Interação de microorganismos na solubilização de fósforo e potássio de rochas para produção de biofertilizantes

he present model of agriculture is based on intensive use of industrial inputs, due to its rapid response, but it brings harmful consequences to the environment, and it is necessary the use of modern inputs. And an alternative is the use of rock biofertilizers in agriculture, a product easy to use, with higher residual effect and does not harm the environment. The objective of study was to evaluate the inoculation and co-inoculation of different microorganisms in the solubilization of rock phosphate and potash ground microbial evaluating the best performance in the production of biofertilizers comparing with rocks pure in soil chemical properties and, verify effect of inoculation of the bacterium Paenibacillus polymyxa in the absorption of minerals dissolved in the development of cowpea (Vigna unguiculata [L.] Walp.). The first bioassay was conducted in Laboratory (UFRN) for 72 days in Petri dishes, where the rock powder was increased by 10% and sulfur co-inoculated and inoculated with bacterial suspension of Paenibacillus polymyxa grown in medium tryptone soy broth, Ralstonia solanacearum in medium Kelman, Cromobacterium violaceum in medium Luria-Bertani and Acidithiobacillus thiooxidans in medium Tuovinen and Kelly,and fungi Trichoderma humatum and Penicillium fellutanum in malt extract. Every 12 days, samples were removed in order to build up the release curve of minerals. The second bioassay was conducted in a greenhouse of the Agricultural Research Corporation of Rio Grande do Norte in experimental delineation in randomized block designs, was used 10 kg of an Yellow Argissolo Dystrophic per pot with the addition of treatments super phosphate simple (SS), potassium chloride (KCl), pure rock, biofertilizers in doses 40, 70, 100 and 200% of the recommendation for SS and KCl, and a control, or not inoculated with bacteria P. polymyxa. Were used seeds of cowpea BRS Potiguar and co-inoculated with the bacterial suspension of Bradyrhizobium japonicum and P. polymyxa. The first crop was harvested 45 days after planting, were evaluated in the dry matter (ADM), macronutrients (N, P, K, Ca, Mg) and micronutrients (Zn, Fe, Mn) in ADM. And the second at 75 days assessing levels of macro end micronutrients in plants and soil, and the maximum adsorption capacity of P in soil. The results showed synergism in co-inoculations with P. polymyxa+R. solanacearum and, P. polymyxa+C. violaceum solubilizations providing higher P and K, respectively, and better solubilization time at 36 days. The pH was lower in biofertilizers higher doses, but there was better with their addition to P at the highest dose. Significant reduction of maximum adsorption capacity of phosphorus with increasing dose of biofertilizer. For K and Ca was better with SS+KCl, and Mg to pure rock. There was an effect of fertilization on the absorption, with better results for P, K and ADM with SS+KCL, and N, Ca and Mg for biofertilizers. Generally, the P. polymyxa not influence the absorption of the elements in the plant. In treatments with the uninoculated P. polymyxa chemical fertilizer had an average significantly higher for weight and number of grains. And in the presence of the bacteria, biofertilizers and chemical fertilizers had positive values in relation to rock and control. The data show that the rocks and biofertilizers could meet the need of nutrients the plants revealed as potential for sustainable agriculture

Improvement of the oral praziquantel anthelmintic effect by cyclodextrin complexation

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

Computational analysis and physico-chemical characterization of an inclusion compound between praziquantel and methyl-beta-cyclodextrin for use as an alternative in the treatment of schistosomiasis

Schistosomiasis is still an endemic disease in many regions, with 250 million people infected with Schistosoma and about 500,000 deaths per year. Praziquantel (PZQ) is the drug of choice for schistosomiasis treatment, however it is classified as Class II in the Biopharmaceutics Classification System, as its low solubility hinders its performance in biological systems. The use of cyclodextrins is a useful tool to increase the solubility and bioavailability of drugs. The aim of this work was to prepare an inclusion compound of PZQ and methyl-beta-cyclodextrin (MeCD), perform its physico-chemical characterization, and explore its in vitro cytotoxicity. SEM showed a change of the morphological characteristics of PZQ:MeCD crystals, and IR data supported this finding, with changes after interaction with MeCD including effects on the C-H of the aromatic ring, observed at 758 cm(-1). Differential scanning calorimetry measurements revealed that complexation occurred in a 1:1 molar ratio, as evidenced by the lack of a PZQ transition temperature after inclusion into the MeCD cavity. In solution, the PZQ UV spectrum profile in the presence of MeCD was comparable to the PZQ spectrum in a hydrophobic solvent. Phase solubility diagrams showed that there was a 5.5-fold increase in PZQ solubility, and were indicative of a type A(L) isotherm, that was used to determine an association constant (K(a)) of 140.8 M(-1). No cytotoxicity of the PZQ:MeCD inclusion compound was observed in tests using 3T3 cells. The results suggest that the association of PZQ with MeCD could be a good alternative for the treatment of schistosomiasis.

