growth of A. brasiliensis in different ammonium sulfate and (or) urea concentrations added to cassava fiber and different carbon-to-nitrogen (C:N) ratios to increase the efficiency of axenic cultivation. Two nitrogen sources (urea and (or) ammonium sulfate) added to cassava fiber were tested for the in vitro mycelial growth in different C:N ratios (ranging from 2.5:l to 50:l) in the dark at 28 degrees C. The radial mycelial growth was measured after 8 days of growth and recorded photographically at the end of the experiment. Nitrogen from urea enhanced fungal growth better than ammonium sulfate or any mixture of nitrogen. The best C:N ratios for fungal growth were from 10:l to 50:l; C:N ratios below 10:l inhibited fungal growth.

ResumoPleurotus ostreatus é um produtor de biomassa e lacase, enzima utilizada em processos fermentativos para a hidrólise de substratos lignocelulósicos, com potencial de utilização na produção de biocombustíveis e na alimentação animal. Desta forma, há a necessidade de buscar substratos regionais mais apropriados para a produção de biomassa micelial e de lacase. Assim o objetivo deste trabalho foi avaliar o efeito das características físico-químicas de subprodutos da agroindústria na formulação de substratos para o crescimento micelial e a produção de lacase por P. ostreatus. O experimento foi realizado com as matérias-primas: fibra de soja, farelo de trigo, farelo de arroz, grãos de milho e sabugo de milho que foram separadas em função da granulometria e analisadas quanto à relação carbono/nitrogênio (C/N). O crescimento micelial foi avaliado em meio de cultivo sólido particulado em tubos cilíndricos de borosilicato. Em seguida a produção de lacase foi avaliada utilizando um planejamento fatorial fracionário 2 6-2 com as variáveis: granulometria do meio de cultivo e adição de minerais (cobre, zinco, ferro, cádmio e magnésio) no meio de cultivo. A produção de lacase foi determinada pela oxidação do ABTS (ácido 2,2'-azino-bis-(3-etilbenzotiazolina-6-sulfônico). Os resultados indicam que o fator mais importante para o crescimento micelial é a capacidade de retenção de oxigênio do meio de cultivo. Para o crescimento micelial de P. ostreatus o sabugo de milho e o farelo de trigo são os melhores componentes do substrato. As demais matérias-primas reduziram o crescimento micelial. Entretanto o fator mais importante para a indução da produção de lacase é a redução do tamanho da partícula, com aumento da área de contato entre o micélio e o substrato. Palavras-chave: Subprodutos agrícolas, micélio, substrato, lacase, Pleurotus ostreatus AbstractPleurotus ostreatus is a producer of biomass and laccase, an enzyme used in fermentation processes for the hydrolysis of lignocellulosic substrata, with potential use in biofuel production and animal feed. Thus, there is a need to seek more appropriate regional substrata for the production of mycelial biomass and laccase. Hence, the aim of this study was to evaluate the effect of physical and chemical characteristics of agro-industrial byproducts in a substratum formulation for the mycelial growth and laccase production

Objetivamos com esse artigo discutir as contradições presentes na proposta do Programa Mulheres Mil (PMM), voltado à proissionalização de nível básico das mulheres consideradas em situação de vulnerabilidade social. A institucionalização do PMM é uma estratégia de focalização da política pública no contexto de racionalização do Estado, ocasionando corte de gastos de políticas sociais que tenham viés universalizante. Trata-se de pesquisa bibliográica e documental, cuja análise enfatiza as dimensões contraditórias da proposta de formação proissional no PMM com base no contexto de reforma da educação proissional desde 1990. Dentre os aspectos do PMMevidenciados estão: a) não articulação com a ampliação dos níveis da escolaridade; b) atividades formativas pautadas no trabalho simples e não relacionadas aos avanços tecnológicos; e c) a inserção em setores precarizados do mundo do trabalho.