The use of a copper solid amalgam electrode (CuSAE) for the analytical determination of triazine herbicides (atrazine and ametryne) instead of the conventional hanging mercury drop electrode (HMDE) is reported. The results obtained using electroanalytical methods utilizing each of these electrodes were also compared with those provided by the HPLC technique. The results indicated that the CuSAE electrode can be used to detect the herbicides studied, since the detection limits reached using the electrode (3.06 microg L-1 and 3.78 microg L-1 for atrazine and ametryne, respectively) are lower than the maximum values permitted by CONAMA (Brazilian National Council for the Environment) for wastewaters (50 microg L-1) and by the US EPA (Environmental Protection Agency of the United States) in natural water samples (10.00 microg L-1). An electroanalytical methodology employing CuSAE and square wave voltammetry (SWV) was successfully applied to the determination of atrazine and ametryne in natural water samples, yielding good recoveries (70.30%-79.40%). This indicates that the CuSAE provides a convenient substitute for the HMDE, particularly since the CuSAE minimizes the toxic waste residues produced by the use of mercury in HDME-based analyses.

Em Primeiro lugar agradeço à Deus por me dar disposição, força de vontade e saúde para realizar este trabalho. À Prof. Dra.Maria Teresa P. Gambardella, pela orientação e confiança desde o primeiro contato e pela credibilidade e apoio. Ao Dr. Evaldo L. Espíndola, pela credibilidade em mim depositada, que foi fundamental para minha vida em São Carlos. À Prof. Dra. Eny M. Vieira pelo incentivo, oportunidade oferecida e amizade. À Dra. Janete Brigante, pelo apoio à pesquisa e amizade. À Dra. Cátia Farias, pelo apoio dado e amizade. À CAPES, pela bolsa de estudo.

INTRODUÇÃOO planejamento ambiental, sobre o qual as ações de uso adequado dos recursos naturais precisam ser expressas sobre uma dimensão geográfica, apresenta a bacia hidrográfica como a grande unidade para a concepção do planejamento e a exePalavras-chave: Sustentabilidade. Rio. Características limnológicas. Qualidade ambiental. ResumoO presente estudo objetivou caracterizar físico-quimicamente a água da região do médio curso do Rio Pindaré sob jurisdição dos municípios de Pindaré-Mirim, Tufilândia, e Alto Alegre/MA. A fim de obter uma amostra representativa, foi coletada água em dez pontos distintos distribuídos no Rio Pindaré, ao longo de 24 meses em diferentes períodos sazonais, nos anos de 2010 e 2011. Os parâmetros físico-químicos analisados foram: temperatura, pH, turbidez, condutividade elétrica, oxigênio dissolvido e os íons amônio (NH4+), nitrito (NO2-), nitrato (NO3-) e fósforo total (PO43-). Durante o período de estudo, foi observada ampla variação na maioria das variáveis analisadas, com destaque para o fósforo total (PO43-) e a condutividade elétrica que apresentou resultados superiores aos estabelecidos pela resolução CONAMA 357/05. Quanto ao pH, as águas do Rio Pindaré foram na maior parte do tempo ácidas. As concentrações médias de nitrato variaram de 0,249 mgL-1 (período seco) e 0,267 mgL-1 (período chuvoso). Dos pontos coletados nos diferentes períodos, apenas no município de Alto Alegre se observou diferença estatística significativa quando o parâmetro testado foi o pH. Quando os parâmetros testados foram a condutividade elétrica e os ions amônio, nitrito e nitrato, observou-se diferença estatística significativa em todos os pontos testados nos três municípios com p≤0,05. Os resultados mostraram que o Rio Pindaré possui uma boa qualidade ambiental, apesar de apresentar desmatamento em suas margens comprometendo assim a sustentabilidade da bacia. As características físicas e químicas foram de extrema importância na dinâmica do ecossistema aquático sendo que os valores encontrados são considerados adequados para manutenção da vida aquática, segundo a resolução do CONAMA 357/2005. AbstractThis study aimed to characterize chemical-physical water area of the middle reaches of the river Pindaré under the jurisdiction of the municipalities of Pindaré-Mirim, Tufilândia and Alto Alegre / MA. In order to obtain a representative sample, water was collected in ten different points distributed in Rio Pindaré over 24 months in different seasonal periods in 2010 and 2011. The physical-chemical parameters analyzed were: temperature, pH, turbidity , electrical conductivity, dissolved oxygen and ammonium ion (NH4 +), nitrite (NO2), nitrate (NO3) and total phosphorus (PO43-). During the study period, there was wide variation in most of the variables analyzed, with emphasis on the total phosphorus (PO43-) and electrical conductivity presented results higher than those established by Resolution CONAMA 357/05. As to pH, the water of the river Pindaré were mostly acidic time. The average nitrate concentrations ran...

Water quality is mainly assessed using traditional water quality assessment methods that measure chemical parameters against established standards. The water quality index is used worldwide for water quality assessment. The main parameters evaluated include the total dissolved solids, electrical conductivity, nitrite, and nitrate. In this study, the WQI combined with microbiological analyses was used to assess the water quality of two rivers, Munim and Iguará. Data obtained in this study were then correlated using multivariate statistical analysis. Principal component analysis grouped the monitored sampling points into three clusters and identified temperature, Escherichia coli, and turbidity, as features correlated to the rainy season, while phosphorus, total dissolved solids, and biochemical oxygen demand are associated with the dry season. Four principal components explained 81.20% of the data variance during the studied seasons. The evaluated correlations indicated that in the rainy season, E. coli (~443.63 CFU/100 mL) and turbidity (~36.51 NTU) levels were the highest. However, in the dry season, the levels of phosphorus (~4.25 mg·L−1), total dissolved solids (145.46 mg·L−1), and dissolved oxygen (~9.89 mg·L−1) were the highest.