Alterações nas concentrações das SRAT, conteúdo de GSH e atividade da CAT em pacientes com esquistossomose aguda

Schistosomiasis is an ancient disease caused by helminth Schistosoma mansoni and is a public health problem in Brazil. The granulomatous lesion, typical of the disease, associates itself with increase in the oxidative damage through the generation of free radicals. The aim of this work was to evaluate the occurrence of changes in parameters oxidant / antioxidant that are part of the human defense system, and observe whether they would cause oxidative stress in subjects with schistosomiasis. Moreover, correlating with some biochemical and hematological parameters. Two groups were selected for study, consisting of individuals of both sexes, aged between 16 and 30 years. A control group, formed by individuals without schistosomiasis (n = 30) and a test group, formed by individuals with schistosomiasis (n = 30). The evaluation of lipid peroxidation in plasma was performed by determination of malondialdehyde and antioxidant defense by the quantification of reduced glutathione and catalase activity. For the parameters that assess oxidative stress, the results showed a decrease in the content of reduced glutathione and no change in the activity of catalase, with an increase in the value of malondialdehyde. Therefore, the data found suggest the occurrence of oxidative stress in subjects with schistosomiasis. Of the parameters that assess hepatic function, only levels of aspartate aminotransferase have been high, while there was a decrease of bilirubine. There was a significant change in the lipid profile (p <0.5), however with regard to the renal function of patients, there was a decrease in creatinine. The assessment hematological, made through hemogram and the quantification of hemoglobin, shows increase of eosinophils individuals in the group test, which can be related to the presence of the parasite. The amendments suggest the involvement of oxidative stress in the pathophysiology of this disease

Genetic differences between strains of Biomphalaria glabrata (Planorbidae) that are susceptible and unsusceptible to schistosomiasis

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

Development of praziquantel-loaded PLGA nanoparticles and evaluation of intestinal permeation by the everted gut Sac model

Praziquantel has been shown to be highly effective against all known species of Schistosoma infecting humans. Spherical nanoparticles made of poly(D,L-lactide-co-glycolide) acid with controlled size were designed as drug carriers. Praziquantel, a hydrophobic drug, was entrapped into the polymeric nanoparticles with 30% (w/w) of theoretical loading. The nanoparticles size was approximately of 350 nm with 66% of encapsulation efficiency. The everted gut sac model shows to be efficient to evaluate the drug permeation through the intestinal membrane. The results show that free praziquantel presents 4-fold times more permeation than praziquantel-loaded PLGA nanoparticles and physical mixture. For this drug, in special, this result can be interesting, since the nanoparticulate system can behave as a drug reservoir and/or to have a more localized effect in intestinal membrane for a prolonged period of time, since great amounts of parasites can be usually found in the mesenteric veins.

PLGA nanoparticles containing praziquantel: effect of formulation variables on size distribution

Praziquantel has been shown to be highly effective against all known species of Schistosoma infecting humans. Spherical nanoparticulate drug carriers made of poly(D,L-lactide-co-glycolide) acid with controlled size were designed. Praziquantel, a hydrophobic molecule, was entrapped into the nanoparticles with theoretical loading varying from 10 to 30% (w/w). This investigates the effects of some process variables on the size distribution of nanoparticles prepared by emulsion-solvent evaporation method. The results show that sonication time, PLGA and drug amounts, PVA concentration, ratio between aqueous and organic phases, and the method of solvent evaporation have a significant influence on size distribution of the nanoparticles. (C) 2004 Elsevier B.V. All rights reserved.

