Alocação de biomassa de Brachiaria subquadripara sob diferentes concentrações de N, P e K

O presente trabalho objetivou avaliar a alocação de biomassa em plantas de Brachiaria subquadripara em função de diferentes concentrações de N, P e K em solução nutritiva. O delineamento experimental utilizado foi inteiramente casualizado, com seis repetições, e os tratamentos constituíram-se de cinco níveis de N, P e K (0, 25, 50, 75 e 100% da concentração na solução-base) durante cinco épocas (intervalos de sete dias). A solução-base utilizada refere-se à diluição de 20% da solução nutritiva para culturas agrícolas. A ausência de N propiciou maior alocação de biomassa em raízes do que em colmos até a quarta semana (28 DAT). A adição de 25 e 75% de fósforo na solução condicionou acréscimos de biomassa de 6,6 e 5,8%, respectivamente, em relação à ausência de fósforo. em condições de deficiência de potássio, as plantas apresentaram tendência a manter constante a proporção de colmos e raízes, porém decresceu a produção de folhas com a idade da planta.

Recuperação de solos degradados na exploração mineral de cassiterita: biomassa microbiana e atividade da desidrogenase

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

Metodologia para produção de Metarhizium anisopliae (METSCH.) sorokin em cultivo submerso: esporulação da biomassa, efeito da concentração de açúcar e custo do inoculant

Desenvolveram-se um método de cultivo e um meio de cultura para produção massal do fungo Metarhizium anisopliae (Metsch.) Sorokin, 1883, com maior pureza e concentração de conídios. Este método envolveu o cultivo submerso da linhagem M-61 do entomopatógeno em meio líquido de arroz parboilizado, extrato de levedura, extrato do percevejo da soja (Nezara viridula (L., 1758) Hemiptera, Pentatomidae), sob seis diferentes níveis de concentração de açúcar (0, 2, 4, 6, 8, 10g l-1), além do meio convencional sólido de arroz em grão. As biomassas obtidas foram separadas através de tela de nylon (63 mesh) e dispostas em estufa para a esporulação. Os efeitos dos tratamentos foram avaliados pelos parâmetros pesos fresco e seco do micélio, número de conídios por grama de substrato, viabilidade e patogenicidade dos conídios sobre o percevejo. Observou-se que 2.0g l-1 de açúcar em meio de cultura de extrato de N. viridula produziu o dobro do número de conídios por grama de substrato em relação à concentração de 10.0g l-1, a um custo 51 vezes inferior ao obtido no processo convencional de produção do fungo. A viabilidade não foi afetada nos diferentes meios utilizados. Não ocorreram diferenças significativas na patogenicidade em função dos meios de cultura e métodos de cultivo.

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.

Comparação de métodos para determinar biomassa na região amazônica

The aboveground biomass content of a region can be estimated by either direct or indirect methods. Direct methods correspond to the biomass content determination with scales and extrapolation of results to larger areas. It is a destructive and very laborious procedure. Indirect methods utilize formulas whose entrance parameters are obtained from forest inventories. Forest inventories are made with the purpose to plan exploration and land use and the inventory data are frequently not suitable for biomass estimation. Problems with both methods increase in the Amazon region, where little information is available on forest biomass. The objective of this paper is to establish, by comparing the application of the indirect and direct methods in the determination of the biomass, the more appropriate indirect formulation to represent the characteristic vegetation of a region in the amazonian forest. A 0.2 hectare area was chosen, which was part of a major forest clearing experiment conducted in Tomé Açu, a town located 250 km south of Belém, the capital of the Brazilian state of Pará. The entire biomass in the area was weighted with scales during the three weeks that followed the cut of the forest in July 1994. A detailed inventory was carried out in the area and then the indirect method was applied in the data. Seven different formulas for determining biomass were used. Comparison of the data of real mass and the mass obtained through the application of the seven formulas indicated that the more suitable for the region is given by FW = α · φβ · Hγ, where FW is total fresh weight (kg), φ is the diameter at breast height (cm), H is the total height of the tree and α, β and γ are regression coefficients (equal to 0.026, 1.529 and 1.747, respectively).

