Produção e distribuição da biomassa da parte aérea do pinhão manso irrigado, aos dois anos de idade, em Santa Maria da Boa Vista-PE.

E em: CONGRESSO DA REDE BRASILEIRA DE TECNOLOGIA DE BIODIESEL, 3., 2009, Brasília, DF. Anais... Brasília, DF: MCT, 2009. p. 571-572

Use of fluorescent in situ hybridisation for the visualisation of Helicobacter pylori in real drinking water biofilms

A fluorescently labelled peptide nucleic acid (PNA) probe has been applied for the in situ detection of Helicobacter pylori in drinking water biofilms. The method was originally applied to real pipe samples removed from a drinking water distribution system (DWDS) but the curvature and the heavy fouling of the pipes prevented an accurate detection of the bacterium by epifluorescence microscopy. Therefore, two semi-circular flow cells were placed in a bypass of the DWDS, and coupons with up to 72 days of exposure were regularly sampled and analysed for the presence of H. pylori. In the flat surfaces of the coupons, it was possible to sparsely detect cells exhibiting similar morphology to H. pylori that were emitting the PNA probe fluorescent signal. Coupons were also visualised under the microscope before the hybridisation procedure to serve as negative controls and ensure the validity of the method. This work corroborates the findings already published elsewhere that this bacterium might be present in DWDS biofilms. The method requires, however, highly trained personnel for an accurate detection of the pathogen and will need simplification before being routinely used in standard water analysis laboratories.Fundação para a Ciência e a Tecnologia (FCT) European Commission Research Project SAFE

Use of fluorescent in situ hybridization for the visualization of Helicobacter pylori in real drinking water biofilms

A fluorescently labelled peptide nucleic acid (PNA) probe has been applied for the in situ detection of Helicobacter pylori in drinking water biofilms. The method was originally applied to real pipe samples removed from a drinking water distribution system (DWDS) but the curvature and the heavy fouling of the pipes prevented an accurate detection of the bacterium by epifluorescence microscopy. Therefore, two semi-circular flow cells were placed in a by-pass of the DWDS, and coupons with up to 72 days of exposure were regularly sampled and analysed for the presence of H. pylori. In the flat surfaces of the coupons, it was possible to sparsely detect cells exhibiting similar morphology to H. pylori that were emitting the PNA probe fluorescent signal. Coupons were also visualized under the microscope before the hybridization procedure to serve as negative controls and ensure the validity of the method. This work corroborates the findings already published elsewhere that this bacterium might be present in DWDS biofilms. The method requires however highly trained personnel for an accurate detection of the pathogen and will need simplification before being routinely used in standard water analysis laboratories.Fundação para a Ciência e Tecnologia (FCT) ; European Commission Research Project SAFER

Monitorização em contínuo da qualidade microbiológica da água e biofilmes associados utilizando um sistema de células de fluxo

A VIMÁGUA, Empresa de Água e Saneamento de Guimarães e Vizela E.I.M., criada em 19 de Fevereiro de 2002, tem por missão o abastecimento de água para consumo humano. Como tal, a manutenção da qualidade da água potável desde a estação de tratamento de água até aos consumidores é uma das nossas preocupações. Contudo, os sistemas de distribuição de água potável estão continuamente expostos a um fluxo de matéria orgânica biodegradável e de microrganismos. Estes últimos podem formar estruturas nas paredes das condutas – biofilmes – que lhes permite uma maior resistência à desinfecção. Com o propósito de monitorizar a formação de biofilmes e a sua interacção na qualidade da água instalou-se um sistema de amostragem in situ – reactor de células de fluxo - para a monitorização da formação de biofilmes em sistemas de água potável, e testar métodos de detecção de microrganismos patogénicos. Ao longo do tempo foi monitorizado o número de bactérias cultiváveis e totais, assim como parâmetros físico-químicos da água que abastecia o reactor. Em paralelo, foram desenvolvidas sondas de PNA para a detecção rápida de vários microrganismos (Escherichia coli; Helicobacter pylori) e testadas em laboratório, estando já a ser aplicadas no sistema de células de fluxo.Os autores gostariam de agradecer o apoio financeiro concedido pela FCT (Bolsa de doutoramento SFRH/BD/4705/2001) e pelo projecto europeu SAFER (Contrato n°EVK1-CT-200200108).info:eu-repo/semantics/publishedVersio

Detection of H. pylori in biofilms formed in a real drinking water distribution system using petide nucleic acid fluorescence in situ hybridization

Helicobacter pylori has previously been detected in real drinking water distribution systems (DWDS) using PCR based- techniques, but this approach will not discriminate between live and dead cells and their spatial relationship within the biofilm. On the other hand, in situ detection using fluorescence in situ hybridization (FISH) has been used successfully for spatial resolution but only in lab-grown experiments. In the present work, therefore, two flow cells were placed in a by-pass of the DWDS, and coupons were regularly removed for the detection of H. pylori by peptide nucleic acid (PNA) FISH, as well as for the assessment of CFU and total bacteria and visualization under scanning electron and epifluorescence microscopy. Chemical and physical parameters of the water feeding the flow cells were also monitored.Cells exhibiting similar morphology to H. pylori that were PNA FISH positive could be sparsely detected in the coupons. The technique showed promise despite the large morphologicalheterogeneity of microorganismspresent in biofilms and associated autofluorescence.Fundação para a Ciência e a Tecnologia (FCT)European Commission Research Project (SAFER