Biodegradação de glifosato pela microbiota de solos cultivados com macieira.

Resumo: O glifosato é um herbicida sistêmico, pós-emergente, não seletivo do grupo dos organofosforados, sendo amplamente usado em pomares de macieira no sul do Brasil, podendo causar consequências negativas para microrganismos benéficos do solo. O objetivo deste trabalho foi avaliar a capacidade de biodegradação do glifosato pela microbiota de solos de pomares de macieira, com diferentes históricos de aplicação do produto. Para isso, amostras de solos da região de Vacaria, RS, foram utilizadas, cuja biodegradação do glifosato foi avaliada monitorando a liberação de CO2 pelos microrganismos durante 32 dias, bem como quantificando os resíduos de glifosato e seu metabólito, o ácido aminometilfosfônico (AMPA), no início e no final do período pela extração seguidade análise por cromatografia líquida de alta eficiência. Os resultados evidenciaram que houve degradação do glifosato pelos microrganismos edáficos durante o período avaliado com formação do metabólito AMPA. O glifosato diminuiu o número de bactérias do solo, porém favoreceu o aumento da atividade microbiana. As bactérias presentes nos solos com histórico de menor tempo de aplicação do herbicida apresentaram maior capacidade de degradação do produto, quando comparadas àquelas existentes em solos com maior período de aplicação de glifosato. Abstract: Glyphosate is a systemic post-emergent herbicide of the non-selective organophosphate group widely used in apple orchards in the South of Brazil. It may have adverse effects on beneficial soil microorganisms. The aim of this study was to evaluate the biodegradability of glyphosate by soil microbiota in apple orchards with different histories of application of the product. For that purpose, soil samples from the region of Vacaria, Rio Grande do Sul, were used, with the biodegradation of glyphosate being evaluated by monitoring the release of CO 2 by microorganisms over 32 days, as well as quantifying the residues of glyphosate and its metabolite, aminomethylphosphonic acid (AMPA), at the beginning and end of the period through extraction followed by analysis by high performance liquid chromatography (HPLC). The results showed that there was glyphosate degradation by soil microorganisms during the period evaluated, with formation of the metabolite AMPA. Glyphosate decreased the number of soil bacteria, but favored increased microbial activity. The bacteria present in soils with lower herbicide exposure showed more degradability of the product when compared to those found in soils with a greater period of glyphosate application

Over-Expression of a Cytochrome P450 Is Associated with Resistance to Pyriproxyfen in the Greenhouse Whitefly Trialeurodes vaporariorum

Copyright: 2012 Karatolos et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.Background: The juvenile hormone mimic, pyriproxyfen is a suppressor of insect embryogenesis and development, and is effective at controlling pests such as the greenhouse whitefly Trialeurodes vaporariorum (Westwood) which are resistant to other chemical classes of insecticides. Although there are reports of insects evolving resistance to pyriproxyfen, the underlying resistance mechanism(s) are poorly understood. Results: Bioassays against eggs of a German (TV8) population of T. vaporariorum revealed a moderate level (21-fold) of resistance to pyriproxyfen. This is the first time that pyriproxyfen resistance has been confirmed in this species. Sequential selection of TV8 rapidly generated a strain (TV8pyrsel) displaying a much higher resistance ratio (>4000-fold). The enzyme inhibitor piperonyl butoxide (PBO) suppressed this increased resistance, indicating that it was primarily mediated via metabolic detoxification. Microarray analysis identified a number of significantly over-expressed genes in TV8pyrsel as candidates for a role in resistance including cytochrome-P450 dependent monooxygenases (P450s). Quantitative PCR highlighted a single P450 gene (CYP4G61) that was highly over-expressed (81.7-fold) in TV8pyrsel. Conclusion: Over-expression of a single cytochrome P450 gene (CYP4G61) has emerged as a strong candidate for causing the enhanced resistance phenotype. Further work is needed to confirm the role of the encoded P450 enzyme CYP4G61 in detoxifying pyriproxyfen.Peer reviewedFinal Published versio

Chemical composition and antigenotoxic properties of Lippia alba essential oils

The present work evaluated the chemical composition and the DNA protective effect of the essential oils (EOs) from Lippia alba against bleomycin-induced genotoxicity. EO constituents were determined by Gas Chromatography/Mass Spectrometric (GC-MS) analysis. The major compounds encountered being citral (33% geranial and 25% neral), geraniol (7%) and trans-β-caryophyllene (7%) for L. alba specimen COL512077, and carvone (38%), limonene (33%) and bicyclosesquiphellandrene (8%) for the other, COL512078. The genotoxicity and antigenotoxicity of EO and the compounds citral, carvone and limonene, were assayed using the SOS Chromotest in Escherichia coli. The EOs were not genotoxic in the SOS chromotest, but one of the major compound (limonene) showed genotoxicity at doses between 97 and 1549 mM. Both EOs protected bacterial cells against bleomycin-induced genotoxicity. Antigenotoxicity in the two L. alba chemotypes was related to the major compounds, citral and carvone, respectively. The results were discussed in relation to the chemopreventive potential of L. alba EOs and its major compounds

Biodegradação por Glifosato por bactérias isoladas de solo cultivados com macieiras com diferentes históricos de aplicação deste herbicida.

Dissertação (Mestrado em Microbiologia Agrícola e do Ambiente) - Universidade Federal do Rio Grande do Sul, Porto Alegre. Orientado por Marco Antônio Zácchia Ayub, UFRGS; e co-orientado por Gilmar Ribeiro Nachtigall, CNPUV

Preparation and thermal decomposition of solid state chelates of ethylenediaminetetraacetic acid with manganese

Solid state of general formula H2[Mn(EDTA)].3,5H2O, where EDTA is ethylenediaminetetraacetate, were prepared. Thermogravimetry derivative thermogravimetry (TG-DTG), differential scanning calorimetry (DSC) and other methods of analysis have been used to characterize and to study the thermal stability and thermal decomposition of this complex

http://www.seasinop.com.br/revista/index.php?journal=SEA&page=article&op=view&path%5B%5D=221&path%5B%5D=pdf_93

The bar soap is a cosmetic personal care product most consumed in the world. The incorporation of actives to these products provides greater refinement to the formulation. Oils are incorporated in order to increase the moisturize and hydration of the skin. Stability tests are conducted to demonstrate the product's behavior during its period of validity and are essential when there is development of new formulations. The objective of this work was to produce bar soaps containing pequi oil and evaluate its stability through physicochemical testing. They developed three primary formulations with different pequi oil concentrations (1, 3 and 5% w/w), which were evaluated for strength and absorption to water, durability, melting, foaming, crack formation and pH . The best results were obtained with the incorporation of 3% (w/w) of oil. After determination of the optimal concentration of oil, a new formulation was developed containing 3% of pequi oil and the stability tests were remade. It was found that the soaps showed good stability. Thus, it can be shown that the pequi oil can be used for preparation of bar soaps and that they have stability within the parameters studie