Multi-enzyme complex of white rot fungi in saccharification of lignocellulosic material

ABSTRACT The multi-enzyme complex (crude extract) of white rot fungi Pleurotus ostreatus, Pleurotus eryngii, Trametes versicolor, Pycnosporus sanguineus and Phanerochaete chrysosporium were characterized, evaluated in the hydrolysis of pretreated pulps of sorghum straw and compared efficiency with commercial enzyme. Most fungi complexes had better hydrolysis rates compared with purified commercial enzyme.

Lignocellulolytic enzyme production of Pleurotus ostreatus growth in agroindustrial wastes

The mushroom Pleurotus ostreatus has nutritional and medicinal characteristics that depend on the growth substrate. In nature, this fungus grows on dead wood, but it can be artificially cultivated on agricultural wastes (coffee husks, eucalyptus sawdust, corncobs and sugar cane bagasse). The degradation of agricultural wastes involves some enzyme complexes made up of oxidative (laccase, manganese peroxidase and lignin peroxidase) and hydrolytic enzymes (cellulases, xylanases and tanases). Understanding how these enzymes work will help to improve the productivity of mushroom cultures and decrease the potential pollution that can be caused by inadequate discharge of the agroindustrial residues. The objective of this work was to assess the activity of the lignocellulolytic enzymes produced by two P. ostreatus strains (PLO 2 and PLO 6). These strains were used to inoculate samples of coffee husks, eucalyptus sawdust or eucalyptus bark add with or without 20 % rice bran. Every five days after substrate inoculation, the enzyme activity and soluble protein concentration were evaluated. The maximum activity of oxidative enzymes was observed at day 10 after inoculation, and the activity of the hydrolytic enzymes increased during the entire period of the experiment. The results show that substrate composition and colonization time influenced the activity of the lignocellulolytic enzymes.

Thermostability of xylanolytic enzymes produced by Lentinula edodes UFV70

Xylanolytic enzymes produced by Lentinula edodes UFV70, cultivated in eucalyptus sawdust/rice bran medium, were stable at 50, 60 and 65ºC for 21 hours, losing only 15-25% activity. Fungus incubation at 50ºC for 12 hours and at 65ºC for 24 hours increased the amount of xylose produced.

Antimicrobial activity and mineral composition of shiitake mushrooms cultivated on agricultural waste

The antimicrobial activity and mineral composition of shiitake mushrooms were evaluated in four isolates of Lentinula edodes. Mushrooms were cultivated on artificial logs, based on eucalyptus sawdust enriched with 20 percent rice, wheat, or soybean bran, or combination of 10 percent of two of these supplements. The substrates were humidified with a 0.1 percent mate tea extract or water. Logs of Eucalyptus grandis were also used to cultivate the shiitake mushrooms. The antimicrobial activity of an aqueous extract, corresponding to 40 mg of mushroom dry matter, was in some cases, depending on the isolate, able to inhibit both Bacillus subtilis and Escherichia coli K-12, independent of substrate composition or the growth stage of the mushrooms. Nitrogen, phosphorus, potassium, magnesium and calcium concentrations varied according to the substrate on which the mushrooms were cultivated, being, generally, higher with cultivation on artificial rather than natural eucalyptus logs. It could be concluded that, in addition to the fungal isolate, substrate composition and, processing methods must be considered during the production of antimicrobial substance(s) as well as in the mushroom nutritional composition.

Production and regeneration of protoplasts from orchid Mycorrhizal Fungi Epulorhiza repens and Ceratorhiza sp

The aim of this work was to study the standardization of conditions to obtain and regenerate Epulorhiza repens and Ceratorhiza sp. protoplasts. For E. repens, the largest number of protoplasts (8.0 × 10(6) protoplasts/mL) was obtained in 0.6 M KCl, using 15 mg/mL of Lysing Enzymes, and 2-day-old fungal mycelium. When 0.5 M sucrose was used as osmotic stabilizer, the highest frequency of regeneration was achieved (8.5 percent); 80.0 percent of protoplasts were nucleated, and 20.0 percent anucleated. For Ceratorhiza sp., the largest number of protoplasts (4.0 × 10(7) protoplasts/mL) was achieved in 0.6 M NaCl, when 15 mg/mL of Lysing Enzymes and 15mg/mL of Glucanex, with 2-day-old fungal mycelium were used. The highest frequency of regeneration was 6.7 percent using 0.5 M sucrose as osmotic stabilizer; 88.8 percent of protoplasts were nucleated, and 11.2 percent anucleated.

