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- A importância do mundo invisível dos micróbios na Ria FormosaPublication . Mendes, Pedro; Galvão, Helena; Caetano, Sandra; Icely, John; Newton, AliceCom o desenvolvimento da microscopia de epifluorescência e técnicas sensíveis de radioisótopos na década de 1970, a abundância e atividade de microrganismos pôde ser observada e estudada em águas marinhas. Estas observações resultaram num novo conceito de rápida transferência e reciclagem de matéria orgânica através de um ciclo microbiano, o “microbial loop”.
- Role of microbes in the Ria Formosa lagoonPublication . Galvão, Helena M.; Mendes, Pedro; Caetano, Sandra; Icely, John; Newton, AliceWith the development of epifluorescence microscopy and sensitive radioisotope techniques, high abundance and activity of microorganisms was observed in marine waters since 1970s and 1980s. These observations resulted in a new concept of rapid turn-over and recycling of organic matter through a ‘microbial loop’ (Azam et al., 1983; Azam, 1998). Figure 5.1 illustrates fluxes of material through the marine microbial loop. Main processes are C fixation by photosynthetic microorganisms (prokaryotic and eukaryotic) with exudation losses of Dissolved Organic Matter (DOM), which is incorporated by heterotrophic bacteria. Phagotrophic protists in turn graze both autotrophs and bacteria producing ‘sloppy feeding’ loss of DOM, which returns to the loop. DOM is remineralized by all microorganisms into Dissolved Inorganic Nutrients (DIN), which are taken up by autotrophic and heterotrophic microorganisms.
- Cyanobacteria blooms and cyanotoxin occurrence in the Guadiana (SE - Portugal): preliminary resultsPublication . Caetano, Sandra; Miguel, Rute; Mendes, Pedro; Galvão, Helena M.; Barbosa, Ana B.Cyanobacteria are a recognised public health hazard, because the majority of species is able to produce toxins. The monitoring is usually restricted to freshwater environments, like lakes or dams used for water supply. Cyanobacteria blooms have been regularly reported in the Guadiana River and high estuary and most of the observed cyanobacteria were toxin producers.