BIFIDOBACTÉRIAS: ISOLAMENTO, IDENTIFICAÇÃO E APLICAÇÃO EM ALIMENTOS PROBIÓTICOS

This review aimed to describe the main culture media that have been developed for the isolation and enumeration of bifidobacteria and the molecular methods used for identification of this genus and its species. The criteria for probiotic bifidobacteria selection for their technological application were also demons trated (as tolerance to low pH, presence of oxygen and presence of ingredients and additives). Various studies carried out using a bifidobacteria in the development of probiotic foods were cited. It can be concluded that the constant consumer’s search for balance of health tends to increase the market for probiotic foods, stimulating research in the discovery of new strains with this activity and diversification of products.Esta revisão de literatura teve por objetivo descrever os principais meios de cultura já desenvolvidos para o isolamento e enumeração de bifidobactérias, e os métodos moleculares utilizados para a identificação desse gênero e de suas espécies. Os critérios de seleção das bifidobactérias probióticas visando à aplicação tecnológica também foram abordados (como tolerância a pH baixo, presença de oxigênio e presença de ingredientes e aditivos). Diversas pesquisas realizadas com bifidobactérias para o desenvolvimento de alimentos probióticos foram citadas. A importância do isolamento e identificação das bifidobactérias envolve a aplicação desses microrganismos como agentes probióticos em alimentos. Pode-se concluir que a constante busca pela saúde tende a aumentar o consumo de alimentos probióticos, estimulando a diversificação de produtos e a descoberta de novas cepas com essa função

Development and validation of real-time PCR screening methods for detection of cry1A.105 and cry2Ab2 genes in genetically modified organisms

Primers and probes were developed for the element-specific detection of cry1A.105 and cry2Ab2 genes, based on their DNA sequence as present in GM maize MON89034. Cry genes are present in many genetically modified (GM) plants and they are important targets for developing GMO element-specific detection methods. Element-specific methods can be of use to screen for the presence of GMOs in food and feed supply chains. Moreover, a combination of GMO elements may indicate the potential presence of unapproved GMOs (UGMs). Primer-probe combinations were evaluated in terms of specificity, efficiency and limit of detection. Except for specificity, the complete experiment was performed in 9 PCR runs, on 9 different days and by testing 8 DNA concentrations. The results showed a high specificity and efficiency for cry1A.105 and cry2Ab2 detection. The limit of detection was between 0.05 and 0.01 ng DNA per PCR reaction for both assays. These data confirm the applicability of these new primer-probe combinations for element detection that can contribute to the screening for GM and UGM crops in food and feed samples

Optimization of random amplified polymorphic DNA protocol for molecular identification of Lophius gastrophysus Otimização do protocolo de amplificação randômica de DNA polimórfico para identificação molecular de Lophius gastrophysus

Lophius gastrophysus has important commercial value in Brazil particularly for foreign trade. In this study, we described the optimization of Random Amplified Polymorphic DNA (RAPD) protocol for identification of L. gastrophysus. Different conditions (annealing temperatures, MgCl concentrations, DNA quantity) were tested to find reproducible and adequate profiles. Amplifications performed with primers A01, ² A02 and A03 generate the best RAPD profiles when the conditions were annealing temperature of 36ºC, 25 ng of DNA quantity and 2.5 mM MgCl2. Exact identification of the species and origin of marine products is necessary and RAPD could be used as an accurate, rapid tool to expose commercial fraud.Lophius gastrophysus apresenta importante valor comercial no Brasil, principalmente para a exportação. Neste estudo, descrevemos uma otimização do protocolo de amplificação aleatória de DNA polimórfico (RAPD) para identificação de L. gastrophysus. Diferentes condições (temperatura de recozimento, quantidade de DNA e concentração de MgCl2) foram testadas para obter perfis reprodutíveis. Os iniciadores A01, A02 e A03 geraram os melhores resultados de amplificação quando utilizados temperatura de recozimento de 36ºC, 25 ng de DNA e 2,5 mM de MgCl2. A identificação exata de espécies e da origem dos produtos marinhos faz-se necessária e a RAPD é uma ferramenta rápida e precisa para expor fraudes comerciais

Brain and liver lipid peroxidation levels following acute and short-term lindane administration in the rat

Oxidative stress-related parameters in rat brain and liver were evaluated following acute (60 mg/kg i.p., 2 and 24 h after dosing) or short-term (1000 ppm in the diet for 90 days) lindane administration. Both treatments elicited a significant accumulation of lindane in brain and liver, with convulsions observed in short-term and 24-h lindane-treated rats. In these conditions, lindane exposure did not alter brain lipid peroxidation, assessed as thiobarbituric acid reactants formation and spontaneous chemiluminescence, parameters that were enhanced in the liver. The activities of antioxidant enzymes in the brain (Superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase and glucose 6-phosphate dehydrogenase) were not modified by acute lindane treatment, while brain glutathione content was significantly reduced by 13%. It is concluded that lindane does not alter the oxidative stress status of the brain as occurs in liver, regardless of the time of exposure of rats to