289 research outputs found

    DNA fingerprinting of Paecilomyces strains of potential use for the biological control of pests.

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    Made available in DSpace on 2018-06-06T00:58:57Z (GMT). No. of bitstreams: 1 ID278211.pdf: 310735 bytes, checksum: ad02f1cb9a27b440fe5a2ad2c11149d8 (MD5) Previous issue date: 2007-01-0

    Monomorphic subtelomeric DNA in the filamentous fungus, Metarhizium anisopliae, contains a RecQ helicase-like gene.

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    In most filamentous fungi, telomere-associated sequences (TASs) are polymorphic, and the presence of restriction fragment length polymorphisms (RFLPs) may permit the number of chromosome ends to be estimated from the number of telomeric bands obtained by restriction digestion. Here, we describe strains of Metarhizium, Gliocladium and Paecilomyces species in which only one or a few telomeric bands of unequal intensity are detectable by Southern hybridization, indicating that interchromosomal TAS exchange occurs. We also studied an anomalous strain of Metarhizium anisopliae, which produces polymorphic telomeric bands larger than 8 kb upon digestion of genomic DNA with XhoI. In this case, the first XhoI site in from the chromosome end must lie beyond the presumed monomorphic region. Cloned telomeres from this strain comprise 18?26 TTAGGG repeats, followed at the internal end of the telomere tract by five repeats of the telomere-like sequence TAAACGCTGG. An 8.1-kb TAS clone also contains a gene for a RecQ-like helicase, designated TAH1, suggesting that this TAS is analogous to the Y elements in yeast and the subtelomeric helicase ORFs of Ustilago maydis (UTASRecQ) and Magnaporthe grisea (TLH1). The TAS in the anomalous strain of M. anisopliae, however, appears distinct from these in that it is found at most telomeres and its predicted protein product possesses a significantly longer N-terminal region in comparison to the M. grisea and U. maydis helicases. Hybridization analyses showed that TAH1 homologues are present in all other anomalous M. anisopliae strains studied, as well as in some other polymorphic strains, where the recQ-like gene also appears to be telomere-associated.Published online: 2 June 2005

    A mutant of Metarhizium anisopliae var. acridum with enhanced submerged conidiation.

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    Made available in DSpace on 2018-06-06T01:01:38Z (GMT). No. of bitstreams: 1 ID278831.pdf: 343982 bytes, checksum: 1b1ebb921fe53464e93c15e17e4d406c (MD5) Previous issue date: 2007-01-16bitstream/item/178116/1/ID-27883-1.pd

    Effects of supplements with different protein contents on nutritional performance of grazing cattle during the rainy season

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    The objective of this study was to evaluate the effects of supplements with different crude protein (CP) contents on grazing cattle intake, digestibility, ruminal fermentation pattern, and nitrogen (N) metabolism characteristics during the rainy season. Five ruminal and abomasal cannulated Holstein×Zebu steers (296 kg body weight, BW) were used in a 5×5 Latin square design. The animals grazed five signal grass paddocks (0.34 ha). The five treatments evaluated were: Control (no supplement) and 1.0 g of supplement/kg BW with 0, 330, 660, and 1,000 g of CP/kg as-fed. The supplement was composed of starch, soybean meal, urea, and ammonium sulphate. There was a positive linear effect (p≤0.033) of the CP content in the supplements on the organic matter (OM), CP, and digested OM intakes. The provision of supplements did not increase (p≥0.158), on average, total and ruminal digestibilities of OM and CP. However, the increase in CP content in the supplements caused a positive linear effect (p≤0.018) on ruminal digestibilities of OM and CP. Additionally, a quadratic effect of the CP contents of the supplements were observed (p = 0.041) for the ruminal digestibility of neutral detergent fiber corrected for ash and protein, with the highest estimate obtained with the CP content of 670 g/kg. The supply of supplements increased (p<0.001) the ruminal ammonia N concentration, which also changed linearly and positively (p<0.001) according to increase in CP content in the supplements. The apparent N balance and relative N balance (g/g N intake) were not, on average, changed (p≥0.164) by the supplements supply. However, both showed a tendency of a linear increase (p≤0.099) with increasing supplement CP content. The supplements increased (p = 0.007) microbial N production in the rumen, which also changed linearly and positively (p = 0.016) with increasing supplement CP content. In conclusion, protein supplementation in grazing cattle during the rainy season, while stimulating voluntary forage intake, results in higher efficiency of N utilization when compared to energy supplementation. This is a possible response to increased microbial protein synthesis in the rumen and improved N status in the animal body

    Trichoderma from Brazilian garlic and onion crop soils and description of two new species: Trichoderma azevedoi and Trichoderma peberdyi.

