Encontrados 46 documentos, a visualizar página 1 de 5
The action of selected isothiocyanates on bacterial biofilm prevention and control
Borges, A.; Simões, Lúcia C.; Saavedra, Maria J.; Simões, M.The activity of two selected isothiocyanates (ITCs), allylisothiocyanate (AITC) and 2-phenylethy-lisothiocyanate (PEITC) was evaluated on the prevention and control of biofilms formed by Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus and Listeria monocytogenes. In addition, the effect of ITCs was also tested on planktonic cell susceptibility, bacterial motility and adhesion. Biofilm prevention ...
Biofilms in drinking water : problems and solutions
Simões, Lúcia C.; Simões, M.The main goal of water companies is to deliver to each consumer microbiologically safe drinking water (DW), adequate in quantity and delivery pressure and acceptable in terms of taste, odour and appearance. Drinking water distribution systems (DWDS) are known to harbour biofilms, even in the continuous presence of a disinfectant. These biofilms are a source of planktonic bacteria, which will remain present when...
Biofilms in drinking water
Simões, Lúcia C.The provision of safe drinking water (DW) is a top priority issue in any civilized society. Safe DW is a basic need to human development, health and well-being. The main challenge to the DW industry is to deliver a product that is microbiologically and chemically safe, aesthetically pleasing and adequate in quantity and delivery pressure. Normally, the water that leaves a treatment station has quality, but its ...
Proposal for a method to estimate nutrient shock effects in bacteria
Azevedo, N. F.; Bragança, S. M.; Simões, Lúcia C.; Cerqueira, L.; Almeida, Carina; Keevil, C. W.; Vieira, M. J.Plating methods are still the golden standard in microbiology; however, some studies have shown that these techniques can underestimate the microbial concentrations and diversity. A nutrient shock is one of the mechanisms proposed to explain this phenomenon. In this study, a tentative method to assess nutrient shock effects was tested. Findings To estimate the extent of nutrient shock effects, two strains is...
A comparative study of drinking water biofilm monitoring with flow cell and Pro...
Simões, Lúcia C.; Simões, M.; Vieira, Maria JoãoMonitoring of drinking water (DW) biofilm formation under different process conditions was performed using two distinct bioreactors: a Propella™ and a flow cell system. Biofilms were grown on polyvinyl chloride (PVC) and stainless steel (SS) coupons under laminar (Reynolds number: 2000) and turbulent (Reynolds number: 11000) flow. The parameters analysed were the numbers of total and cultivable bacteria. The im...
Comparison of methods to assess biofilm disinfection and recovery by drinking w...
Simões, Lúcia C.; Simões, M.; Vieira, M. J.Drinking water (DW) distribution systems are known to harbour biofilms even in the presence of disinfectants. DW biofilms are constituted by microbial communities adapted to low nutrient concentrations and high chlorine levels. Biofilm formation and resistance to disinfection have been recognized as important factors that contribute to the survival and persistence of microbial contamination in DW. The purpose o...
Persister cells in a biofilm treated with a biocide
Simões, Lúcia C.; Lemos, Madalena; Pereira, Ana M.; Abreu, Ana C.; Saavedra, Maria J.; Simões, M.This study investigated the physiology and behaviour following treatment with ortho-phthalaldehyde (OPA), of Pseudomonas fluorescens in both the planktonic and sessile states. Steady-state biofilms and planktonic cells were collected from a bioreactor and their extracellular polymeric substances (EPS) were extracted using a method that did not destroy the cells. Cell structure and physiology after EPS extractio...
The effects of metabolite molecules produced by drinking water-isolated bacteri...
Simões, Lúcia C.; Simões, M.; Vieira, M. J.The elucidation of the mechanisms by which diverse species survive and interact in drinking water (DW) biofilm communities may allow the identification of new biofilm control strategies. The purpose of the present study was to investigate the effects of metabolite molecules produced by bacteria isolated from DW on biofilm formation. Six opportunistic bacteria, viz. Acinetobacter calcoaceticus, Burkholderia cepa...
The effects of glutaraldehyde on the control of single and dual biofilms of Bac...
Simões, Lúcia C.; Lemos, Madalena; Araújo, Paula; Pereira, Ana M.; Simões, M.Glutaraldehyde (GLUT) was evaluated for control of single and dual species biofilms of Bacillus cereus and Pseudomonas fluorescens on stainless steel surfaces using a chemostat system. The biofilms were characterized in terms of mass, cell density, total and matrix proteins and polysaccharides. The control action of GLUT was assessed in terms of inactivation and removal of biofilm. Post-biocide action was chara...
Microbial interactions on biofilm formation by drinking water autochthonous mic...
Simões, Lúcia C.Tese de doutoramento em Chemical and Biological Engineering ; The provision of safe drinking water (DW) is a top priority issue in any civilized society. Safe DW is a basic need to human development, health and well-being. The main challenge to the DW industry is to deliver a product that is microbiologically and chemically safe, aesthetically pleasing and adequate in quantity and delivery pressure. Normally, ...
| Financiadores do RCAAP | |||||||
|
|
|
|
|
|
||