Efeito da solarização e do brometo de metila sobre a comunidade de fungos do solo

A microbiota do solo é de grande importância no desenvolvimento de culturas. Os métodos de controle, químico (brometo de metila) e físico (solarização), alteram essa microbiota. O presente trabalho objetivou estudar o comportamento da comunidade de fungos em solo solarizado e fumigado (brometo de metila). O delineamento experimental foi de blocos ao acaso, com três tratamentos (solarização, brometo de metila e testemunha) e sete repetições. A comunidade de fungos do solo foi avaliada de forma quantitativa e qualitativa, em três momentos (antes, durante e após a solarização) com amostras coletadas de três profundidades (0-5; 10-15 e 20-25 cm). Durante a solarização ocorreu uma redução na comunidade de fungos do solo, em termos quantitativos, em todas as camadas amostradas. No entanto, essa diminuição foi mais significativa na camada superficial (0-5cm). em termos qualitativos, a solarização reduziu também o número de diferentes espécies de fungos do solo, mas na camada de 20-25 cm, essa diminuição foi a zero aos 56 dias de avaliação. A recolonização da microbiota do solo, em termos quantitativos, foi maior no tratamento com brometo de metila do que nos demais. Entretanto, esse aumento não foi o mesmo em termos qualitativos. Nos tratamentos solarizado e testemunha, o aumento na comunidade de fungos do solo foi acompanhado pela diversificação de espécies fúngicas.

Atividade da celulase de fungos isolados do solo da Estação Ecológica de Juréia-Itatins, São Paulo, Brasil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Fungos anamorfos do solo da região dos lagos no Município de Santa Gertrudes, SP, Brasil

O solo do pólo cerâmico no município de Santa Gertrudes, SP, tem sido poluído há décadas por diversos elementos químicos, principalmente chumbo e zinco. Foram realizadas quatro coletas de amostras de solo, duas durante a época chuvosa e duas na seca, em cinco locais, de novembro de 2002 a junho de 2003, determinando-se temperatura, pH, teores de chumbo e zinco e a umidade do solo. Os fungos foram isolados pelo método de Warcup, modificado pelo preparo de suspensões aquosas de solo (1:10) e aplicação de 1 cm³ das suspensões sobre malte agar (2%), adicionado de Zn(NO3)2 e Pb(NO3)2 em concentrações crescentes: 0, 100, 200, 500 e 1.000 mg dm-3. Após cinco dias de incubação a 25 ºC, as colônias foram purificadas e identificadas. Foram obtidos 70 táxons de fungos anamorfos, com 70% de similaridade entre as micotas obtidas nos meios com os dois metais. Foram isolados 43 táxons nos meios de cultura com Pb(NO3)2, com predominância deles nas concentrações mais elevadas (500 a 1.000 mg dm-3). Foram obtidos 63 táxons nos meios com Zn(NO3)2, principalmente nas concentrações moderada e elevada (200 e 500 mg dm-3). Prevaleceram espécies de Trichoderma, de Penicillium e diversos fungos que são encontrados associados a substratos vegetais em decomposição. A tendência de se obter número elevado de táxons em meios de cultura com concentrações moderadas a elevadas de Zn e Pb pode ser justificada pela existência de bem adaptada e competitiva micota do solo, caracterizada por elevada capacidade de tolerância aos metais e eficiente habilidade sapróbia competitiva.

Crescimento, esporulação e viabilidade de fungos entomopatogênicos em meios contendo diferentes concentrações do óleo de nim (Azadirachta indica)

A associação de extratos de origem vegetal com fungos entomopatogênicos pode aumentar a eficiência do controle biológico de pragas, reduzir custos e impactos ambientais. No presente trabalho, avaliou-se, através da concentração inibitória mínima, o efeito do óleo de nim (NIM-I-GO) sobre o crescimento, esporulação e viabilidade de Metarhizium anisopliae, Beauveria bassiana e Paecilomyces farinosus. Utilizou-se o meio BDA, contendo diferentes concentrações de óleo de nim (C1: 5% de óleo de nim, e sucessivamente concentrações iguais a ½ da concentração anterior, até C11: 0,0048% de óleo de nim). O óleo de nim reduziu o crescimento de colônias de B. bassiana e P. farinosus, que não diferiram significativamente do controle apenas na concentração C11, mas para M. anisopliae o mesmo efeito foi observado com 0,039% de óleo de nim (C8). A esporulação também foi significativamente reduzida pelo óleo de nim, exceto na concentração C11 para B. bassiana; contudo, não se verificou efeito do óleo na viabilidade de esporos dos fungos.

Virulence profile of ten Paracoccidioides brasiliensis isolates: association with morphologic and genetic patterns

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Efeitos da amonização sobre a ocorrência de fungos, composição química e digestibilidade in vitro de fenos de grama Seda (Cynodon dactylon (L.) Pers.)

