100 research outputs found
The microbiotest battery as an important component in the assessment of snowmelt toxicity in urban watercourses—preliminary studies
The aim of the study was to use a battery of
biotests composed of producers (Selenastrum
capricornutum, Sorghum saccharatum, Lepidium
sativum, and Sinapis alba), consumers (Thamnocephalus
platyurus), and decomposers (Tetrahymena thermophila)
to evaluate the toxicity of snowmelt and winter storm
water samples. The toxicity of the samples collected in
the winter period December to February (2010–2011), in
one of the largest agglomerations in Poland, the city of
Lodz, was compared to that of storm water samples taken
under similar conditions in June. The most toxic snowmelt
samples were found to be high acute hazard (class IV),
while the remaining samples were rated as slight acute
hazard (class II). L. sativum (in the Phytotox test) was the
most sensitive test organism, giving 27 % of all toxic
responses, followed by S. capricornutum with 23 % of
all responses. T. thermophila was the least sensitive, with
only 2 % of all toxic responses. The greatest range of
toxicity was demonstrated by samples from the single
family house catchment: no acute hazard (class I) to high
acute hazard (class IV
Bacteria homologus to Aeromonas capable of microcystin degradation
Water blooms dominated by cyanobacteria
are capable of producing hepatotoxins known as
microcystins. These toxins are dangerous to people and
to the environment. Therefore, for a better understanding
of the biological termination of this increasingly
common phenomenon, bacteria with the potential to
degrade cyanobacteria-derived hepatotoxins and the
degradative activity of culturable bacteria were studied.
Based on the presence of the mlrA gene, bacteria with a
homology to the Sphingopyxis and Stenotrophomonas
genera were identified as those presenting potential for
microcystins degradation directly in the water samples
from the Sulejów Reservoir (SU, Central Poland). However,
this biodegrading potential has not been confirmed in in
vitro experiments. The degrading activity of the culturable
isolates from the water studied was determined in more
than 30 bacterial mixes. An analysis of the biodegradation
of the microcystin-LR (MC-LR) together with an analysis of
the phylogenetic affiliation of bacteria demonstrated for
the first time that bacteria homologous to the Aeromonas
genus were able to degrade the mentioned hepatotoxin,
although the mlrA gene was not amplified. The maximal
removal efficiency of MC-LR was 48%. This study
demonstrates a new aspect of interactions between the
microcystin-containing cyanobacteria and bacteria from
the Aeromonas genus.The authors would like to
acknowledge the European Cooperation in Science
and Technology, COST Action ES 1105 “CYANOCOST -
Cyanobacterial blooms and toxins in water resources:
Occurrence, impacts and management” for adding value
to this study through networking and knowledge sharing
with European experts and researchers in the field. The
Sulejów Reservoir is a part of the Polish National Long-
Term Ecosystem Research Network and the European
LTER site
The microbiotest battery as an important component in the assessment of snowmelt toxicity in urban watercourses—preliminary studies
Toxic cyanobacteria in reservoirs in northeastern Brazil: detection using a molecular method
A European Multi Lake Survey dataset of environmental variables, phytoplankton pigments and cyanotoxins
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.g., anatoxin-a) and cytotoxins (e.g., cylindrospermopsin) due to their potency. Most studies examine the relationship between individual toxin variants and environmental factors, such as nutrients, temperature and light. In summer 2015, we collected samples across Europe to investigate the effect of nutrient and temperature gradients on the variability of toxin production at a continental scale. Direct and indirect effects of temperature were the main drivers of the spatial distribution in the toxins produced by the cyanobacterial community, the toxin concentrations and toxin quota. Generalized linear models showed that a Toxin Diversity Index (TDI) increased with latitude, while it decreased with water stability. Increases in TDI were explained through a significant increase in toxin variants such as MC-YR, anatoxin and cylindrospermopsin, accompanied by a decreasing presence of MC-LR. While global warming continues, the direct and indirect effects of increased lake temperatures will drive changes in the distribution of cyanobacterial toxins in Europe, potentially promoting selection of a few highly toxic species or strains.Peer reviewe
Aphanizomenon gracile (Nostocales), a cylindrospermopsin-producing cyanobacterium in Polish lakes
Data Descriptor : 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. Consistency in data collection and analysis methods is necessary to achieve fully comparable datasets and for statistical validity, avoiding issues linked to disparate data sources. The European Multi Lake Survey (EMLS) in summer 2015 was an initiative among scientists from 27 countries to collect and analyse lake physical, chemical and biological variables in a fully standardized manner. This database includes in-situ lake variables along with nutrient, pigment and cyanotoxin data of 369 lakes in Europe, which were centrally analysed in dedicated laboratories. Publishing the EMLS methods and dataset might inspire similar initiatives to study across large geographic areas that will contribute to better understanding lake responses in a changing environment.Peer reviewe
Assessment of heavy metals mobility and toxicity in contaminated sediments by sequential extraction and a battery of bioassays
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