RESUMO
The objective of this study was to evaluate the antimicrobial effectiveness of cinnamaldehyde (CIN) and potassium sorbate (P.S.), alone and in combination, against Salmonella Typhimurium and Staphylococcus aureus in vitro and in apple jam. Antimicrobial activity in vitro was investigated by minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC), time-kill assay and determination of fractional inhibitory concentration index. CIN MIC and MBC was 312 µg/mL. P.S. MIC and MBC were 2500 and 5000 µg/mL, respectively, against S. Typhimurium; and 10,000 and 20,000 µg/mL, respectively, against S. aureus. The compounds combined exhibited a synergistic effect (FIC < 0.5), inhibiting S. Typhimurium growth after 12â h and S. aureus after 24â h. The effect of CIN and P.S., at sub-inhibitory concentrations, against bacterial strains in apple jam was evaluated during storage. Physicochemical and sensory analyses were also performed. No cultivable S. Typhimurium or S. aureus cells were recovered in apple jam supplemented with CIN + P.S. on the third day of storage. The addition of CIN and P.S. did not affect the physicochemical properties and sensory evaluation showed a score above 7.0. CIN and P.S. association at sub-inhibitory concentrations was effective in controlling foodborne pathogens and improved the shelf life of apple jam.
RESUMO
In this study, a submerged aerated filter (SAF) using bottle caps as a support medium was evaluated. The system was fed with effluent from an upflow anaerobic sludge blanket system at ETE 2-South wastewater treatment plant, under different volumetric organic load rates (VOLRs). The population of a particular nitrifying microbial community was assessed by fluorescent in situ hybridization with specific oligonucleotide probes. The system showed an average removal of chemical oxygen demand (COD) equal to 76% for VOLRs between 2.6 and 13.6 kg COD m(-3)_media.day(-1). The process of nitrification in conjunction with the removal of organic matter was observed from applying VOLRs lower than 5.5 kg COD m(-3)_media.day(-1) resulting in 78% conversion of NH4(+)-N. As the applied organic load was reduced, an increase in the nitrifying bacteria population was observed compared with total 4'-6-diamidino-2-phenylindole (DAPI) stained cells. Generally, SAF using bottle caps as a biological aerated filter medium treating wastewater from an anaerobic system showed promising removal of chemical oxygen demand (COD) and conversion of NH4(+)-N.
Assuntos
Filtração/instrumentação , Purificação da Água/instrumentação , Embalagem de Alimentos , Nitrificação , Compostos Orgânicos/isolamento & purificação , Projetos PilotoRESUMO
This experiment measured total bacterial numbers in the gastrointestinal regions of semi-intensively cultured tilapia, Oreochromis niloticus L. (Cichlidae). Mean bacterial numbers were higher in both anterior and posterior gut than in stomach. The percentage of isolated species and the percentage of isolates from any particular species varied significantly among gastrointestinal tract regions. Aeromonas hydrophila, Aeromonas veronii, Burkholderia cepacia, Chromobacterium violaceum, Citrobacter freundii, Escherichia coli, Flavimonas oryzihabitans and Plesiomonas shigelloides were the most frequently isolated Gram-negative bacilli. From these samples, only Plesiomonas shigelloides was present in both gastrointestinal regions, with higher number in the posterior gut (76%), when compared to anterior gut (4.8%) and stomach (0.6%). Aeromonas hydrophila (0.6%), Escherichia coli (7.4%), and Flavimonas oryzihabitans were isolated only in the stomach, and Citrobacter freundii and Burkholderia cepacia were found only in the posterior gut. Chromobacterium violaceum was the dominant bacteria isolated from stomach and anterior gut, with 90% and 55%, respectively. Unidentified organisms comprised 0 - 39.3% of the gastrointestinal microflora