The experiment was conducted with grama seda (Cynodon dactylon (L.) Pers.) hays stored with a low moisture content (12-15%) and without chemical treatment, and hays stored with a high moisture content (20-25%) and treated with anhydrous ammonia (NH3) al 0.5 and 1.0% of DM, and urea at 0.9 and 1.8% of DM. At 65 days after treatment (AT) under a plastic cover, the bales were opened and samples were taken at 3, 15 and 30 days to determine the chemical composition and in vitro digestibility (IVDMD) of the hays. For the identification of fungi, samples were taken at 0, 15 and 30 days AT. The data were analyzed according to a split-plot design with the effects of the chemical treatments studied in the main plot and the effects of the periods of post-treatment studied in the sub-plots, Fourteen genera of fungi were observed in the hays, not treated and treated with NH3 and urea, with a higher occurrence of Cladosporium, Curvularia, Aspergillus, and Penicillium. Treatment with anhydrous ammonia and 1.8% urea controlled the occurrence of Aspergillus; however, Penicillium decreased in hays treated with ammonia 30 days AT. Ammoniation did not influence the contents of ADF, cellulose and lignin in the hays, but NDF and hemicellulose decreased with the use of ammonia 30 days AT. The CP contents and the IVDMD increased with ammoniation. The CP contents decreased in hays treated with NH3 as days AT increase, while hays treated with urea did not change.

Produção de biomassa por fungos Filamentosos em meio de vinhaça de cana-de-açúcar suplementado com melaço

Three species of filamentous fungi, Aspergillus niger, Penicillium fellutanum and Mucor hiemalis, were selected and cultivated in vinasse media with different addition of molasses, pasteurized to 85°C for 30 minutes and with pH = 5.0. The microorganisms, previously adapted to the respective medium for 48 hours, from a solution of 107 spores.ml-1, were cultivated in pure and mixed cultures in Erlenmeyer vessel of 500ml, to 30°C, with constant agitation of 170 rpm, for 24, 48 and 72 hours, with four repetition for each samples. The biomass was separated by vacuum filtration in filter Whatman #1 and dried in oven at 105°C until right weight, the obtained liquid was submited to COD analysis. The datas were statistically analysed using a response surface methodology, to improve the effect on the molasses proportion and culture time, in the biomass production by microorganism in research. According to the obtained results (5.02% of molasses, 55.59h, 70% of spores solution of A. niger and 30% of spores solution of P. fellutanum), cultivating was carried out in Microferm Fermentor New Brunswick for 48 hours at 300 rpm, aired at 1v/v/m, using 5 liters of medium added with 5.0% of molasses on the conditions above described. The average of the results obtained (6.81g.l-1) was higher than the confidence interval (5.937 ; 6.369) and was inside the prediction interval (4.471 ; 7.834) both of them significant at 95% by the statistical test employed.

Efeito de biofertilizantes sobre o crescimento micelial e a germinação de esporos de alguns fungos fitopatogênicos

The biofertilizer was produced through anaerobic fermentation of cow manure adding milk, sugar, salts, cow liver parts and bone powder. After 73 days of fermentation it was evaluated the effect on micelial growth of Pythium aphanidermatum, Alternaria solani, Stemphylium solani, Septoria licopersici, Sclerotinia sclerotiorum, Botrytis cinerea, Rhizoctonia solani, Fusarium oxysporum f. sp. phaseoli and spores germination of B. cinerea, A. solani, Hemileia vastatrix and Coleosporium plumierae. In relation to micelial growth inhibition, the growth rate was calculated and it was found that, in general, concentrations over 10% caused a total inhibition of growth for the majority of fungi assayed. In case of spores germination, biofertilizer concentration over 20% has inhibited completely the germination of B. cinerea, over 10% inhibited A. solani, 5 and 1% of C. plumierae and H. vastatrix, respectively. Three different biofertilizers were also tested and one of them was less effective, which was the one produced with manure from confined cows opposed to the others produced with grazing cows.

Ausência de patogenicidade de Xylella fastidiosa da escaldadura da folha da ameixeira na cultivar de pessegueiro flordasun

Xylella fastidiosa associated to plum leaf scald is reported to belong to the same group of the strain that causes the phony disease of peach. Plants of plum cultivars Santa Rosa and Harry Pickstone and peach cultivar Flordasun, grafted on peach rootstock, were inoculated by using buds collected from plum plants severely infected with X. fastidiosa. Peach plants did not develop symptoms of phony disease, after four years in the greenhouse. In contrast, plum plants from both cultivars inoculated either in the rootstock or in the canopy developed leaf scald symptoms. DAS-ELISA tests with antibody against X. fastidiosa and isolation on BCYE medium indicated the presence of the bacterium in plum tissues. These tests were negative for Flordasun peach for both stem and root samples.

