8 documents found, page 1 of 1
How the performance of a biological pre-oxidation step can affect a downstream ...
Tânia F. C. V. Silva; Eloísa Vieira; Ana R. Lopes; Olga C. Nunes; Amélia Fonseca; Isabel Saraiva; Rui A. R. Boaventura; Vítor J. P. VilarThe main purpose of this work was to assess the (i) short-term effect of the main nitrification and denitrification variables on the nitrogen's biological removal via nitrite from highstrength leachates, and (ii) the effect of the presence/absence of nitrites/nitrates in a downstream photo-oxidation process. The biological reaction rates were evaluated as a function of several parameters: (i) temperature, disso...
Comparison of the bacterial composition of two commercial composts with differe...
Maria Elisabete F. Silva; Ana R. Lopes; Ana Cristina Cunha Queda; Olga C. NunesPreviously, two municipal solid waste commercial composts (MSW1 and MSW2) were characterized. Although sharing the same type of raw material, most of their physicochemical, stability and maturity properties differed. The present study aimed to characterize them at a microbiological level, and to infer on possible relationships between the composts properties and the structure of their bacterial communities. Bot...
Production of microparticles of molinate degrading biocatalysts using the spray...
Ana R. Lopes; Vera M. Sousa; Berta N. Estevinho; José P. Leite; Nuuno F. F. Moreira; Luís Gales; Fernando Rocha; Olga C. NunesPrevious studies demonstrated the capability of mixed culture DC1 to mineralize the thiocarbamate herbicide molinate through the activity of molinate hydrolase (MolA). Because liquid suspensions are not compatible with long-term storage and are not easy to handle when bioremediation strategies are envisaged, in this study spray drying was evaluated as a cost-effective method to store and transport these molinat...
Responses of the alga Pseudokirchneriella subcapitata to long-term exposure to ...
Manuela D. Machado; Ana R. Lopes; Eduardo V. SoaresThe green alga Pseudokirchneriella subcapitata has been widely used in ecological risk assessment, usually based on the impact of the toxicants in the alga growth. However, the physiological causes that lead algal growth inhibition are not completely understood. This work aimed to evaluate the biochemical and structural modifications in P. subcapitata after exposure, for 72 h, to three nominal concentrations of...
Relationships among bulk soil physicochemical, biochemical, and microbiological...
Ana R. Lopes; Diana Bello; Ángeles Prieto-Fernández; Carmen Trasar-Cepeda; Célia M. Manaia; Olga C. NunesThe microbial communities of bulk soil of rice paddy fields under an ancient organic agriculture regimen, consisting on an alfalfa-rice rotation system, were characterized. The drained soil of two adjacent paddies at different stages of the rotation was compared before rice seeding and after harvesting. The relationships among the soil microbial, physicochemical, and biochemical parameters were investigated usi...
Bacterial community variations in an alfalfa- rice rotation system revealed by ...
Ana R. Lopes; Célia M. Manaia; Olga C. NunesCrop rotation is a practice harmonized with the sustainable rice production. Nevertheless, the implications of this empirical practice are not well characterized, mainly in relation to the bacterial community composition and structure. In this study, the bacterial communities of two adjacent paddy fields in the 3rd and 4th year of the crop rotation cycle and of a nonseeded subplot were characterized before rice...
Microbial degradation of the herbicide molinate by defined cultures and in the ...
Olga C. Nunes; Ana R. Lopes; Célia M. ManaiaMolinate is a thiocarbamate herbicide used worldwide in rice crop protection. As with other pesticides, molinate is a recognized environmental pollutant, detected in soils, irrigation water, or rivers and bio-accumulated by some wildlife forms. For this reason, and in spite of its low toxicity to humans, environmental protection measures, which include reduction of use and/or remediation processes, are recommen...
Bacillus purgationiresistans sp nov., isolated from a drinking-water treatment ...
Ivone Vaz Moreira; Vânia Figueira; Ana R. Lopes; Alexandre Lobo da Cunha; Cathrin Spröer; Peter Schumann; Olga C. Nunes; Célia M. ManaiaA Gram-positive, aerobic, non-motile, endospore-forming rod, designated DS22(T), was isolated from a drinking-water treatment plant. Cells were catalase- and oxidase-positive. Growth occurred at 15-37 degrees C, at pH 7-10 and with <8% (w/v) NaCl (optimum growth: 30 degrees C, pH 7-8 and 1-3% NaCl). The major respiratory quinone was menaquinone 7, the G + C content of the genomic DNA was 36.5 mol% and the cell ...