A5013960136- Aquatic Ecosystems and Phytoplankton Dynamics
- Microbial Community Ecology and Physiology
- Biocrusts and Microbial Ecology
- Marine and coastal ecosystems
- Environmental DNA in Biodiversity Studies
- Aquatic Ecosystems and Biodiversity
- Diatoms and Algae Research
- Algal biology and biofuel production
- Protist diversity and phylogeny
- Marine Toxins and Detection Methods
- bioluminescence and chemiluminescence research
- Photosynthetic Processes and Mechanisms
- Microbial Natural Products and Biosynthesis
- Freshwater macroinvertebrate diversity and ecology
- Coastal wetland ecosystem dynamics
- Peatlands and Wetlands Ecology
- Land Use and Ecosystem Services
- Genomics and Phylogenetic Studies
- Aquatic Invertebrate Ecology and Behavior
- Geology and Paleoclimatology Research
- Conservation, Biodiversity, and Resource Management
- Chemical Synthesis and Analysis
- Identification and Quantification in Food
- Molecular Biology Techniques and Applications
- Fish Ecology and Management Studies
Universität Innsbruck
2016-2025
Austrian Academy of Sciences
2004-2021
Fondazione Edmund Mach
2019-2021
Brides-les-Bains
2021
University of Lausanne
2021
University of Applied Sciences and Arts of Southern Switzerland
2019-2020
Austrian Agency for Health and Food Safety
2019-2020
Institut National de Recherche pour l'Agriculture, l'Alimentation et l'Environnement
2019-2020
University of Hawaiʻi at Mānoa
2008
University of Zurich
1999-2008
ABSTRACT The cyanobacterium Microcystis sp. frequently develops water blooms consisting of organisms with different genotypes that either produce or lack the hepatotoxin microcystin. In order to monitor development microcystin ( mcy ) during seasonal cycle total population, were quantified by means real-time PCR in Lake Wannsee (Berlin, Germany) from June 1999 October 2000. Standard curves established relating cell concentrations threshold (the number at which fluorescence passes a set...
ABSTRACT The working hypotheses tested on a natural population of Microcystis sp. in Lake Wannsee (Berlin, Germany) were that (i) the varying abundance microcystin-producing genotypes versus non-microcystin-producing is key factor for microcystin net production and (ii) occurrence gene related to colony morphology, particularly size. To test these hypotheses, samples fractionated by size with sieving procedure during summer 2000. Each class was analyzed cell numbers, proportion genotypes,...
Summary To investigate the abundance of active and inactive microcystin genotypes in populations filamentous cyanobacterium Planktothrix spp., individual filaments were grown as clonal strains laboratory analysed for synthetase ( mcy ) genes microcystin. Twenty‐three green‐pigmented P. agardhii originating mostly from shallow water bodies fell into two groups, those possessing mcyA lacking mcyA. In contrast, all 49 that assigned to red‐pigmented rubescens contained . One strain eight total...
Blooms that are formed by cyanobacteria consist of toxic and nontoxic strains.The mechanisms result in the occurrence strains enigmatic.All filamentous cyanobacterium Planktothrix were isolated from 9 European countries found to have lost 90% a large microcystin synthetase (mcy) gene cluster encoded synthesis peptide (MC).Those still contain flanking regions mcy along with remnants transposable elements between.The majority coding for distinct thioesterase type II (mcyT), which is putatively...
The Nyanza Gulf is a large shallow bay of Lake Victoria suffering from eutrophication by human activities. In order to characterize the harmful algal bloom formation as consequence eutrophication, both spatially and seasonally, environmental conditions, phytoplankton community composition, microcystin (MC) concentrations were investigated monthly Kisumu Bay, bimonthly center gulf, well quarterly Rusinga Channel main basin between July 2008 September 2009. sites located in Bay central gulf...
Since the cyanobacterium Planktothrix rubescens, which dominates phytoplankton community in Lake Zürich, is generally considered toxic to zooplankton, we addressed question whether co-occurring zooplankton species have developed adaptive responses.Artificially shortened filaments (<30 µm length) of P.rubescens significantly reduced survival Thamnocephalus platyurus (Crustacea, Branchiopoda, Anostraca) naturally occurring temporary ponds.In contrast Thamnocephalus, co-existing was unaffected...
Parasitic chytrid fungi can inflict significant mortality on cyanobacteria but frequently fail to keep cyanobacterial dominance and bloom formation in check. Our study tested whether oligopeptide production, a common feature many cyanobacteria, be defensive mechanism against parasitism. The employed the strain Planktothrix NIVA-CYA126/8 its mutants with knockout mutations for microcystins, anabaenopeptins, microviridins, major classes found NIVA-CYA126/8. Four strains were used as parasite...