Isolamento de fungos produtores de ácido γ-linolênico de solo da Estação Ecologica de Juréia-Itatins, SP

Fungi producing γ-linolenic acid (GLA) were isolated from soil of the Ecological Station of Juréia-Itatins, SP. This essential fatty acid has aroused great interest due to its increasing by applications in pharmaceutical industry. The GLA production by zygomycetous fungi is an alternative way of comparing seed extraction. Thirty-two zygomycetous strains of Mucorales were isolated, most of them belonging to Mucor genus. The GLA production was evaluated after 4 days of incubation at 25°C on a rotary shaker at 150 rpm in medium containing 2% glucose, and 1% yeast extract, following new medium addition (20%) and incubation for an additional period of 3 days at 12°C, without agitation. The GLA production varied according to the microorganism and the strain.

Isolamento de fungos produtores de enzimas pectinolíticas

Soil samples collected in the campus, UNESP, Araraquara, SP, were employed to isolate and characterize fungi strains with potential pectinolytic enzymes. These enzymes have arisen great interest due to its increasing application in the food industry. Two hundred forty six strains were isolated based on the appearance of colony on PDA medium, morphology (septate mycelia, nonseptate conidiophore, black conidia, and clublike spore-bearing head), after 48 h of growth at 30°C. Strains were selected in solid medium containing pectin citrus as sole carbon source and 0.5% rutenium red. The characterization of pectinolytic production was performed in solid culture and batch fermentation medium containing pectin citrus. The enzyme pectinolytic production was evaluated at 30°C, without agitation in 100 mL of medium containing 2% pectin citrus, 0.2% ammonium sulphate, 0.2% magnesium sulphate, and 0.05% potassium phosphate. The maximum pectinolytic activity (15U/mL) was observed in the medium after Aspergillus sp CFCF-0492 growth, while Aspergillus sp CFCF-CC1 showed the higher level of the final biomass. The pectinolytic activity is more preserved when the fungi-spores were maintained in agar-Czapeck medium.

Sementes de feijão-caupi (Vigna unguiculata L. (Walp), tratadas com extrato de folhas de nim (Azadirachta indica A. Juss.) avaliação da germinação e da incidência de fungos

This study aimed to evaluate the effect of aqueous extract of neem on germination and fungi incidence on seeds of three cultivars (Serrinha, BR 17 and Maranhão) of cowpea. Neem leaves were dryed, crushed and prepared dilutions of 0.5; 1.0; 2.0, 4.0 g dm -3and control. The fungi incidence was evaluated by the test filter paper and germination according to the Rules for Seeds Testing (Regras para Análise de Sementes). In the three cultivars analyzed, reduction in the incidence of Aspergillus sp and Fusarium sp was observed. In relation to the influence of extracts of neem leaves on seed germination, significant effect of extract in Maranhão cultivar was observed, where all concentrations differed from the control, and propovided a considerable increase in the percentage of normal seedlings. It was concluded that the leaf extract of neem was effective in controlling Aspergillus sp, Fusarium sp , Phoma sp and Macrophomina phaseolina at different concentrations in different cultivars and seed germination was stimulated for the Maranhão cultivar.

Estabelecimento de fungos nematófagos aplicados no campo para o controle dos nematoides-chaves dos citros no Brasil

Monitoring the survival of nematophagous fungi is needed to establish periods of reapplication of formulations of nematophagous fungi to control the citrus nematode in the field. We monitored the survival of fungi: Arthrobotrys robusta, A. oligospora, A. musiformis Dactylella leptospora and Monacrosporium eudermatum in plots treated with 1, 2, 4, 6 liters of the formulation of fungi/plant or witness without the application, during the period of nine months with the first assessment six months after application and the other with intervals of three months after the first evaluation. The fungus D. leptospora was found only in the evaluation of 6 months after treatment application, indicated a short survival time in the soil. However, the isolated A. robusta, A. musiformis and A. oligospora were recovered in all evaluations and especially in plots treated with higher doses of the formulation and witness. Monacrosporium eudermatum was recovered in all experimental periods and even in assessing the witness portion of nine months after application. The fact of the presence of species of Arthrobotrys and M. eudermatum in control plots indicates that native species that were already orchard.

Fungos endofíticos: Uma fonte inexplorada e sustentável de novos e bioativos produtos naturais

Endophytic fungi are a rich source of new and biologically active natural products. They colonize a relatively unexplored ecological habitat and their secondary metabolism is particularly active, presumably due to metabolic interactions with their hosts. In the course of our continuing investigations for new and bioactive compounds from endophytic fungi from brazilian flora Alibertia macrophylla, Caseria sylvestris, Ocotea corymbosa, Cassia spectabilis, Piper aduncum, Cryptocaria mandioccana, Xylopia aromatica and Palicourea marcgravii were investigated. Forty two natural products were isolated and their structures were established on the basis of comprehensive spectral analysis, mainly using 1D and 2D NMR experiments. The compounds were tested in their antifungal, antioxidant, anticholinesterasic and anticancer activities.

Descrição da diversidade de fungos associados a formigas Attini por método independente de cultivo

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)