Microcystin profiles in European noble crayfish Astacus astacus and water in Lake Steinsfjorden, Norway.

Lake Steinsfjorden, an important noble crayfish (Astacus astacus) habitat, is often affected by blooms of Planktothrix spp. that produce microcystins (MCs). A poor correlation between MCs by ELISA in the water and in crayfish tissue in a study in 2015 prompted further investigation by LC-HRMS.

Microcystins in European Noble Crayfish in Lake Steinsfjorden, a -Dominated Lake.

Lake Steinsfjorden, an important Norwegian location for noble crayfish (), is often affected by cyanobacterial blooms caused by microcystin (MC)-producing spp. The impact of MCs on noble crayfish as a food source and crayfish health is largely unknown. We investigated the quantities and correlations of MCs in noble crayfish and lake water during and after a cyanobacterial bloom peaking in June-July 2015.

A European Multi Lake Survey dataset of environmental variables, phytoplankton pigments and cyanotoxins.

Under ongoing climate change and increasing anthropogenic activity, which continuously challenge ecosystem resilience, an in-depth understanding of ecological processes is urgently needed. Lakes, as providers of numerous ecosystem services, face multiple stressors that threaten their functioning. Harmful cyanobacterial blooms are a persistent problem resulting from nutrient pollution and climate-change induced stressors, like poor transparency, increased water temperature and enhanced stratification.

Temperature Effects Explain Continental Scale Distribution of Cyanobacterial Toxins.

Insight into how environmental change determines the production and distribution of cyanobacterial toxins is necessary for risk assessment. Management guidelines currently focus on hepatotoxins (microcystins). Increasing attention is given to other classes, such as neurotoxins (e.

Simulating water quality and ecological status of Lake Vansjø, Norway, under land-use and climate change by linking process-oriented models with a Bayesian network.

Excess nutrient inputs and climate change are two of multiple stressors affecting many lakes worldwide. Lake Vansjø in southern Norway is one such eutrophic lake impacted by blooms of toxic blue-green algae (cyanobacteria), and classified as moderate ecological status under the EU Water Framework Directive. Future climate change may exacerbate the situation.

Environmental Conditions Determine the Course and Outcome of Phytoplankton Chytridiomycosis.

Chytrid fungi are highly potent parasites of phytoplankton. They are thought to force phytoplankton organisms into an evolutionary arms race with high population diversity as the outcome. The underlying selection regime is known as Red Queen dynamics.

Spectrophotometric Analysis of Pigments: A Critical Assessment of a High-Throughput Method for Analysis of Algal Pigment Mixtures by Spectral Deconvolution.

The Gauss-peak spectra (GPS) method represents individual pigment spectra as weighted sums of Gaussian functions, and uses these to model absorbance spectra of phytoplankton pigment mixtures. We here present several improvements for this type of methodology, including adaptation to plate reader technology and efficient model fitting by open source software. We use a one-step modeling of both pigment absorption and background attenuation with non-negative least squares, following a one-time instrument-specific calibration.

The Red Queen race between parasitic chytrids and their host, Planktothrix: a test using a time series reconstructed from sediment DNA.

Parasitic chytrid fungi (phylum Chytridiomycota) are known to infect specific phytoplankton, including the filamentous cyanobacterium Planktothrix. Subspecies, or chemotypes of Planktothrix can be identified by the presence of characteristic oligopeptides. Some of these oligopeptides can be associated with important health concerns due to their potential for toxin production.

LC-MS analysis with thiol derivatization to differentiate [Dhb(7)]- from [Mdha(7)]-microcystins: analysis of cyanobacterial blooms, Planktothrix cultures and European crayfish from Lake Steinsfjorden, Norway.

Kinetic studies showed that [Asp(3), Dhb(7)]MC-RR reacted with mercaptoethanol hundreds of times more slowly than MC-RR and a range of other [Mdha(7)]-containing microcystin congeners. The difference in reaction rate was sufficiently large that derivatization of microcystin-containing samples with mercaptoethanol, followed by LC-MS analysis, clearly discriminated between microcystins containing the isobaric [Dhb(7)]- and [Mdha(7)]-groups. Application of this approach, using LC-MS with both-ion trap and triple-quadrupole mass spectrometers, to water samples and Planktothrix cultures from Lake Steinsfjorden, Norway, demonstrated the presence of [Asp(3), Dhb(7)]MC-RR (5), [Asp(3)]MC-RY (14), and [Asp(3)]MC-LY (16), as well as analogues tentatively identified as [Asp(3)]MC-RR (4), [Asp(3), DMAdda(5), Dhb(7)]MC-LR (6), [Asp(3), Dhb(7)]MC-HtyR (8), [Asp(3)]MC-HtyR (9), [Asp(3), Dhb(7)]MC-LR (10), [Asp(3)]MC-LR (11), [Asp(3), Dhb(7)]MC-RY (15), and [Asp(3), Dhb(7)]MC-LY (17), together with low levels of several other analogues.

The impact of cyanobacteria on growth and death of opportunistic pathogenic bacteria.

Climate change may cause increased microbial growth in water sources and more knowledge is required on how this may affect the hygienic water quality, i.e., whether increased occurrence of cyanobacteria and algae may stimulate the growth rate of opportunistic pathogenic bacteria.

Morphological and phylogenetic analysis of Anabaenopsis abijatae and Anabaenopsis elenkinii (nostocales, cyanobacteria) from tropical inland water bodies.

Anabaenopsis spp. are heterocytous cyanobacteria commonly found in tropical, subtropical, and temperate water bodies. So far, the knowledge about the phylogeny of this genus is poor.

Diversity of Microcystis aeruginosa isolates (Chroococcales, Cyanobacteria) from East-African water bodies.

With exception of South Africa, very little is known about the presence and abundance of toxic cyanobacteria and cyanobacterial blooms on the African continent. The close proximity between society and nature, and the use of the sparse water resources as drinking water in large parts of Africa, lead to the recognition that more knowledge on toxic cyanobacterial blooms is of major importance. The bloom forming cyanobacterium Microcystis aeruginosa is known to produce cyclic heptatoxins (microcystins) which can be toxic to humans.