Improvement of antischistosomal activity of praziquantel by incorporation into phosphatidylcholine-containing liposomes

Praziquantel (PZQ) is effective against all known species of Schistosomes that infect humans. The failure of mass treatment of schistosomiasis has been attributed to the fact that therapy is not sufficiently long-lasting. This effect may be due to the low bioavailability of PZQ that has a low hydrosolubility and fast metabolism. Liposomes have been used to prolong drug levels. reduce the side effects, direct drugs to specific sites and increase bioavailability after administration. The aim of this work was to study the effect of phosphatidylcholine (PC)-containing liposomes to vehiculate PZQ to improve the treatment of schistosomiasis. The in vitro Study was carried out using Schistosoma mansoni parasites recovered by perfusion from the hepatic portal system of infected mice. Suspensions of liposomes with PZQ and free PZQ were administered p.o. in mice after 14 days of infection. The effect of both preparations in vitro on S. mansoni culture was similar. In the in vivo test, PZQ-liposomes caused a decrease in amounts of eggs and parasites. Liposomes improve the antischistosomal activity of praziquantel. This can be used as a starting point to investigate alternative administration routes or dosage forms and to examine the mechanism of intestinal absorption of PRZ © 2005 Elsevier B.V. All rights reserved.

Multidimensional cluster stability analysis from a Brazilian Bradyrhizobium sp RFLP/PCR data set

The taxonomy of the N(2)-fixing bacteria belonging to the genus Bradyrhizobium is still poorly refined, mainly due to conflicting results obtained by the analysis of the phenotypic and genotypic properties. This paper presents an application of a method aiming at the identification of possible new clusters within a Brazilian collection of 119 Bradryrhizobium strains showing phenotypic characteristics of B. japonicum and B. elkanii. The stability was studied as a function of the number of restriction enzymes used in the RFLP-PCR analysis of three ribosomal regions with three restriction enzymes per region. The method proposed here uses Clustering algorithms with distances calculated by average-linkage clustering. Introducing perturbations using sub-sampling techniques makes the stability analysis. The method showed efficacy in the grouping of the species B. japonicum and B. elkanii. Furthermore, two new clusters were clearly defined, indicating possible new species, and sub-clusters within each detected cluster. (C) 2008 Elsevier B.V. All rights reserved.

Bothrops moojeni myotoxin-II, a Lys49-phospholipase A(2) homologue: An example of function versatility of snake venom proteins

MjTX-II, a myotoxic phospholipase A(2) (PLA(2)) homologue from Bothrops moojeni venom, was functionally and structurally characterized. The MjTX-II characterization included: (i) functional characterization (antitumoral, antimicrobial and antiparasitic effects); (ii) effects of structural modifications by 4-bromophenacyl bromide (BPB), cyanogen bromide (CNBr), acetic anhydride and 2-nitrobenzenesulphonyl fluoride (NBSF); (iii) enzymatic characterization: inhibition by low molecular weight heparin and EDTA; and (iv) molecular characterization: cDNA sequence and molecular structure prediction. The results demonstrated that MjTX-II displayed antimicrobial activity by growth inhibition against Escherichia coli and Candida albicans, antitumoral activity against Erlich ascitic tumor (EAT), human breast adenocarcinoma (SK-BR-3) and human T leukemia cells (JURKAT) and antiparasitic effects against Schistosoma mansoni and Leishmania spp., which makes MjTX-II a promising molecular model for future therapeutic applications, as well as other multifunctional homologous Lys49-PLA(2)S or even derived peptides. This work provides useful insights into the structural determinants of the action of Lys49-PLA2 homologues and, together with additional strategies, supports the concept of the presence of others bioactive sites distinct from the catalytic site in snake venom myotoxic PLA(2)s. (c) 2005 Elsevier B.V. All rights reserved.

Avaliação de populações de possíveis rizobactérias em solos sob espécies florestais