Endotoxemia is a condition caused by increasing levels of lipopolysaccharide (LPS) characterized by an impaired systemic response that causes multiple organ dysfunction. Lacticaseibacillus rhamnosus ATCC 9595 is a strain with probiotic potential which shows immunomodulatory properties. The incorporation of this bacterium in food rich in bioactive compounds, such as cupuaçu juice (Theobroma grandiflorum), could result in a product with interesting health properties. This work evaluated the effects of the oral administration of cupuaçu juice fermented with L. rhamnosus on the outcome of LPS-induced endotoxemia in mice. C57BL/6 mice (12/group) received oral doses (100 µL) of saline solution and unfermented or fermented cupuaçu juice (108 CFU/mL). After 5 days, the endotoxemia was induced by an intraperitoneal injection of LPS (10 mg/kg). The endotoxemia severity was evaluated daily using a score based on grooming behavior, mobility, presence of piloerection, and weeping eyes. After 6 h and 120 h, the mice (6/group) were euthanized for analysis of cell counts (in peritoneal lavage and serum) and organ weight. L. rhamnosus grew in cupuaçu juice and produced organic acids without the need for supplementation. The bacteria counts were stable in the juice during storage at 4 °C for 28 days. The fermentation with L. rhamnosus ATCC 9595 changed the metabolites profile of cupuaçu juice due to the biotransformation and enhancement of some compounds. In general, the administration of L. rhamnosus-fermented juice allowed a significant improvement in several characteristics of endotoxemic status (weight loss, hypothermia, severity index, cell migration). In addition, treatment with fermented juice significantly reduced the weight of the spleen, liver, intestine, and kidneys compared to the saline-treated endotoxemic group. Taken together, our data show that short-term intake therapy of cupuaçu juice fermented with L. rhamnosus ATCC 9595 can reduce systemic inflammation in an experimental model of LPS-induced endotoxemia in mice.

Fruit juices have been emerging as excellent vehicles for development of probiotic products due to their nutritional properties and presence of bioactive compounds. This work evaluated the growth and viability of Limosilactobacillus fermentum ATCC 23271 and Lacticaseibacillus rhamnosus ATCC 9595 in bacuri juice (Platonia insignis Mart., Clusiaceae). Both strains were able to grow in bacuri juice, without any supplementation. Viability was kept after 28 days of storage; however, growth was significantly higher for L. rhamnosus ATCC 9595 (7.40 ± 0.04 Log CFU/mL). Following this, the effects of bacterial inoculum and pulp concentration on growth and lactic acid production by L. rhamnosus ATCC 9595 were investigated using a central composite rotational design. The inoculum concentration was the main factor for obtaining the most favorable relation between growth and organic acid production (G/pH ratio). Among the tested conditions, those used in assay 6 allowed the best G/pH ratio (2.13) and higher lactic acid production (4.14 g/L). In these conditions, L. rhamnosus ATCC 9595 grown in bacuri juice showed the same resistance towards acidification or addition of lysozyme than when cultivated in MRS. Finally, the anti-infective effects of fermented and non-fermented juices were analyzed using Tenebrio molitor larvae infected by enteroaggregative Escherichia coli 042. The pre-treatment with supernatants of both fermented and non-fermented juices significantly increased the survival of E. coli-infected larvae. However, only the L. rhamnosus-fermented juice had protective effects when inoculated 2 h after infection. Collectively, the results obtained in this research allowed the basis for the development of a non-dairy probiotic product from bacuri juice.

The Corda river is the main source of fresh water for recreation, leisure, supply and irrigation to the municipality of Barra do Corda - MA. The objective of the present study was to evaluate the physicochemical parameters of Corda river’s water using the methodology described by the American Public Health Association. The water samples were collected in the seasonal period spanning between February and September of the year of 2018. The parameters which were analyzed during the study were pH, conductivity, turbidity, total dissolved solids and salinity, besides concentrations of nitrite, nitrate, and total phosphorus. Three principal components were identified during the PC Analysis. Those components explain more than 74% of the total variance observed during the rainy and dry season. Axis 1and 2 included variables which were related to quality of water and could be affected by the change in seasons. The results indicated that pH (7.11), P (2,82 mg L-1), NO3- (3,23 mg L-1), turbidity (35.82 NTU) and conductivity (35.83 µS/cm) parameters were most affected by changing from rainy to dry season.

The occurrence of damage on bacterial DNA (mediated by antibiotics, for example) is intimately associated with the activation of the SOS system. This pathway is related to the development of mutations that might result in the acquisition and spread of resistance and virulence factors. The inhibition of the SOS response has been highlighted as an emerging resource, in order to reduce the emergence of drug resistance and tolerance. Herein, we evaluated the ability of betulinic acid (BA), a plant-derived triterpenoid, to reduce the activation of the SOS response and its associated phenotypic alterations, induced by ciprofloxacin in Staphylococcus aureus. BA did not show antimicrobial activity against S. aureus (MIC > 5000 µg/mL), however, it (at 100 and 200 µg/mL) was able to reduce the expression of recA induced by ciprofloxacin. This effect was accompanied by an enhancement of the ciprofloxacin antimicrobial action and reduction of S. aureus cell volume (as seen by flow cytometry and fluorescence microscopy). BA could also increase the hyperpolarization of the S. aureus membrane, related to the ciprofloxacin action. Furthermore, BA inhibited the progress of tolerance and the mutagenesis induced by this drug. Taken together, these findings indicate that the betulinic acid is a promising lead molecule in the development helper drugs. These compounds may be able to reduce the S. aureus mutagenicity associated with antibiotic therapies.