Adam Latała

Toxicity of imidazolium and pyridinium based ionic liquids towards algae. Chlorella vulgaris, Oocystis submarina (green algae) and Cyclotella meneghiniana, Skeletonema marinoi (diatoms)

This paper reports on an investigation into the toxicity of 1-alkyl-3-methylimidazolium ionic liquids (ILs) towards two green algae (Chlorella vulgaris and Oocystis submarina) characteristic of freshwater and brackish environments, as well as two brackish and marine diatoms (Cyclotella meneghiniana and Skeletonema marinoi). The test kit of IL compounds consisted of five 1-alkyl-3-methylimidazolium chlorides (from -ethyl to -decyl) for evaluating the expected alkyl chain length effect, together with 1-butyl-3-methylimidazolium tetrafluoroborate, dicyanamide, trifluoromethanesulfonate, methyl sulfate an α-methyl[poly(oxy-1,2-ethanediyl)]sulfate for investigating the influence of the anion on IL toxicity towards various algal species. A pronounced alkyl chain effect was confirmed with all the organisms studied. EC50 values were linearly very well correlated with the number of carbon atoms in the IL alkyl chains. The results indicate that diatoms are far more sensitive than green algae to ILs. Cell size also plays an important part in the intoxication process: a tenfold difference in cell size results in a 100% more sensitive reaction to ionic liquids in both the green algae and diatoms. No significant differences were observed between alkylimidazolium salts and an alkylpyridinium compound of similar lipophilicity. It was also found that the use of tetrafluoroborate and trifluoromethanesulfonate as counteranions in the IL structure gave rise to the most pronounced toxic effects in comparison with the other anions tested. In the case of tetrafluoroborate this is probably caused by the potential hydrolysis of this entity, which leads to the formation of fluoride and a further increase in toxicity. Whereas in the case of trifluoromethanesulfonate it is likely caused by relatively high lipophilicity of this anion, additionally known to be strongly associated with alkylimidazolium cations, that in turn may enhance cell wall penetration.

Toxicity of imidazolium and pyridinium based ionic liquids towards algae. Bacillaria paxillifer (a microphytobenthic diatom) and Geitlerinema amphibium (a microphytobenthic blue green alga).

Many studies done so far on the aquatic ecotoxicity of ionic liquids have dealt with phytoplankton organisms. Nonetheless, benthic organisms are just as important if we are to fully understand the prospective fate and effects of ionic liquids in the aquatic environment. An investigation was therefore undertaken into the toxicity of 1-alkyl-3-methylimidazolium ionic liquids towards the diatom Bacillaria paxillifer and the cyanobacteriumGeitlerinema amphibium, species characteristic of the benthic environment. As in the first part of this study (A. Latala, M. Nedzi and P. Stepnowski, Green Chem., 2009, 11, 580–588), five 1-alkyl-3-methylimidazolium chlorides (from ethyl to decyl) were chosen as the test kit compounds for examining the expected alkyl chain length effect, together with 1-butyl-3-methylimidazolium tetrafluoroborate, dicyanamide, trifluoromethanesulfonate and methyl sulfate and α-methyl[poly(oxy-1,2-ethanediyl)]sulfate for investigating the influence of anions on the toxicity of ionic liquids towards the algal species under investigation. A pronounced alkyl chain effect was found with both organisms. The results indicate that P. amphibium is more sensitive than B. paxillifer. It was also found that the use of trifluoromethanesulfonate and dicyanamide as counteranions in the IL structure gave rise to the most pronounced toxic effects in comparison with the other anions tested. It is assumed that the greater toxicities of long alkyl chain ILs will most probably not pose a greater threat to benthic organisms, since these compounds will undergo rapid and very strong adsorption to sedimentary matter. Short-chain compounds, which are known to be reversibly bound to sediments, may still pose a significant risk to benthic ecosystems, however.

