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Effect of low concentrations of synthetic surfactants on polycyclic aromatic hy...

The present study is focused on the effect of synthetic surfactants, at low concentration, on the kinetics of polycyclic aromatic hydrocarbons (PAH) biodegradation by Pseudomonas putida ATCC 17514 and addresses the specific issue of the effect of the surfactant on bacterial adhesion to PAH, which is believed to be an important mechanism for the uptake of hydrophobic compounds. For that purpose, three surfactant...

Interaction between non-disease causing microorganism and E. coli in catheter-a...

Most biofilms involved in catheter-associated urinary tract infections (CAUTIs) are polymicrobial, with disease causing (e.g. E. coli) and non-disease causing (NDC) microorganisms (Delftia tsuruhstensis, Achromobacter xylosoxidans, Burkholderia fungorum) frequently co-inhabiting the same catheter. Nevertheless, there is a lack of knowledge about the role that NDC microorganisms have on biofilm formation by E. c...

Effect of surfactants on the kinetics of anthracene biodegradation by pseudomon...

Impact of biofilms in simulated drinking water and urban heat supply systems

Biofouling and biocorrosion were studied in drinking water and heating water systems by forming biofilms on steel and on polymethylmetacrylate. In the drinking water system, biofilm development was more significant on corroded surfaces, suggesting that in these conditions they were largely protected from disinfection, probably because of sheltering and chlorine demand by corrosion products. In the urban heat su...

Competition between nitrospira spp. and nitrobacter spp. in nitrite-oxidizing b...

In this work the question was addressed if in nitrite-oxidizing activated sludge systems the environmental competition between Nitrobacter spp. and Nitrospira spp., which only recently has been discovered to play a role in these systems, is affected by the nitrite concentrations. Two parallel hemostats were inoculated with nitrifying-activated sludge containing Nitrospira and operated under identical condition...

Interaction of desulfovibrio desulfuricans biofilms with stainless steel surfac...

Aims: To study the influence of some metallic elements of stainless steel 304 (SS 304) on the development and activity of a sulfate-reducing bacterial biofilm, using as comparison a reference nonmetallic material polymethylmethacrylate (PMMA). Methods and Results: Desulfovibrio desulfuricans biofilms were developed on SS 304 and on a reference nonmetallic material, PMMA, in a flow cell system. Steady-state biof...

Evaluating heterotrophic growth in a nitrifying biofilm reactor using fluoresce...

The objective of this study was to evaluate the significance of heterotrophic growth in nitrifying biofilm reactors fed only with ammonium as an energy source. The diversity, abundance and spatial distribution of nitrifying bacteria were studied using a combination of molecular tools and mathematical modeling, in two biofilm reactors operated with different hydraulic retention times. The composition and distrib...

The influence of nickel on the adhesion ability of Desulfovibrio desulfuricans

The build-up of biofilms on metals surfaces may lead to severe corrosion, especially in the presence of sulphate-reducing bacteria (SRB). To prevent the deterioration of material caused by biofilms it is necessary to understand the processes governing biofilm development including mechanisms of cell adhesion. Additionally, corrosion of metallic surfaces due to bacteria may lead to the dissolution of metallic el...

Fluorene and phenanthrene uptake by Pseudomonas putida ATCC 17514 : kinetics an...

Pseudomonas putida ATCC 17514 was used as a model strain to investigate the characteristics of bacterial growth in the presence of solid fluorene and phenanthrene. Despite the lower water-solubility of phenanthrene, P. putida degraded this polycyclic aromatic hydrocarbon (PAH) at a maximum observed rate of 1.4 ± 0.1 mg Lˉ¹ hˉ¹, higher than the apparent degradation rate of fluorene, 0.8 ± 0.07 mg Lˉ¹ hˉ¹. The ro...

Tratamento de efluentes líquidos na indústria alimentar : o caso dos sectores v...

Esta comunicação apresenta os resultados obtidos com a aplicação de sistemas de tratamento de efluentes líquidos nas áreas vinícola e cervejeira. O trabalho incidiu no arranque, operação e optimização de um reactor descontínuo sequencial (SBR, Sequencing Batch Reactor) recentemente implantado na Adega Cooperativa de Ponte da Barca, assim como no estudo do fenómeno da granulação num reactor anaeróbio de leito de...