Browsing by Subject "Cyanobacteria"

Now showing 1 - 3 of 3
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    Cyanobacteria and Macroinvertebrate Relationships in Freshwater Benthic Communities beyond Cytotoxicity
    (MDPI, 2024-04-15) Ubero Pascal, Nicolás; Aboal, Marina; Zoología y Antropología Física
    Cyanobacteria are harmful algae that are monitored worldwide to prevent the effects of the toxins that they can produce. Most research efforts have focused on direct or indirect effects on human populations, with a view to gain easy accurate detection and quantification methods, mainly in planktic communities, but with increasing interest shown in benthos. However, cyanobacteria have played a fundamental role from the very beginning in both the development of our planet’s biodiversity and the construction of new habitats. These organisms have colonized almost every possible planktic or benthic environment on earth, including the most extreme ones, and display a vast number of adaptations. All this explains why they are the most important or the only phototrophs in some habitats. The negative effects of cyanotoxins on macroinvertebrates have been demonstrated, but usually under conditions that are far from natural, and on forms of exposure, toxin concentration, or composition. The cohabitation of cyanobacteria with most invertebrate groups is long-standing and has probably contributed to the development of detoxification means, which would explain the survival of some species inside cyanobacteria colonies. This review focuses on benthic cyanobacteria, their capacity to produce several types of toxins, and their relationships with benthic macroinvertebrates beyond toxicity.
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    Effects of living cyanobacteria, cyanobacterial extracts and pure microcystins on growth and ultrastructure of microalgae and bacteria
    (Elsevier, 2006-12-02) Valdor Alonso, Rut; Aboal, Marina; Bioquímica y Biología Molecular B e Inmunología
    In this study, we demonstrate the inhibitory effect of both cyanobacterial extracts and pure microcystins on the growth of microalgae and bacteria. This inhibitory effect was more persistent in pure microcystins than in the extracts, which lost their properties eight days after exposure. In addition, the effects on bacteria were longerlasting than those on microalgae. The microalgae exposed to both extracts and cultures of microcystin producing species showed morphological and ultrastructural alterations, even in cases where there was no clear effect on growth. The implications for colonisation and benthic communities structure and development are discussed in the context of biomonitoring.
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    Photoautotrophs and macroinvertebrate trophic relations in calcareous semiarid streams: the role of Cyanobacteria
    (Elsevier, 2022-06-01) Aboal, Marina; Belando, María Dolores; Ubero Pascal, Nicolás; González-Silvera, Daniel; López-Jiménez, José Ángel; Zoología y Antropología Física
    Photoautotrophs and macroinvertebrate trophic relations in Mediterranean streams, especially from semiarid areas, are still poorly known, as is the role of Cyanobacteria, which is the most frequently dominant photoautotroph. To investigate the role of Cyanobacteria as a food resource in these systems, the fatty acid composition of primary and secondary pro- ducers was investigated in two streams on a semiarid climatic gradient between 200 and 500 mm of rainfall in SE Spain. Fatty acid composition of photoautotrophs and macroinvertebrates differed among streams in summer and among sea- sons in each stream. Fatty acid fingerprints show that macroinvertebrates usually fed on the dominant photoautotroph assemblage and that Cyanobacteria represent the main food for all the feeding groups in the Alhárabe stream in winter although filamentous green algae were preferred in summer. Only scrapers consuming Chlorophyta displayed a selective feeding behaviour. The results show the importance of cyanobacteria as food for all collected macroinvertebrates in win- ter in some semiarid streams and confirm that fatty acids can be used as temporal and spatial markers in fluvial systems.