Toxicity of imidazolium ionic liquids towards algae. Influence of salinity variations

This paper reports on a detailed study of the influence of salinity on the biological activity of 1-alkyl-3-methylimidazolium chlorides on two green algae Oocystis submarina and Chlorella vulgaris, one diatom Cyclotella meneghiniana and one blue-green alga Geitlerinema amphibium. All these organisms inhabit the Baltic Sea, an environment naturally varying greatly in salinity. The toxicity effects of ILs towards cyanobacterial and algal organisms were tested in fresh water and in water of four different salinities—8, 16, 24 and 32 PSU—reflecting the whole range encountered in the Baltic Sea. Increasing the salinity was found to exert a significant influence on ionic liquid toxicity in all cases. The lower toxicity is probably due to the reduced permeability of ionic liquid cations through the algalcell walls. Higher chloride concentrations offer a good ion-pairing environment for imidazolium cations, which therefore compete with hydroxyl or silanol functional groups in cell-wall structures. The results of this work indicate that at higher salinities algalgrowth is inhibited to a significantly lesser extent. With the same IL concentration, the toxicity decreases by eight–ten times in the algae or about three times in the cyanobacterium in the 0–32 PSU salinity range.

Acute toxicity assessment of perfluorinated carboxylic acids towards the Baltic microalgae.

The presence of high-energy carbon-fluorine bonds in perfluoro compounds lends them great stability and causes them to be environmentally persistent. Relatively little is known about the acute toxicity of perfluorinated carboxylic acids (PFCAs) to ecotoxicological markers such as aquatic plants and animals. This study tested the toxicity of these compounds to the green alga Chlorella vulgaris, the diatom Skeletonema marinoi and the blue-green alga Geitlerinema amphibium, which are species representative of the algal flora of the Baltic Sea. The EC(50) values obtained range from 0.28 mM to 12.84 mM. A distinct relationship between hydrophobicity and toxicity is demonstrated. For every extra perfluoromethylene group in the alkyl chain, the toxicity increases twofold. LogEC(50) values are very well correlated linearly with both the number of carbon atoms in the perfluoroalkyl chain and the partition coefficients. The results also indicate that there are clear differences between the responses of particular taxonomic groups of algae: blue-green algae and diatoms are far more sensitive to PFCAs than green algae, probably because of differences in cell wall structure.

Comparative analysis of oxygen consumption rates between cupped oyster spat of Crassostrea gigas of French, Japanese, Spanish and Taiwanese origins

Respiration rates of various geographical strains of Crassostrea gigas were compared to assess the respiratory expenditure as a physiological indicator of catabolism (cost of maintenance). Parental oysters, sampled in France (Marennes-Oleron), Japan (Hiroshima), Taiwan (Tunkang) and Spain (Cadix), were differentiated by both their geographic origin and by mitochondrial DNA markers, allowing the distinction between the two cIosely related taxa Crassostrea gigas and Crassostrea angulata. After reproduction of these parental oysters, respiration rates of spat of each strain, reared under common controlled conditions, were individually estimated at 20 oC by using a volumetric microrespirometer. Our results demonstrated that physiological variability existed among the Crassostrea gigas strains and is likely to be related to physiological differences between geographical regions and/or genetic adaptations. The French strain showed the highest rates (0.71 IlL·h-I), while the Japanese, Taiwanese and the hybrid between Spanish and French strains consumed less, 0.53, 0.43 and 0.40 IlL·h-l, respectively. Our results confirmed the discrepancies previously suggested between Crassostrea gigas and Crassostrea angulata. Comprehensive physiological assessments should be carried out over a wide temperature range to confirm our results and to further evaluate growth potential. Appropriate decision making based on these studies will help future shellfish management in shellfish rearing areas such as the overstocked Marennes-Oleron Bay.

Photoacclimation strategies in the toxic cyanobacterium Nodularia spumigena (Nostocales, Cyanobacteria)

