A leukocyte cryopreservation technique for cytogenetic studies

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

Antifungal activity of extracts from Brazilian Cerrado plants on Colletotrichum gloeosporioides and Corynespora cassiicola

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Solubilização de fosfatos de rocha por Aspergillus niger em diferentes tipos de vinhaça

Aspergillus niger was inoculated into flasks containing mixed of different origins and fluorapatite as a source of phosphorus, or alternatively rock phosphates of different compositions. There was no difference in fungal growth or fluorapatite solubilization when sterilized or unsterilized vinasse was used. Total and soluble solid content was at least two times higher in 65/35 vinasse than in 10/1 vinasse. The higher total sugar content causing higher titratable acidity levels, or the lower fungal growth, may possibly have favored the greater accumulation of soluble phosphate in 10/1 than in 65/10 vinasse. No appreciable differences in residual soluble phosphate levels were detected with increasing fluorapatite concentrations. Rock phosphates of different origins and with different phosphorus concentrations affected the solubilizing ability of the fungus. Whereas crude concentrated apatite phosphorus favored the greatest accumulation of soluble phosphate in the culture medium (1.08 mg/ml), the highest solubilization (72% total phosphate) was achieved with Patos de Minas material obtained from the first crushing.

Comparação de dois métodos de extração de Xanthomonas campestris pv. phaseoli em sementes de feijoeiro

The objective of this research was to evaluate the effectiveness of the extraction of Xanthomonas campestris pv. phaseoli from naturally infected dry bean seeds. Extraction methods tested included soaking whole seeds in sterilized saline phosphate buffer and crushing seeds after soaking in sterilized saline phosphate buffer. The bacterium was isolated on a semiselective agar medium. The seed crushing method was found to be more effective. The bacterium strains isolated were pathogenic to bean leaves, reacted with X. campestris pv. phaseoli antiserum, and had morphological and physiological/biochemical characteristics typical of the X. campestris pv. phaseoli.

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.

Fontes de carbono de baixo custo para a produção de xilanase termoestável por aspergillus niger

A strain of the flamentous fungus Aspergillus niger was isolated and shown to possess extracellular xylanolytic activity. These enzymes have biotechnological potential and can be employed in various industries. This fungus produced its highest xylanase activity in a medium made up of 0.1% CaCO3, 0.5% NaCl, 0.1% NH4Cl, 0.5% corn steep liquor and 1% carbon source, at pH 8.0. A low-cost hemicellulose residue (powdered corncob) proved to be an excellent inducer of the A. niger xylanolytic complex. Filtration of the crude culture medium with suspended kaolin was ideal for to clarify the extract and led to partial purifcation of the xylanolytic activity. The apparent molecular mass of the xylanase was about 32.3 kDa. Maximum enzyme activity occurred at pH 5.0 and 55-60oC. Apparent Km was 10.41 ± 0.282 mg/mL and Vmax was 3.32 ± 0.053 U/mg protein, with birchwood xylan as the substrate. Activation energy was 4.55 kcal/mol and half-life of the crude enzyme at 60oC was 30 minutes. Addition of 2% glucose to the culture medium supplemented with xylan repressed xylanase production, but in the presence of xylose the enzyme production was not affected.

Avaliação in vitro de diferentes métodos de análises de fungitoxicidade de óleos essenciais

Environmental problems caused by synthetic fungicides have increased the search for alternative methods of control of plant diseases. The objective was to evaluate the effect of essential oil of citronella grass, on the fungus Rhizoctonia solani, in different methods of in vitro fungitoxicity. We used a randomized design in a factorial design with four replications, where the factors were composed of four methods for assessing the in vitro fungitoxicity of the essential oil of citronella grass (essential oil diluted in Tween 80 (0.5%) and embedded in the culture medium PDA (potato dextrose agar) still melting, essential oil diluted in Tween 80 (0.5%) and distributed on the surface of the PDA; oil essential diluted in Tween 80 (0.5%) and distributed on filter paper attached to the inner surface of the lid of the Petri dish, pure essential oil and distributed on the surface of the culture medium, and control) and five evaluation periods (2, 4, 6, 8 and 10 days of incubation). Was used 0.25μL mL-1 of citronella oil in all treatments. Of the treatments evaluated the use of pure oil distributed on the surface of the culture medium was more effective in reducing the mycelial diameter in all evaluations. In this method the rate of mycelial growth was 9,02 mm day-1, reaching in last evaluation 79,77 mm.

Sensibilidade de stenocarpella macrospora a fungicidas

The application of fungicides in the aerial organs is control strategy to macrospora spot caused by fungus Stenocarpella macrospora. The objective of this study was to determine the sensitivity of S. macrospora to fungicides by inhibition of mycelial growth (MG) and conidial germination (CG). It was eval uated 12 fungicides belonging to the chemical groups of the benzimidazoles, triazoles and strobilurins, six concentrations and two isolates of the fungus (SC and MT). The fungicides were diluted in sterile distilled water and added to the culture medium of potato dextrose agar (mycelium) and water-agar (spore) after sterilization. The percentage of inhibition of MC and CG was calculed in comparison with control, estimating of 50% inhibitory concentration (IC50). The fungicides tested were effective in inhibiting the MC. The IC50 was less than 1 ppm for all fungicides. There was no difference between isolates. The inhibition of CG had higher fungitoxicity strobilurins, and the IC50 was between 0.0035 and 0.03 ppm, and the isolated SC showed the higher sensitivity to the fungicides. The IC50 values obtained for fungicides and specific S. macrospora will be useful in monitoring the sensitivity of the fungus, especially in regions with intense demand for fungicides in corn.

Controle de mofo-cinzento (amphobotrys ricini) da mamoneira (ricinus communis l.) por métodos químico, biológico e com óleos essenciais

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Esterilização de materiais termossensíveis através de aplicação de plasma gerado por descarga com barreira dielétrica (DBD)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Efeito α-tomatina na proliferação celular, apoptose e expressão de RNAm dos genes APC, Ciclina A2, Catenina, CASP9, BAK, BAX e BCL-XL em células HT29

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Ação alelopática de saxitoxinas e microcistinas em cianobactérias e microalgas verdes em condições controladas

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

Associação de enterococcus faecalis, candida albicans e escherichia coli em canais radiculares e avaliação dos efeitos de extratos naturais sobre os microrganismos e endotoxinas

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Desenvolvimento de métodos de cultivo de Gluconacetobacter xylinus para obtenção de compósitos à base de celulose bacteriana e colágeno tipo I adicionado in situ

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

Influência das condições de cultivo e métodos de extração na produção de metabólitos antioxidantes por fungos isolados do litoral paulista

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)