Reação de clones de cajueiro-anão a isolados de Colletotrichum gloeosporioides em ambiente controlado

The cashew (Anacardium occidentale L.) crop is an important source of income for the population of the Brazilian Northeast, and anthracnose disease caused by Colletotrichum gloeosporioides leads to significant production loss. However, there is little information on either the host resistance or the variation in the aggressiveness of the pathogen under controlled environment. The reaction of commercial (CCP-06, CCP-09, CCP-76 and CCP-1001) and one non-commercial (CAP-14) dwarf cashew clones was assessed against 36 isolates of this fungus controlled environmental conditions. All the isolates, including those from hosts other than cashew, were able to cause lesions on leaves and stems of most clones, albeit to different degrees. Clone CCP-06 was the most susceptible, while clone CCP-1001 showed a level of resistance to a number of the isolates, including isolate 905, while isolates 910 and 912 were aggressive to all clones. Injury increased the susceptibility of the clones to all isolates, indicating that resistance also might be associated with structural barriers that hinder penetration. Ripened cashew apples (8-week-old), of commercial clones were susceptible to isolates 905 and 910. Immature pseudo-fruits (2-week-old), with exception of clone CCP-76 which was susceptible to both isolates showed resistance against these isolates, suggesting the presence of structural and chemical barriers. Developed nuts (8-week-old), however, were more resistant than immature nuts (2-week-old) to both isolates, probably due to their thicker exocarp cuticle and reduced number of stomatal pores.A cultura de caju (Anacardium occidentale L.) é uma fonte de renda importante para a população do Nordeste brasileiro, sendo a antracnose causada por Colletotrichum gloeosporioides a doença que mais conduz a perdas de sua produção. Entretanto, há pouca informação para a resistência desse hospedeiro ou para a variação na agressividade do patógeno em ambiente controlado. A reação de clones comerciais (CCP-06, CCP-09, CCP-76 e CCP-1001) e um não comercial (CAP-14) de cajueiros anão-precoce, contra 36 isolados desse fungo, foi avaliada sob condições controladas. Todos os isolados, incluindo os provenientes de diferentes hospedeiros, foram capazes de causar lesões sobre folhas e hastes da maioria dos clones, ainda que em graus diferenciados. O clone CCP-06 foi o mais suscetível, enquanto o clone CCP-1001 foi resistente a mais isolados, incluindo o 905, enquanto os isolados 910 e 912 foram agressivos a todos os clones testados. A injúria mecânica das folhas aumentou a suscetibilidade dos clones a todos os isolados, indicando que a resistência pode também estar associada a barreiras estruturais que impedem a penetração. Os pseudofrutos amadurecidos (8 semanas) dos clones comerciais avaliados, foram suscetíveis a ambos os isolados testados (905 e 910), mas os jovens (2 semanas), com exceção daqueles do clone CCP-76, suscetíveis aos dois isolados, apresentaram resistência a ambos, sugerindo a ação de obstáculos estruturais e químicos diferenciados. As castanhas desenvolvidas (8 semanas), no entanto, foram mais resistentes a ambos os isolados do que as jovens (2 semanas), talvez devido à espessa cutícula do exocarpo e baixo número de estômatos

Decomposição fúngica de ácido tânico e outros compostos em efluente agroindustrial - doi: 10.4025/actascitechnol.v33i2.10117

During the processing of raw materials from the sugar-alcohol industry, large quantities of wastewater is produced, which is inappropriate to release into water bodies without previous suitable treatment. The bioremediation is used to decompose organic waste until an innocuous condition or to a concentration below the limit under legislation; moreover fungi have very important role in this strategy due to the secretion of hydrolytic enzymes. In the present study, we evaluated the behavior of fungi isolated from residuals of the waste treatment station from a sugar-alcohol industry in face to the phenols degradation, as tannic acid and other compounds of agri-industrial wastewater supplemented with specific nutrients. Among different fungi, those identified as Aspergillus sp. and Cladosporium sp. presented the best rates of production of enzymes that degrade tannic acid, such as laccase, while Mucor sp. was better to remove the Chemical Oxygen Demand (COD) and the total phenol content, followed by Cladosporium sp., Phanerochaeta chrysosporium and Geotrichum candidum.Durante o processamento da matéria-prima da indústria sucroalcooleira, gera-se grande quantidade de efluentes com qualidades que impossibilitam seu lançamento em corpos de água sem o tratamento prévio. A biorremediação é usada para decompor resíduos orgânicos até um estado inócuo ou abaixo da concentração limite da legislação, tendo os fungos papel muito importante nessa estratégia por secretarem enzimas hidrolíticas. Neste trabalho, avaliou-se o comportamento de fungos isolados de resíduos da estação de tratamento de efluentes de uma indústria sucroalcooleira frente à degradação de fenóis como o ácido tânico e de outros compostos de efluentes agroindustriais suplementados com nutrientes específicos. Dentre diferentes isolados, aqueles identificados como Aspergillus sp. e Cladosporium sp. apresentaram as melhores taxas de produção de enzimas degradadoras de ácido tânico, como a lacase, por exemplo, enquanto Mucor sp. foi o que melhor removeu a Demanda Química de Oxigênio (DQO) e o conteúdo de fenóis totais, seguido por Cladosporium sp., Phanerochaeta chrysosporium e Geotrichum candidum

