Ida Chapaval Pimentel

Identification and colonization of endophytic fungi from soybean (Glycine max (L.) Merril) under different environmental conditions

ABSTRACT A total of 297 endophytic fungi were isolated from 1728 leaf and stem fragments collected about twenty and forty days after germination from soybean (Glycine max (L.) Merril) plants grown in the field and a greenhouse. The fungi belonged to eight groups, six dematiaceous genera (Alternaria , Cladosporium , Chaetomium , Curvularia , Drechslera and Scopulariopsis ) and the non-dematiaceous genera Acremonium , Aspergillus , Colletotrichum , Fusarium , Paecilomyces and Penicillium along with some Mycelia sterilia .. There were qualitative and quantitative differences in the type and number of isolates obtained from greenhouse and field-grown plants, with more isolates being obtained from the latter. No difference was found in the number of fungi isolated from leaves and stems irrespective of where the plants was grown. For was field-grown plants, the number of isolates decreased as the plants aged and more fungi were found in tissues near the soil, while for greenhouse-grown plants the number of isolates increased as the plants aged but in this case no more fungi were isolated from those tissues nearer the soil. These results could have biotechnological relevance for the biological control of pests or plant growth promotion . Key words: Endophytic fungi, Soybean, Biological control

The capability of endophytic fungi for production of hemicellulases and related enzymes.

BackgroundThere is an imperative necessity for alternative sources of energy able to reduce the world dependence of fossil oil. One of the most successful options is ethanol obtained mainly from sugarcane and corn fermentation. The foremost residue from sugarcane industry is the bagasse, a rich lignocellulosic raw material uses for the production of ethanol second generation (2G). New cellulolytic and hemicellulytic enzymes are needed, in order to optimize the degradation of bagasse and production of ethanol 2G.ResultsThe ability to produce hemicellulases and related enzymes, suitable for lignocellulosic biomass deconstruction, was explored using 110 endophytic fungi and 9 fungi isolated from spoiled books in Brazil. Two initial selections were performed, one employing the esculin gel diffusion assay, and the other by culturing on agar plate media with beechwood xylan and liquor from the hydrothermal pretreatment of sugar cane bagasse. A total of 56 isolates were then grown at 29°C on steam-exploded delignified sugar cane bagasse (DEB) plus soybean bran (SB) (3:1), with measurement of the xylanase, pectinase, β-glucosidase, CMCase, and FPase activities. Twelve strains were selected, and their enzyme extracts were assessed using different substrates. Finally, the best six strains were grown under xylan and pectin, and several glycohydrolases activities were also assessed. These strains were identified morphologically and by sequencing the internal transcribed spacer (ITS) regions and the partial β-tubulin gene (BT2). The best six strains were identified as Aspergillus niger DR02, Trichoderma atroviride DR17 and DR19, Alternaria sp. DR45, Annulohypoxylon stigyum DR47 and Talaromyces wortmannii DR49. These strains produced glycohydrolases with different profiles, and production was highly influenced by the carbon sources in the media.ConclusionsThe selected endophytic fungi Aspergillus niger DR02, Trichoderma atroviride DR17 and DR19, Alternaria sp. DR45, Annulohypoxylon stigyum DR47 and Talaromyces wortmannii DR49 are excellent producers of hydrolytic enzymes to be used as part of blends to decompose sugarcane biomass at industrial level.

Enhancing of sugar cane bagasse hydrolysis by Annulohypoxylon stygium glycohydrolases.

The aim of this study was to develop a bioprocess for the production of β-glucosidase and pectinase from the fungus Annulohypoxylon stygium DR47. Media optimization and bioreactor cultivation using citrus bagasse and soybean bran were explored and revealed a maximum production of 6.26 U/mL of pectinase at pH 4.0 and 10.13 U/mL of β-glucosidase at pH 5.0. In addition, the enzymes extracts were able to replace partially Celluclast 1.5L in sugar cane bagasse hydrolysis. Proteomic analysis from A. stygium cultures revealed accessory enzymes, mainly belong to the families GH3 and GH54, that would support enhancement of commercial cocktail saccharification yields. This is the first report describing bioreactor optimization for enzyme production from A. stygium with a view for more efficient degradation of sugar cane bagasse.

First record of Duponchelia fovealis (Lepidoptera: Crambidae) in South America

espanolEl primer reporte de Duponchelia fovealis Zeller (Lepidoptera:Crambidae) fue por danos a la fresa (Fragaria x ananassa) en America del Sur en el Estado del Parana, Brasil. Se encontraron tres enemigos naturales para controlar D. fovealis identificados como Apanteles sp. (Hymenoptera: Braconidae), Hyaliodocoris insignis (Heteroptera: Miridae) y el hongo entomopatogenico Beauveria bassiana. EnglishThe European pepper moth Duponcheliafovealis Zeller (Lepidoptera: Crambidae) is reported for the first time in South America, in the State of Parana, Brazil. D.fovealis causes damage to strawberries and weakens the plants. Three natural enemies controlling D.fovealis were found and identified as Apanteles sp. (Hymenoptera: Braconidae), Hyaliodocoris insignis (Heteroptera: Miridae) and the entomopathogenic fungus Beauveria bassiana.