Reguladores vegetais na produção de biomassa e teor de óleos essenciais em Cymbopogon citratus (DC.) Stapf, em diferentes épocas do ano

The purpose of the present research was to evaluate the effect of plant growth regulators in biomass production and essential oil yield content in lemongrass (Cymbopogon citratus (DC.) Stapf), in different seasons. The experiment was conducted on São Manuel Experimental Farm, Faculdade de Ciências Agronômicas, UNESP - Botucatu. Which plants were randomly assigned into blocks to treatments with three repetitions. The treatments consisted of GA3 (50 and 100 mg L-1); Ethrel (100 and 200 mg L-1); CCC (500 and 1000 mg L-1); Alar 85 (1000 and 2000 mg L-1); Accel (20 and 40 mg 0L-1) and control. Four applications of plant growth regulators were realized every three months. After 40 days of each foliar spray, the plants were cut to determine the fresh weight and essential oil yield. The application of plant growth regulators did not increase the biomass production, showing difference among collect periods when the major production was detected at the fourth collect (summer). The greatest essential oil yield was found at the second collect (winter). In the present study, the used concentrations of plant growth regulators did not increase biomass neither essential oil yield.

Importância de Yersinia enterocolitica em microbiologia médica

Y. enterocolitica is a human invasive enteropathogen which causes a number of intestinal and extraintestinal clinical symptoms of various degrees of severity, ranging from mild gastroenteritis to mesenteric lymphadenitis, which mimics appendicitis and in rare cases can evolve to septicemia. Infection by Y. enterocolitica can also lead to post-infection immunological sequelae including arthritis, erythema nodosum and glomerulonephritis. Pathogenic Y. enterocolitica strains have traditionally been linked to specific biotypes and serogroups and associated to a variety of phenotypic characteristics related to virulence. Molecular genetics studies have pointed to the importance of the pYV virulence plasmid, which encodes various virulence genes, as well that of specific chromosomal virulence genes, in determining the pathogenesis of this bacterium. Intestinal infections by Y. enterocolitica are mostly self-limiting and usually do not need an antibiotic treatment. The occurrence of this microorganism is not as frequently described in Brazil as it is in other countries, such as Japan, USA and many European countries. This review focuses on the general characteristics, pathogenesis, clinical symptoms, virulence characteristics, treatment and antibiotic susceptibility of Yersinia enterocolitica strains isolated in Brazil and around the world.

Efeito de níveis de fósforo no crescimento inicial, biomassa e atividade in vivo da fosfatase ácida em Lychnophora ericoides Mart

The effect of phosphorus levels on seedling growth, dry and fresh matter production, and in vivo acid phosphatase activity was studied in Lychnophora ericoides cultivated during 130 days after transplanting in a greenhouse. Experimental design was completely randomized, with four P 2O 5 levels (0; 40; 80; 160 mg dm -3 as triple superphosphate) and five replicates of four plants each. The used soil was dystrophic acid dark red latosol. Lychnophora ericoides is responsive to phosphate fertilization with modification in daily relative growth rate, dry matter production and distribution among the plant parts. Acid phosphatase activity had significant and negative correlation with total, leaf and stem dry matter production, as well as with P levels accumulated in the leaf tissue. On the other hand, acid phosphatase activity had significant and positive correlation with root/shoot ratio.

Efeitos do extrato de parede de levedura em dieta seca sobre a Microbiologia, ácidos graxos de cadeia curta e redução do odor das fezes de gatos adultos

The aim of this study was to evaluate the effects of yeast cell wall extract (YCW) in dry diet on the fecal microbiota, concentration of short-chain fatty acids (SCFA) and on the odor reduction of cats feces. We used 20 animals of both sexes, randomly assigned to four treatments and five repetitions totaling 20 experimental units: 1) dry commercial diet (control); 2) control + 0.2%, 3) control + 0.4%, and 4) control + 0.6% of YCW in dry matter. Enterobacteriaceae and lactic acid bacteria, fecal concentration of acetic, propionic and butyric acids, ammonia nitrogen and sensory panel were performed. There were no significant differences (p> 0.05) for bacterial counts and the concentration of SCFA and ammonia, but in sensory panel a reduction in the odor of feces could be noted with the use of 0.2% of YCW. We concluded that the addition of up to 0.6% YCW had no effect on the microbiology and the concentration of fatty acids, but there is potential for its use as an additive because of the improvement in the odor of feces. However, further studies are needed to understand the mechanisms of action and the effects of prebiotics for domestic cats.

