Short Term Scientific Missions

STSM posters

Characterization and re-evaluation of selected Pseudanabaenaceae and Leptolyngbyaceae strains using polyphasic approach

by Boris Aleksovski, M.S

OBJECTIVES

In the present study we have characterized 9 new strains of Pseudanabaena isolated from Polar Regions, and we made re-evaluation of 15 selected members of Pseudanabaenaceae and Leptolyngbyaceae families present in culture collections, on the basis of combined molecular and cytomorphological markers.

 

RESULTS

Our results confirmed that the molecular evaluation of the selected strains more or less coincide with some morphological characters of the species, but unfortunately it seems that some other markers which are not that distinct and recognizable are more important for the taxonomic classification instead of the proposed ones.

Methods in genotoxicity testing of cyanobacteria and their metabolites

by Michal Bittner
Brno

 

VIDEO

Objectives

I)Single cell gel electrophoresis, Comet assay (reveals single and double strand breaks, alkali-labile sites, DNA–DNA/DNA–protein cross-links and single strand breaks associated with incomplete excision repair).

II)Micronucleus test (biomarker of effect, relevant for risk assessment of cancer).

III)Practical genotoxicity testing of cyanobacterial samples using upper mentioned methods.

 

 Results of Comet assay shown as percentage of tail DNA. PC – positive control B[a]P, SC – solvent control MeOH.

Degradation of cyanobacterial metabolites (taste and odor compounds) using Advanced Oxidation Processes (AOPs)

by Christophoros Christophoridis
Democritus University of Thrace

VIDEO

 

Objectives

•The evaluation of selected taste and odor compound removal using advanced oxidation processes.

•The optimization of working conditions of the reactors for the maximum degradation of target compounds and their transformation by-products.

•The determination and structure elucidation of transformation by-products using SPME-GC-MS, LC-MS

Highlights

•An analytical method for the simultaneous determination of taste and odor compounds was developed using SPME-GC/MS.

•Ozone treatment successfully degraded all compounds under 45 minutes of reaction

•pH and ozone concentration were the main factors affecting ozonation

•Kinetic parameters were calculated for both ozonation and UV/peroxide treatment

•More than 4 transformation products were identified for each compound.

Methods in laboratory cultivation, isolation and characterization of cyanobacteria and their metabolites

by Jano PRIEBOJOVA
Brno

Results

In selected species,  we found just in case of Microcystis aeruginosa 2 bands in the gel.

We repeated the PCR many times, but we didn´t obtained the results that we got first time.

We found the missing information about length of amplicons.

Highlights

The primers selected for this work, mastermix calculation and PCR conditions, were designed on these two articles.

Can the akinets survive to digestion of Daphnia magna Straus, 1920?

by Lorena Lago Meijide
Clermont-Ferrand

Objectives
During sedimentation, part of the annual life cycle of Nostocal group, the filaments fragmentation and the akinets sedimentation offer an opportunity for zooplankton to grazing. This STSM aims to test the akinets resistance against  digestion of a cladocera organism: Daphnia magna Straus, 1920.

 

Highlights
The grazing impact on akinets could be considered high because almost all akinets which were ingested were digested. However, if we consider the percentage ingested, the impact on natural akinets could be not significative.

Cyanotoxins and other non-ribosomal peptides in cyanobacteria populations of the shallow hypertrophic lake.

by Jurate Karosiené
Gdansk, Lithuania

The aim of the STSM is to analyze spatial and temporal variations of cyanotoxins and other nonribosomal
peptides in hypertrophic shallow lake and to determine possible toxin producers.
 


HIGHLIGHTS

• Cyanobacteria populations especially Planktothrix agardhii, Microcystis viridis, M. wesenbergii
and M. aeruginosa from the studied lake were rich in cyanopeptides.
Aphanizomenon gracile was responsible for saxitoxins synthesis in the lake. Microcystis viridis
and Planktothrix agardhii strains have been shown to produce microcystins.
Microcystis viridis synthesized a great variety of microcystins variants.
 

The expansion of Dolichospermum lemmermannii to the deep lakes south of the Alps: toxic potential and distribution pattern in the European context

by Camilla Capelli
Oslo, San Michele all’Adige

Dolichospermum lemmermannii represents a case of very recent colonization of cyanobacteria in the deep lakes south of the Alps. Indeed it occurred in the form of extended blooms for the first time in Lake Garda at the beginning of the 1990s, and then, in lakes Iseo (second half of the 1990s), Maggiore (2005), and Como (2006).

 

Highlights

Despite the genetic differences observed in the D. lemmermannii strains, this preliminary analysis did not allow to disclose a geographical distribution pattern driven by latitudinal/climatic gradients. However, the greater genetic homogeneity found in the populations living in the deep subalpine lakes suggest a strong founder effect following the establishment of Dolichospermum in this district.

Treatment of cyanobacterial cell extracts with advanced oxidation processes (AOPs): Kinetics and toxicity studies

by Maria G. Antoniou
Cyprus, Robert Gordon University

Highlights

• The pigments acted as photosensitizers in the presence of UVA radiation and caused removal of cyanotoxins except for CYN.

• Susceptibility of the cyanotoxins towards PCO treatment vary significantly due to their structural differences. Though MC-LR and d-MC-RR belong to the same group of
cyanotoxins, d-MC-RR was less susceptible to AOP treatment possibly because of shielding effects caused by the two arginine (R) groups in its structure.

• Catalyst addition (TiO2) did not enhance toxin removal compared to photolysis possibly due to radical consumption by the matrix (pigments).

• Toxicity studies based on the inhibition of the PP1 enzyme showed no reduction of toxicity after 60 min of treatment because the remaining toxin concentration was still high enough to
cause almost complete inhibition of the enzyme’s activity (IC50=7,4 μg/L).

Effects of different degrading species on 2-methylisoborneol and geosmin during γ-radiolysis of water

by Carlos J. Pestana

Results

A total of 18 degradation products have been identified for MIB and 32 for geosmin. It has been shown that the oxidative pathway (via OH·) and the reductive pathway (via eaq-) differ in the degradation of MIB, the oxidative pathway proceeds via the production of camphor, while the reducing pathway proceeds via the production of fenchyl alcohols. As for geosmin, the oxidative appears to proceed via an initial ringopening followed by a second ring opening, arriving at a linear structure. This process appear similar in both the oxidative and reductive degradation pathway.

Nostoc edaphicum a rich source of bioactive peptides

by Hanna Mazur-Marzec
Gdansk

VIDEO

 

Results

As a result of the pilot experiment conducted with the application of Nostoc edaphicum CCNP1411, eight pooled fractions, ten fractions containing isolated peptides classified to cyanopeptolins (purity > 95%) and approx. 30 fractions containing a mixture of 2-3 peptides  were collected. Several fractions contained different analogues of peptides classified to nostocyclopeptides. In the case of three pooled fractions, the MTT assay revealed cytotoxic activity.

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