Ação de Micoflora de efluentes agroindustriais sobre diferentes corantes e substratos lignocelulósicos - doi: 10.4025/actascibiolsci.v33i4.6187

Extracellular enzymes of fungi are important for survival in inhospitable environments, as they are able to degrade recalcitrant compounds. Filamentous fungi secrete hydrolases and phenoloxidases that are capable of degrading complexes of aromatic structures, such as certain xenobiotics. The purpose of this study was to test different dyes (methylene blue, Azure B, Malachite Green and Crystal Violet), replacing the compound Poly R478 in the method of selection of phenol decomposer microorganisms in solid medium, and compare this activity of the mycoflora of effluents from sugar-alcohol industry, to the ones of other fungi acquired in official collection. The tested dyes proved to be excellent substitutes for Poly R478. The isolate that showed more intense decolorant activity than the diameter of its growth (Cladosporium sp.) was then tested on two natural and one synthetic substrate (sugarcane bagasse, sawing wood, and methylene blue) in liquid medium. This isolate removed high concentrations of reducing sugars, proteins and total phenols, and reduced the COD in medium containing sawdust as natural substrate of phenols. This fungus, therefore, seems promising to form consortia for co-metabolism and bioremediation of effluents in which there is a presence of phenolic or other recalcitrant compounds with similar structure to lignin.Enzimas extracelulares de fungos são importantes para sua sobrevivência em ambientes inóspitos, sendo capazes de degradar compostos recalcitrantes. Fungos filamentosos secretam hidrolases e fenoloxidases capazes de degradar complexos de estruturas aromáticas, como de alguns xenobióticos. O propósito deste trabalho foi testar diferentes corantes (Azul de Metileno, Azure B, Verde Malaquita e Cristal Violeta), em substituição ao composto Poly R478, no método de seleção de microrganismos degradadores de fenóis em meio sólido, além de comparar tal atividade de Micoflora isolada de efluentes de indústria sucroalcooleira com a de outros fungos adquiridos em coleção oficial. Os corantes testados revelaram-se ótimos substitutos do Poly R478. O isolado que apresentou atividade descolorante mais intenso do que a do diâmetro de seu crescimento (Cladosporium sp.) foi testado, então, em meio líquido frente a dois substratos naturais e um sintético (bagaço de cana, serragem de madeira e azul de metileno). Este removeu altas concentrações de glicídios redutores, proteínas e fenóis totais, além de reduzir a DQO em meio com serragem de madeira como substrato fenólico natural. Tal fungo, portanto, mostrou-se promissor para compor consórcios visando cometabolismo e biorremediação de efluentes nos quais há presença de compostos fenólicos ou outros recalcitrantes com estrutura semelhante à de lignina

Ação de Micoflora de efluentes agroindustriais sobre diferentes corantes e substratos lignocelulósicos =Action of mycoflora from agri-industrial effluents on different dyes and lignocellulosic substrates