Nitrogênio e idade de corte na qualidade da biomassa de capimelefante para fins agroenergéticos cultivado em Latossolo

Nowadays one of the major challenge for research is the production of alternative agrifuels energy material derived from plant biomass. Allied to this, the proper management of nitrogen, becomes fundamental for productivity gains and improvement in quality of elephant grass biomass. Thus, the objective was to evaluate the effect of nitrogen fertilization and plant age effect on the quality of elephant grass biomass for energy purposes. The experiment was performed with genotype Paraíso, grown in a dystrophic Oxisol in the southern state of Tocantins. The design was randomized blocks with subdivided plots, situating plots as nitrogen rates (0, 50, 100 and 150 kg ha-1) and the subplots cutting age (120, 150 and 180 days after planting ) four replicates. We evaluated the relationship carbon/nitrogen (C:N) and leaf/stem (L:S), levels of neutral detergent fiber (NDF) and ash contents in dry biomass produced. The application of nitrogen increased by 12% to C:N ratio of the plant. The advanced age of cut forage was increased 9% in the C:N plant, however, decreased by 12 and 14% levels of ash produced in the stem and leaves, respectively. The production of elephant grass for agrifuels is feasible with management system proposed, quality characteristics desirable, such as high C:N ratio, above 40% and higt fiber content, above 50%.

Acúmulo de biomassa em variedades de cana-de-açúcar inoculadas com diferentes estirpes de bactérias diazotróficas

The objective of this study was to evaluate the contribution of inoculation with diazotrophs, applied both individually and in combination, in commercial varieties of sugarcane. The experiment was carried out at the experimental grounds of Embrapa Agrobiologia, in Seropédica, Rio de Janeiro, Brazil. The experimental design was of randomised blocks, with sub-divided plots and six replications. Six varieties of sugarcane with six treatments were used: control, control with nitrogen, inoculation of the individual strains: BR 11512, BR 11724 and BR 11411, in addition to inoculation with a cocktail consisting of five strains of diazotrophs. Differences were observed between varieties and between treatments, and an interaction observed between the treatments and varieties. For all the parameters evaluated, no response was observed in the sugarcane varieties RB855536 and RB92606. In the variety RB918639, the only difference was in the accumulation of green biomass. No difference was observed between the treatments for total nitrogen accumulation. The most responsive variety to inoculation was RB867515, differing in the accumulation of fresh and dry biomass. This study showed that inoculation promotes the accumulation of biomass, the contribution being different for the varieties and strains of bacteria, suggesting an interaction between the factors studied. The variety RB867515 is promising for use in studies of inoculation with diazotrophs.

Efeito residual de fontes de fósforo nos atributos químicos do solo, nutrição e produtividade de biomassa da cana-de-açúcar

In tropical regions, the residual effect of phosphate fertilizer source is of crucial importance. This study aimed to evaluate the effects of application of P sources in chemical properties of soil, nutrition and productivity of sugarcane plant and during the first and second ratoon. The sources of P applied in furrows at planting were, triple superphosphate, Arad phosphate, bone meal (100 kg ha-1 P2O5 total) and a control without P, the varieties of sugarcane studied were IAC86-2480 and SP79-1011. A randomized block design in a 4 × 2 factorial was used, with four replications. The study was conducted in the municipality of Alta Floresta-MT, Brazil, in Typic Hapludox. After each cutting, in soil P content, pH and Ca were evaluated. In the plant, the production of green and dry matter of shoots, the concentration of P in the biomass harvested, the export of P and agronomic efficiency of the sources of P were determined. The bone meal had a higher agronomic efficiency resulted in greater accumulation and export of P by crop, higher content of available Ca and P and increase soil pH. The Arad reactive phosphate increased its agronomic efficiency between crop cycles.

Produção de etanol a partir de mosto hidrolisado hemicelulósico de ponta e palha de cana-de-açúcar

Pós-graduação em Microbiologia Agropecuária - FCAV

Métodos híbridos de pontos interiores e de programação inteira 0-1 para problemas de custo de colheita da cana-de-açúcar e de custo de coleta e geração de energia relacionados à sua biomassa

Pós-graduação em Engenharia Elétrica - FEB