Potential of Fourier Transform Infrared Spectroscopy (FT-IR) to Differentiate Environmental Aspergillus Fungi Species A. niger , A. ochraceus , and A. westerdijkiae Using Two Different Methodologies

We assessed the ability of Fourier transform infrared spectroscopy (FT-IR) to differentiate three important and morphologically similar Aspergillus species: A. ochraceus and A. westerdijkiae, and A. niger. Fungi were processed by two methods, powdered mycelia and conidiospore–saline solution, and then recorded in a spectrometer. Second derivatives with nine points of smoothing were applied as spectra data pretreatment. Partial least squares regression was used for the species comparison models and a prediction test was used to evaluate the models. The powdered-mycelia methodology correctly identified 100% of the prediction test set to discriminate A. niger from A. ochraceus and A. westerdijkiae; in addition, it had a 86.6% success rate in discriminating A. ochraceus and A. westerdijkiae. This is the first time a study assessed the ability of FT-IR to differentiate A. niger, A. ochraceus, and A. west-erdijkiae, and we believe this technique is very promising for classifying and distinguish fungi isolates.

Electronic Detection of Drechslera sp. Fungi in Charentais Melon (Cucumis melo Naudin) Using Carbon-Nanostructure-Based Sensors

The development of chemical sensor technology in recent years has stimulated an interest regarding the use of characteristic volatiles and odors as a rapid and early indication of deterioration in fruit quality. The fungal infestation by Drechslera sp. in melons is a severe problem, and we demonstrate that electronic sensors based on carbon nanostructures are able to detect the presence of these fungi in melon. The responses of sensor conductance G and capacitance C at 27 kHz were measured and used to calculate their ΔG and ΔC variation over the full melon ripening process under shelf conditions with proliferation of Drechslera sp. fungi. The sensor response showed that these fungi can be electronically identified in charentais melon, constituting an effective and cheap test procedure to differentiate between infected and uninfected melon.

Xylanase production by endophytic Aspergillus niger using pentose-rich hydrothermal liquor from sugarcane bagasse

Fungal xylanases have been widely studied and various production methods have been proposed using submerged and solid-state fermentation. This class of enzyme is used to supplement cellulolytic enzyme cocktails in order to enhance the enzymatic hydrolysis of plant cell walls. The present work investigates the production of xylanase and other accessory enzymes by a recently isolated endophytic Aspergillus niger DR02 strain, using the pentose-rich liquor from hydrothermal pretreatment of sugarcane bagasse as carbon source. Batch and fed-batch submerged cultivation approaches were developed in order to minimize the toxicity of the liquor and increase enzyme production. Maximum xylanase activities obtained were 458.1 U/mL for constant fed-batch, 428.1 U/mL for exponential fed-batch, and 264.37 U/mL for pulsed fed-batch modes. The results indicated that carbon-limited fed-batch cultivation can reduce fungal catabolite repression, as well as overcome possible negative effects of toxic compounds present in the pentose-rich liquor. Enzymatic panel and mass spectrometric analyses of the fed-batch A. niger secretome showed high levels of xylanolytic enzymes (GH10, GH11, and GH62 Cazy families), together with cellobiohydrolase (G6 and GH7), β-glucosidase, β-xylosidase (GH3), and feruloyl esterase (CE1) accessory enzyme activities. The yields of glucose and xylose from enzymatic hydrolysis of hydrothermally pretreated sugarcane bagasse increased by 43.7 and 65.3%, respectively, when a commercial cellulase preparation was supplemented with the A. niger DR02 constant fed-batch enzyme complex.

Paecilomyces niveus Stolk & Samson, 1971 (Ascomycota: Thermoascaceae) as a pathogen of Nasonovia ribisnigri (Mosley, 1841) (Hemiptera, Aphididae) in Brazil

Nasonovia ribisnigri is a key pest of lettuce (Lactuca sativa L.) in Brazil that requires alternative control methods to synthetic pesticides. We report, for the first time, the occurrence of Paecilomyces niveus as an entomopathogen of the aphid Nasonovia ribisnigri in Pinhais, Paraná, Brazil. Samples of mummified aphids were collected from lettuce crops. The fungus P. niveus (PaePR) was isolated from the insect bodies and identified by macro and micromorphology. The species was confirmed by sequencing Internal Transcribed Spacer (ITS) rDNA. We obtained a sequence of 528 bp (accession number HQ441751), which aligned with Byssochlamys nivea strains (100% identities). In a bioassay, 120 h after inoculation of N. ribisnigri with pathogenic P. niveus had an average mortality of 74%. The presence of P. niveus as a natural pathogen of N. ribisnigri in Brazil suggests that it may be possible to employ P. niveus to minimize the use of chemical insecticides.

Occurrence of Candida orthopsilosis in Brazilian tomato fruits (Lycopersicum esculentum Mill.)

We aimed to isolate and identify yeasts found in the tomato fruit in order to obtain isolates with biotechnological potential, such as in control of fungal diseases that damage postharvest fruits. We identified Candida orthopsilosis strains LT18 and LT24. This is the first report of this yeast on Lycopersicum esculentum fruits in Brazil.

Fungos endofíticos associados a acículas de Pinus taeda

ABSTRACT The present work aimed to study the endophytic fungi in Pinustaeda needles and to evaluate the effect of sample points in the tree.Samples were collectd in two different heights (30-50 cm and 100-130cm over ground) and cardinal positions (North, South, East and West)in plants with 18 months old, located at Colombo, PR, Brazil. Theneedles were sucessively washed in sterile destilled water, 70 % ethanol,NaHClO 3 %, 70 % ethanol and sterile destilled water. Needlefragments of 10 mm of lenth were plated in PDA medium, incubatedat 28 °C, fotophase 12h to 15 days. The reproductive structures offungi were produced by microculture technique. Seventeen generaPimentel, I. C.; Figura, G.; Auer, C. G. Endophytic fungi associated to Pinus taeda needles. Summa Phytopathologica, v.36, n.1, p.xx-xx, 2010. Keywords: forest, microorganisms, phyloplane, pine. Palavras-chave adicionais: filoplano, floresta, microrganismos, pinus. RESUMO O presente trabalho objetivou estudar os fungos endofiticos emaciculas de arvores jovens de