Publications by authors named "Marianne Kreusch"

Polar environments pose extreme challenges for life due to low temperatures, limited water, high radiation, and frozen landscapes. Despite these harsh conditions, numerous macro and microorganisms have developed adaptive strategies to reduce the detrimental effects of extreme cold. A primary survival tactic involves avoiding or tolerating intra and extracellular freezing.

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The Antarctic continent is an extreme environment recognized mainly by its subzero temperatures. Fungi are ubiquitous microorganisms that stand out even among Antarctic organisms, primarily due to secondary metabolites production with several biological activities. Pigments are examples of such metabolites, which mainly occur in response to hostile conditions.

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Antarctic active volcanoes can disperse pyroclastic minerals at long distances, transporting nutrients and microorganisms to the surrounding glacial environment. The sedimented volcanic materials - called tephras - may interact with glacier ice and produce a unique environment for microbial life. This study aimed to describe the microbial community structure of an Antarctic glacier ice with tephra layers in terms of its taxonomic and functional diversity.

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Ultraviolet radiation, continuously reaching our planet's surface, is a type of electromagnetic energy within the wavelength range of 10 to 400 nm. Despite essential for all life on Earth, ultraviolet radiation may have severe adverse cellular effects, including DNA dimerization and production of reactive oxygen species. Radioresistant microorganisms can survive under high doses of ultraviolet radiation, enduring the direct and indirect effects on nucleic acids and other biomolecules.

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Spore settlement and development are bottlenecks for resilience of habitat-forming macroalgal species. These processes are directly related to temperature, a global stressor protagonist of ocean warming. The toxic effects of local pollutants such as copper may be worsened under a global warming scenario.

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Ocean warming is increasing and scientific predictions suggest a rise of up to 4°C in sea water temperatures. The combination of a polluted and warmer environment may be detrimental for aquatic species, especially for primary producers such as seaweeds. This study investigated the potential for interactive effects of an increased seawater temperature in a copper-rich environment on the photosynthetic pigments and metabolic compounds of the red seaweed Gelidium floridanum.

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Article Synopsis
  • Refined fuels, particularly gasoline, contribute significantly to marine pollution, affecting organisms like Ulva lactuca, a type of seaweed.
  • The study examined the impact of various gasoline concentrations on U. lactuca over different exposure times, revealing structural damage and biochemical changes such as altered metabolite levels.
  • Findings indicate that U. lactuca could be used as a biomonitoring species for coastal ecosystem health and has the potential to metabolize gasoline hydrocarbons, helping to clean up contaminated marine environments.
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The effect of ultraviolet (UV) radiation and copper (Cu) on apical segments of Pterocladiella capillacea was examined under two different conditions of radiation, PAR (control) and PAR+UVA+UVB (PAR+UVAB), and three copper concentrations, ranging from 0 (control) to 0.62, 1.25 and 2.

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The in vitro effect of cadmium (Cd) on apical segments of Pterocladiella capillacea was examined. Over a period of 7 days, the segments were cultivated with the combination of different salinities (25, 35, and 45 practical salinity units) and Cd concentrations, ranging from 0.17 to 0.

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This study investigated the effects of radiation (PAR+UVA+UVB) on the development and growth rates (GRs) of young gametophytes of Gelidium floridanum. In addition, photosynthetic pigments were quantified, carotenoids identified, and photosynthetic performance assessed. Over a period of 3 days, young gametophytes were cultivated under laboratory conditions and exposed to photosynthetically active radiation (PAR) at 80 μmol photons m(-2) s(-1) and PAR+UVA (0.

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Heavy metals, such as lead, copper, cadmium, zinc, and nickel, are among the most common pollutants found in both industrial and urban effluents. High concentrations of these metals cause severe toxic effects, especially to organisms living in the aquatic ecosystem. Cadmium (Cd), lead (Pb) and copper (Cu) are the heavy metals most frequently implicated as environmental contaminants, and they have been shown to affect development, growth, photosynthesis and respiration, and morphological cell organization in seaweeds.

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The photoacclimation responses of the brown macroalga Sargassum cymosum were studied to determine its cytochemical and ultrastructural organization, as well as photosynthetic pigments and performance. S. cymosum was cultivated in three salinities (30, 35 and 40 psu) under four irradiation treatments: PAR-only, PAR + UVA, PAR + UVB and PAR + UVA + UVB.

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Ultraviolet-B radiation (UVBR) affects plants in many important ways, including reduction of growth rate and primary productivity, and changes in ultrastructures. Rice (Oryza sativa) is one of the most cultivated cereals in the world, along with corn and wheat, representing over 50% of agricultural production. In this study, we examined O.

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The effect of lead and copper on apical segments of Gracilaria domingensis was examined. Over a period of 7 days, the segments were cultivated with concentrations of 5 and 10 ppm under laboratory conditions. The samples were processed for light, confocal, and electron microscopy, as well as histochemistry, to evaluate growth rates, mitochondrial activity, protein levels, chlorophyll a, phycobiliproteins, and carotenoids.

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