O objetivo deste trabalho foi padronizar as condições de obtenção e regeneração de protoplastos de Epulorhiza repens e Ceratorhiza sp. Para o fungo E. repens, a maior produção de protoplastos, 8.0 x 10(6) protoplastos/mL, foi obtida em KCl 0.6 M, na presença de 15 mg/mL de "Lysing Enzymes" e micélio fúngico com 2 dias de idade. A maior freqüência de regeneração obtida foi de 8,5 por cento quando sacarose 0.5 M foi utilizada como estabilizador osmótico. Do total de protoplastos obtidos, 80 por cento eram nucleados e 20 por cento anucleados. Para Ceratorhiza sp., a maior produção de protoplastos, 4,0 x 10(7) protoplastos/mL, foi obtida em NaCl 0.6 M, na presença de 15 mg/mL de "Lysing Enzymes" e 15mg/mL de Glucanex, e micélio fúngico com 2 dias de idade. A maior freqüência de regeneração obtida foi de 6.7 por cento utilizando sacarose 0.5 M como estabilizador osmótico. Do total de protoplastos obtidos, 88.8 por cento eram nucleados e 1.2 por cento anucleados. O estabelecimento de protocolo otimizado para obtenção e regeneração de protoplastos dos fungos E. repens e Ceratorhiza sp. é importante, permitindo o estabelecimento de técnicas de transformação genética, o isolamento de mutantes, a determinação de cariótipo eletroforético e o cruzamento de linhagens.

Impacto do monocultivo de café sobre os indicadores biológicos do solo na zona da mata mineira / Impact of monocultivation coffee on biological indicators of quality soil in the zona da mata (MG), Brazil

Este estudo teve como objetivo avaliar o efeito do monocultivo de café em um latossolo, na Zona da Mata mineira, por meio de alterações em indicadores microbiológicos de qualidade do solo. Foram selecionadas quatro áreas: a) cultivo de café (Mundo Novo) durante 22 anos (C22), após uso com pastagem; b) cultivo de café (Catuaí) durante 16 anos (C16), antes mata secundária; c) mata secundária com aproximadamente de 30 anos (M30) e d) mata secundária com 40 anos (M40). Para tanto, amostras compostas de solos foram coletadas na profundidade de 0-10cm, em janeiro, abril, julho e outubro. As variáveis biológicas estudadas se mostraram sensíveis para caracterizar alterações de qualidade do solo decorrentes do monocultivo de café. Os resultados variaram com a estação do ano e o clima, e, no período mais seco, ocorreu uma redução nos valores, afetando mais drasticamente os sistemas com café. O índice de qualidade do solo demonstrou que o sistema C22 apresentou maior perda de qualidade em relação ao M40, indicando o comprometimento de sua sustentabilidade.

This study aimed to evaluate the effect of the coffee monoculture in an oxisol of the Zona da Mata (MG, Brazil) through changes in total organic carbon in the soil and microbiological indicators of soil quality. Four areas were selected: a) culture of coffee (Novo Mundo) during 22 years (C22); b) culture of coffee (Catuaí) during 16 years (C16) c) secondary forest with approximately 30 years old (M30) and d) secondary forest during 40 years (M40). Soil samples were collected in the depth of 0-10cm in January, April, July and October. The biological variables studied were sensitive to characterize changes in soil quality from coffee monoculture. The results varied with the season and climate. In the driest period, a reduction in the values occurred, affecting more drastically the coffee systems. The index of soil quality showed that the C22 system presented greater loss of quality in relation to the M40, indicating less sustainability commitment.

Laccase production by Lepista sordida

Uma lacase de Lepista sordida foi caracterizada. O fungo produziu lacase e manganês peroxidase em meio líquido com fosfato de amônio, extrato de levedura e molibdato de amônio como fontes de nitrogênio 3 dias após a inoculação. Temperatura e pH ótimos para lacase foram 45ºC e 3,5, respectivamente.

Antibacterial activity of Lentinula edodes grown in liquid medium

The antibacterial activity of 35 isolates of Lentinula edodes, a shiitake mushroom, against Bacillus subtilis was evaluated by diffusion technique in agar with a semi-solid overlay. All isolates inhibited B. subtilis and the isolate Le1 promoted the formation of the largest inhibition zone. L. edodes Le1 also presented antibacterial activity against foodborne pathogens and food contaminant bacteria, particularly Gram-positive species. The antibacterial activity of the culture filtrate after 18-25 days of cultivation of L. edodes in broth at 25§C was high. The inhibitory activity was observed only in the organic layer when the culture filtrate was partitioned between ethyl acetate and water, suggesting that the inhibitory substances have low polarity. The silica gel thin-layer zone at Rf values of 0.63-0.80, developed in chloroform - acetone - ethyl acetate - methanol = 40:5:5:2, was responsible for the antibacterial activity against B. subtilis. The inhibitory activity of L. edodes was detectable in the culture filtrate after heat treatment at 100§C for 10 min and after storage at 4§C for 120 days.