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    Fifty four Trichoderma strains were isolated from soil samples collected from garlic and onion crops in eight different sites in Brazil and were identified using phylogenetic analysis based on combined ITS region, tef1-α, cal, act and rpb2 sequences. The genetic variability of the recovered Trichoderma species was analysed by AFLP and their phenotypic variability determined using MALDI-TOF. The strain clusters from both typing techniques coincided with the taxonomic determinations made from phylogenetic analysis. The phylogenetic analysis showed the occurrence of Trichoderma asperellum, Trichoderma asperelloides, Trichoderma afroharzianum, Trichoderma hamatum, Trichoderma lentiforme, Trichoderma koningiopsis, Trichoderma longibrachiatum and Trichoderma erinaceum, in the soil samples. We also identified and describe two new Trichoderma species, both in the harzianum clade of section Pachybasium, which we have named Trichoderma azevedoi sp. nov. and Trichoderma peberdyi sp. nov. The examined strains of both T. azevedoi (three strains) and T. peberdyi (12 strains) display significant genotypic and phenotypic variability, but form monophyletic clades with strong bootstrap and posterior probability support and are morphologically distinct from their respective most closely related species

    Uso de concentrador solar para secagem de bagaço de cana-de-açúcar.

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    O setor sucroalcooleiro energético fornece importantes produtos como o açúcar, o álcool combustível e a bioeletricidade. A bioeletricidade é a energia elétrica gerada a partir da queima do bagaço de cana-de-açúcar. Assim, o bagaço é uma importante biomassa para uso industrial responsável por mover as usinas e ser comercializada como eletricidade. Apesar do bagaço de cana ter um papel muito importante na matriz energética nacional, normalmente essa biomassa é conduzida às caldeiras com alto teor de umidade, acarretando em perda de eficiência no processo de cogeração. Este trabalho propõe o uso de concentrador solar para a secagem do bagaço de cana-de-açúcar, a fim de aumentar a eficiência de cogeração. Para tanto, um concentrador solar de 1 m2 foi utilizado para aquecer um forno ventilado. A massa, a temperatura interna, a temperatura externa e a potência solar foram medidas. Os resultados mostram que o teor de umidade do bagaço industrial é de 42,72%. Os melhores resultados mostraram que é possível remover 82% da umidade inicial de 100 g de bagaço de cana-de-açúcar após 45 minutos de exposição ao sol

    Obtaining plasticized starch and microfibrillated cellulose from oil palm empty fruit bunches: preparation and properties of the pure materials and their composites.

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    Abstract: Starch and celluloses are biodegradable resources of great importance in terms of marketing. These biopolymers can be used to generate films with interesting mechanical, optical, and thermal properties, which can substitute for plastic films in certain applications, e.g., packaging materials. This study describes the preparation of pure plasticized starch films, prepared from soluble starch and glycerol, and the preparation of microfibrillated cellulose films from oil palm empty fruit bunches fabricated via casting. Composites made of plasticized starch were also prepared with microfibrillated cellulose added in 10% increments. The density, color difference, opacity, morphology, water activity, water affinity, and thermal and mechanical characteristics of the films were investigated. Plasticized starch is a translucent material with contact transparency; it is fragile and has relatively high water and glycerol contents. The thermogravimetric analysis of materials displayed up to four stages of weight loss related to water evaporation, glycerol, starch, and cellulose thermal degradation. As a consequence, the materials with higher cellulose content exhibited better thermal resistance. The composites with 90% of microfibrillated cellulose resulted in increased tensile strength when compared to the pure materials. The pure microfibrillated cellulose presented the highest values of Young modulus. The addition of plasticized starch to microfibrillated cellulose improved the maximum strain of the composites

    Isolamento e identificação de linhagens de Trichoderma em amostras de solos de cultivos de alho e cebola.

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    bitstream/item/170359/1/FINAL-boletim-de-pesquisa-e-desenvolvimento-330.pdf(Embrapa Recursos Genéticos e Biotecnologia. Boletim de Pesquisa e Desenvolvimento, 330
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