Embora estudos recentes relatem a utilização de RCPC (Rizobactérias Promotoras de Crescimento de Plantas) no Brasil, raríssimos trabalhos avaliam a presença natural dessas espécies bacterianas no solo. O objetivo deste trabalho foi avaliar a ocorrência de RPCP em duas amostras de solo sob diferentes tipos de manejo, através da construção e do seqüenciamento de bibliotecas de DNA metagenômico. Utilizaram-se oligonucleotídeos específicos para amplificação da região hipervariável do espaço intergênico dos genes ribossomais 16S-23S de DNA extraído de diferentes solos, sob Eucalyptus sp. e sob mata. Os fragmentos obtidos foram inseridos em vetor e clonados. As bibliotecas geraram 495 clones, que foram seqüenciados e identificados através de comparações realizadas pelo software Blast. O solo sob Eucalyptus sp. apresentou maior número de RPCP do que sob mata. Os filos Actinobacteria e Proteobacteria eram maiores no solo sob Eucalyptus sp., estando o filo Firmicutes ausente no solo sob mata. Somente oito espécies diferentes de RPCP foram detectadas: Bacillus subtilis, Bacillus megaterium, Bradyrhizobium japonicum, Bradyrhizobium elkanii, Bradyrhizobium sp., Frankia sp., Pseudomonas fluorescens e Pseudomonas gladioli. O trabalho forneceu valiosos dados sobre a presença de RPCP em solos com espécies florestais e sua possível utilização em reflorestamentos, assim como para o melhor conhecimento desses microrganismos nos solos do Brasil.

TRATAMENTO DE SEMENTES DE ARROZ, TRIGO, FEIJÃO E SOJA COM UM PRODUTO FORMULADO À BASE DE CÉLULAS E DE METABÓLITOS DE Bacillus subtilis

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Sex Determination and Female Reproductive Development in the GenuSchistosoma: A Review

Os parasitas do gênero Schistosoma situam-se entre os primeiros metazoários que desenvolveram sexos separados, determinado cromossomicamente no ovo fertilizado. Apesar da ocorrência de cromossomos sexuais específicos, as fêmeas de Schistosoma não atingem a maturidade somática e sexual sem a presença dos machos. Na verdade, um dos aspectos mais controversos e, ao mesmo tempo, mais fascinantes, envolvendo o desenvolvimento sexual das fêmeas está em se desvendar a natureza do estímulo que controla e mantém tal processo. Muito embora a natureza do estímulo (físico ou químico) seja motivo de controvérsia, concordam os mais diferentes autores que o acasalamento é um requisito indispensável para que ocorra a maturação e migração das fêmeas para o sítio definitivo de permanência no sistema vascular do hospedeiro vertebrado. Admite-se, ainda, que o estímulo não é espécie-específico e, em alguns casos, nem mesmo gênero-específico. Não obstante a existência de um número considerável de artigos dedicados ao tema, não há um consenso sobre o processo (ou processos) que controla(m) o encontro de machos e fêmeas no sistema circulatório do hospedeiro vertebrado, bem como está por ser determinada a natureza do estímulo, oriundo dos machos, que controla e mantém o desenvolvimento somático e sexual das fêmeas. Ao longo dos anos os machos de Schistosoma têm sido considerados, por vezes pejorativamente, os irmãos, os músculos ou o fígado das fêmeas. em síntese, resta saber se a natureza do estímulo responsável pelo desenvolvimento das fêmas envolve a transferência de hormônios, nutrientes, a mera estimulação tátil ou a combinação de dois ou mais desses fatores

A LINE2 repetitive DNA sequence from the cichlid fish, Oreochromis niloticus: sequence analysis and chromosomal distribution

We report the cloning and characterization of a long interspersed nucleotide element (LINE) fi-om a cichlid fish, Oreochromis niloticus, and show the distribution of this element, called CiLINE2 for cichlid LINE2, in the chromosomes of this species. The identification of an open reading frame in CiLINE2 with amino acid sequence similarity to reverse transcriptases encoded by LINE-like elements in Caenorhabditis elegans, Platemys spixii, Schistosoma mansoni, Gallus gallus (CRI), Drosophila melanogaster (I factor), and Homo sapiens (LINE2), as well as the structure of the element, suggest it is a member of this family of non-long terminal repeat-containing retrotransposons. Search of a DNA sequence database identified sequences similar to CiLINE2 in four other fish species (Haplotaxodon microlepis, Oreochromis mossambicus, Pseudotropheus zebra, and Fugu rubripes). Southern blot hybridization experiments revealed the presence of sequences similar to CiLINE2 in all Tilapiini species analyzed from the genera Oreochromis, Tilapia, and Sarotherodon, and gave an estimated copy number of about 5500 for the haploid genome of O. niloticus. Fluorescent in situ hybridization showed that CiLINE2 sequences were organized in small clusters dispersed over all chromosomes of O. niloticus, with a higher concentration near chromosome ends. Furthermore the long arm of chromosome 1 was strikingly enriched with this sequence. The distribution of LINE2-related elements might underlie the difference in chromosome banding patterns observed between cold-blooded vertebrates and mammals.