Freshwater ecosystems are continuously affected by anthropogenic pressure. One of the main sources contamination comes from wastewater treatment plant (WWTP) effluents that contain wide range micro- and macropollutants. Chemical composition, toxicity levels impact treated (TEs) on recipient aquatic may strongly differ depending origin. Compared to urban TEs, hospital ones more active pharmaceutical substances. Benthic diatoms relevant ecological indicators because their high species...
ABSTRACT The filamentous cyanobacteria Planktothrix spp. occur in the temperate region of Northern hemisphere. red-pigmented rubescens bacteria deep, physically stratified, and less eutrophic lakes. is a known producer toxic heptapeptide microcystin (MC), which produced nonribosomally by large enzyme complex consisting peptide synthetases polyketide synthases encoded total nine genes ( mcy genes). differ their cellular MC contents as well production variants; however, mechanisms favoring...
Abstract Microcystins (MCs) are toxic heptapeptides that produced by filamentous cyanobacteria Planktothrix rubescens and agardhii via nonribosomal peptide synthesis. MCs share a common structure cyclo (‐D‐Alanine 1 ‐L‐X 2 ‐ D‐erythro‐ß‐iso‐aspartic acid 3 ‐L‐Z 4 ‐Adda 5 ‐D‐Glutamate 6 N ‐methyl‐dehydroalanine 7 ) where X Z variable L‐amino acids in positions 2, of the molecule. Part mcy B gene (1,451 bp) is involved activation amino during MC synthesis was sequenced 49 strains containing...
Abstract Microcystins (MCs) are cyclic heptapeptides, which the most abundant toxins produced by cyanobacteria in freshwater. The phytoplankton of many freshwater lakes Eastern Africa is dominated cyanobacteria. Less known, however, on occurrence MC producers and production MCs. Twelve Ugandan habitats ranging from mesotrophic to hypertrophic conditions were sampled May June 2004 April 2008 analyzed for their physicochemical parameters, composition, concentrations. Among group potential...
The increasing incidence of mass developments Cyanobacteria in fresh- and brackish water is a matter growing concern due to the production toxins that threaten human livestock health. are produced by freshwater comprise hepatotoxins (cyclic peptides such as microcystins nodularin, well alkaloids cylindrospermopsin) neurotoxins (alkaloids anatoxin-a, anatoxin-a(S) saxitoxins). variation toxicity between within species has been recognised for long time. However, toxic non-toxic genotypes...
Abstract Sicilian reservoirs constitute the most important water resources available on island. During summer 2001, intense utilization of Lake Arancio reservoir reduced level significantly, which coincided with formation blooms formed by microcystin (MC)‐producing cyanobacterium Microcystis aeruginosa . 2003, was continuously filled and vertical stratification column maintained resulting in five to sixfold lower cell numbers M. For both years, a significant relationship between MC net...
Anabaenopeptins (AP) are bioactive cyclic hexapeptides synthesized nonribosomally in cyanobacteria. APs characterized by several conserved motifs, including the ureido bond, N-methylation position 5, and d-Lys 2. All other positions of AP molecule variable, resulting numerous structural variants. We have identified a nonribosomal peptide synthetase (NRPS) operon from Planktothrix agardhii strain CYA126/8 consisting five genes (apnA to apnE) encoding six NRPS modules confirmed its role...
The understanding of how environmental factors regulate toxic secondary metabolite production in cyanobacteria is important to guarantee water quality. Very little known on the regulation benthic cyanobacteria. In this study, physiological heptapeptide microcystin (MC) and nontoxic related peptide nostophycin (NP) cyanobacterium Nostoc sp. strain 152 was studied under contrasting conditions. A 2 k levels factorial design used, where number four that have been tested: reduction temperature...
This review aims to summarise the outcomes of some recent European research concerning toxic cyanobacteria and cyanotoxins, with an emphasis on developments within framework CYANOCOST Action (COST ES1105, Cyanobacterial Blooms Toxins in Water Resources: Occurrence, Impacts Management). State art management capabilities Europe have benefitted from input pure applied life sciences, human animal health sectors, water engineers, economists planners. Many these professional groups been brought...
Abstract Toxic freshwater cyanobacteria form harmful algal blooms that can cause acute toxicity to humans and livestock. Globally distributed, bloom-forming Planktothrix either retain or lose the mcy gene cluster (encoding synthesis of secondary metabolite hepatotoxin microcystin MC), resulting in a variable spatial/temporal distribution (non)toxic genotypes. Despite their importance human well-being, such genotype diversity is not being mapped at scales relevant nature. We aimed reveal...
The human health risks posed by exposure to cyanobacterial toxins such as microcystin (MC) through water and fish consumption remain poorly described. During the last two decades, coastal regions of Lake Victoria Nyanza Gulf (Kisumu Bay) have shown severe signs eutrophication with blooms formed Microcystis producing MC. In this study, spatial variability in MC concentration Kisumu Bay was investigated which mostly caused buoyancy wind drifting. Small (<6 cm) mainly composed Rastrineobola...