A flora bacteriana de diferentes partes do trato gastrintestinal de tilápia Oreochomis niloticus L. (Cichlidae) foi determinada. O número médio de bactérias foi maior no intestino anterior e posterior quando comparado ao estômago. A porcentagem total de espécies bacterianas isoladas e a porcentagem de espécies isoladas em uma espécie particular variaram significativamente entre as regiões do trato gastrintestinal. Aeromonas hydrophila, Aeromonas veronii, Burkholderia cepacia, Chromobacterium violaceum, Citrobacter freundii, Escherichia coli, Flavimonas oryzihabitans e Plesiomonas shigelloides foram os bacilos Gram-negativos encontrados com maior freqüência. Destas espécies, somente Plesiomonas shigelloides esteve presente em cada região do trato gastrintestinal, apresentando maior número no intestino posterior (76%), quando comparado com o intestino anterior (4.8%) e o estômago (0.6%). Aeromonas hydrophila (0.6%), Escherichia coli (7.4%), e Flavimonas oryzihabitans foram isoladas somente do estômago, e Citrobacter freundii e Burkholderia cepacia foram encontradas somente no intestino posterior. Chromobacterium violaceum foi a espécie dominante isolada do estômago e do intestino anterior com 90% e 55%, respectivamente. Organismos não identificados compreendem 0 39.3% da microbiota gastrintestinal
RESUMO
The aim of the present study was to investigate the reference ranges for haematological and biochemical values for Nile tilapia, Oreochromis niloticus (Cichlidae), cultivated in a semi-intensive system. Erythrocytes number was 6.93 ± 8.28 x 106/mm3, hemoglobin 10.52 ± 3.09g/dL of blood and hematocrit 31.85 ± 8.45%, mean corpuscular volume (MVC) 148.80 ±. 153.19µ3, mean corpuscular hemoglobin (MCH) 40.74 ± 34.19 pg and mean corpuscular hemoglobin concentration (MCHC) 35.24 ± 14.92%. Total plasma protein and glucose values obtained were 3.06 ± 0.65g/dl and 60.32 ± 20.22mg/dl, respectively. A correlation matrix was established to compare de degree of association among biometric data and hematological parameters, and among each of them and biochemical values. A positive correlation was observed among weight, length, MCV and MHC, as well as between length and hematocrit. The blood glucose level was positively correlated with weight and length, whereas total protein was positively correlated with hemoglobin. The erythrocytes count was positively correlated with hemoglobin and negatively correlated with MCV and MHC. Microscopy examination of blood smears revealed the presence of erythrocytes, neutrophils, lymphocytes, and monocytes. Under the conditions employed here, no basophils or eosinophils, nor their precursors, could be found in blood smears of Nile tilapia
O objetivo do presente estudo foi investigar os valores de referências hematológicos e bioquímicos para a tilápia do Nilo, Oreochromis niloticus (Cichlidae), cultivada em sistema semi-intensivo. A contagem de eritrócitos foi 6,93 ± 8,28 x 106/mm3, hemoglobina 10,52 ± 3,09g/dL de sangue, hematócrito 31,85 ± 8,45%, volume corpuscular médio (MVC) 148,80 ±.153,19µ3, hemoglobina corpuscular média (MCH) 40,74 ± 34,19pg e concentração de hemoglobina corpuscular média 35,24 ± 14,92%. Os valores de proteína plasmática total e da glicose obtidos foram de 3,06 ± 0,65g/dl e 60,32 ± 20,22mg/dl, respectivamente. Uma matriz de correlação foi estabelecida para comparar o grau de associação entre os dados biométricos e parâmetros hematológicos, e entre estes e os valores bioquímicos. Uma correlação positiva foi observada entre peso, comprimento, MCV e MHC, bem como entre comprimento e hematócrito. O nível de glicose sanguínea foi positivamente correlacionado com o peso e o comprimento, enquanto proteína total foi positivamente correlacionada com a hemoglobina. A contagem de eritrócito foi positivamente correlacionada com a hemoglobina e negativamente correlacionada com MCH e MHC. A observação microscópica do esfregaço sangüíneo revelou a presença de eritrócitos, neutrófilos, linfócitos e monócitos. Sob as condições empregadas no estudo não foram encontrados basófilos, ensinófilos ou seus precur