Enzimas extracelulares de fungos são importantes para sua sobrevivência em ambientes inóspitos, sendo capazes de degradar compostos recalcitrantes. Fungos filamentosos secretam hidrolases e fenoloxidases capazes de degradar complexos de estruturas aromáticas,como de alguns xenobióticos. O propósito deste trabalho foi testar diferentes corantes (Azul de Metileno, Azure B, Verde Malaquita e Cristal Violeta), em substituição ao composto Poly R478, no método de seleção de microrganismos degradadores de fenóis em meio sólido, além de comparar tal atividade de Micoflora isolada de efluentes de indústria sucroalcooleira com a de outros fungos adquiridos em coleção oficial. Os corantes testados revelaram-se ótimos substitutos do Poly R478. O isolado que apresentou atividade descolorante mais intenso do que a do diâmetro de seu crescimento (Cladosporium sp.) foi testado, então, em meio líquido frente a dois substratos naturais e um sintético (bagaço de cana, serragem de madeira e azul de metileno). Este removeu altas concentrações de glic��dios redutores, proteínas e fenóis totais, além de reduzir a DQO em meio com serragem de madeira como substrato fenólico natural. Tal fungo, portanto, mostrou-se promissor para compor consórcios visando cometabolismo ebiorremediação de efluentes nos quais há presença de compostos fenólicos ou outros recalcitrantes com estrutura semelhante à de lignina.<br><br>Extracellular enzymes of fungi are important for survival in inhospitable environments, as they are able to degrade recalcitrant compounds. Filamentous fungi secrete hydrolases and phenoloxidases that are capable of degrading complexes of aromatic structures, such as certain xenobiotics. The purpose of this study was to test different dyes (methylene blue, Azure B, Malachite Green and Crystal Violet), replacing the compound Poly R478 in the method of selection of phenol decomposer microorganisms in solid medium, and compare this activity of the mycoflora of effluents from sugar-alcohol industry, to the ones of other fungi acquired in official collection. The tested dyes proved to be excellent substitutes for Poly R478. The isolate that showed more intense decolorant activity than the diameter of its growth (Cladosporium sp.) was then tested on two natural and one synthetic substrate (sugarcane bagasse, sawing wood, and methylene blue) in liquid medium. This isolate removed highconcentrations of reducing sugars, proteins and total phenols, and reduced the COD in medium containing sawdust as natural substrate of phenols. This fungus, therefore, seems promising to form consortia for co-metabolism and bioremediation of effluents in which there is a presence of phenolic or other recalcitrant compounds with similar structure to lignin

Production of emulsifier by a strain of Pseudomonas aeruginosa (C1 LBPVMA-UFAL) using lubricant oil as main carbon source - DOI: 10.4025/actascitechnol.v32i1.7548

The intention of this work was to evaluate the growth of Pseudomonas aeruginosa (C1 LBPVMA-UFAL) on lubricant oil and verify the production of rhamnolipid biosurfactant. Tests in solid medium containing lubricant oil supplemented with different sources of nitrogen were used to evaluate the growth of P. aeruginosa. The growth medium used for production of rhamnolipid was (g L-1): yeast extract, 0.1; NaCl, 1.0; MgSO4, 0.2; MnSO4.H2O, 0.02; 0.5% lubricant oil (w v-1). The biosurfactant concentration was detected 24h after the inoculation, during the exponential phase, with the maximum value obtained up to 120h, although no drastic alteration of pH had been verified. The emulsifier activity was also first detected after 24h of incubation, with maximum production after 120h. The characterization of the produced biosurfactant was performed through thin layer chromatography, which showed the presence of two spots with Rf values equal to 0.71 and 0.5, revealed by reagents specific to rhamnolipids. These results suggested that two types of rhamnolipidic biosurfactant are produced by the strain of P. aeruginosa in limited conditions of nutrients, able to use lubricant oil as main carbon source. This bacterium, isolated from agro-industrial effluent, showed potential to bioremediation assays of contamination with petrol and his derivates

THE FUNGAL ABILITY FOR BIOBLEACHING/BIOPULPING/BIOREMEDIATION OF LIGNIN-LIKE COMPOUNDS OF AGRO-INDUSTRIAL RAW MATERIAL

Lignin is present in plant cell secondary wall, associated to carbohydrates preventing their efficient hydrolysis, and cellulose pulp manufacture basically consists in breaking down the middle lamella of plant cells, individualizing fibers such as cellulose from the other biopolymers. Different levels of lignocellulose are found in plant residues and they can be decomposed by extracellular fungal lignin modifying enzymes, used as a tool to reduce waste materials in contaminated soils and effluents. In the paper mill industries, for instance, they are a suitable or complementary alternative to the traditional methods of pulping/bleaching, contributing to improve paper strength as well as to reduce the pitch content, the quantity of chemicals and the consume of electrical energy. The aim of this review was to describe the fungal degradation of lignocellulosic like-material, the non-specific enzymatic aspects of the attack of wood and agricultural wastes, the fungal ability for biosorption and bioconversion, and its applications in the pulp/paper industry and bioremediation