Jodłowska S. and Latała A. 2010. Photoacclimation strategies in the toxic cyanobacterium Nodularia spumigena (Nostocales, Cyanobacteria). Phycologia 49: 203–211. DOI: 10.2216/08-14.1. This ecophysiological study of the planktonic cyanobacterium strain Nodularia spumigena (BA-15) was conducted at three photosynthetic active radiation (PAR) irradiances (10, 150, and 290 µmol photons m−2 s−1) and two temperatures (15 and 30°C). The filament concentration, pigment composition, and photosynthetic performance of N. spumigena depended on culture conditions. The cyanobacterium was very tolerant of the highest irradiance at the lower temperature (15°C). Filament concentration, however, was lower at the higher temperature and the highest irradiance compared with other culture conditions. The efficiency (α) and maximum rates of photosynthesis (Pm) were both affected negatively at 30°C under irradiances of 150 and 290 µmol photons m−2 s−1. The photoacclimation capacity of the cyanobacterium was evaluated by analysing pigment concentration (chlorophyll, carotenoids, phycobilins), the photosynthetic light response curves (P-E), and chlorophyll a fluorescence. The highest concentrations of phycobilins and chlorophyll a per 100 µm of filament were observed at 10 µmol photons m−2 s−1 and the lowest at 290 µmol photons m−2 s−1. Two photoacclimation mechanisms were identified in N. spumigena based on P-E, namely, changes in the number of photosynthetic units and changes in size. The minimum value of Pc (about 5 µmol photons m−2 s−1) and Ps (about 150 µmol photons m−2 s−1) is close to those reported for shade-tolerant plants, while the maximum value of Pc (about 100 µmol photons m−2 s−1) and Ps (about 400 µmol photons m−2 s−1) is close to those noted in heliophylous plants. Fluorescence measurements of N. spumigena indicated that high irradiance had a negative effect on both Fv/Fm and ΦPSII, but the effect was more pronounced in the case of ΦPSII. The tolerance of this planktonic cyanobacterium to elevated light levels explains to some degree why it occurs regularly in marine waters worldwide in summer and often forms toxic blooms.

Morphological and molecular phylogenetic studies on Fistulifera saprophila

Accurate taxonomic identification provides the foundation for a number of diatom applications, such as the ecological monitoring of waters and the reconstruction of past environments. Despite significant recent developments in diatom taxonomy and phylogenetics, to date, only a few taxa have been studied extensively using a wide range of techniques. In this paper, data gained from intensive research on the morphology of live and cleaned diatom cells of two Fistulifera saprophila (Lange-Bertalot & Bonik) Lange-Bertalot strains isolated from the Gulf of Gdańsk are discussed. This study suggests that because specimens of F. saprophila have very delicate frustules prone to dissolution, the species has not been fully investigated and, therefore, a revised description is presented. Data on live cells and colony morphology, as well as interesting findings on the discrepancies between measurements of wet-mounted, dried and Naphrax-mounted diatom cells are also shown. The geographical distribution and ecological tolerance of F. saprophila is probably much wider than previously reported, but needs further investigation. The results of molecular phylogenetic analyses confirm the clear separation of Fistulifera Lange-Bertalot from Navicula Bory, also showing that its sister genera are Craticula Grunow, Eolimna Lange-Bertalot and Stauroneis Ehrenberg. Surprisingly, genera considered to have similar morphological characteristics, such as Mayamaea Lange-Bertalot and Sellaphora Mereschkowsky fall on a separate phylogenetic branch.

Bioaccumulation of 1-butyl-3-methylimidazolium chloride ionic liquid in a simple marine trophic chain

This study focused on the bioaccumulation intensities of the ionic liquid (IL) 1-butyl-3-methylimidazolium chloride (bmimCl) by two invertebrates: Mytilus trossulus and Balanus improvisus and the green alga Chlorella vulgaris. The bioconcentration of bmimCl by two invertebrates was tested in the contaminated water, both with and without the presence of green algae previously exposed to the bmimCl. The experimentally obtained bioconcentration factors (BCFs) are quite low and do not exceed the value of 10. The presence of contaminated C. vulgaris in the water induces an increase in BCF of barnacles up to 80% in comparison to barnacles exposed only to contaminated water. Detoxication of M. trossulus may be more effective in the presence of higher IL concentrations. BCFs for hard tissues of the mussel indicates an exclusively physical sorption mechanism on the mineral surface.

Mechanisms of Photoacclimation on Photosynthesis Level in Cyanobacteria

Cyanobacteria are oxygenic photoautotrophic prokaryotes, which develop in many aquatic environments, both freshwater and marine. They successfully grow in response to increasing eutrophication of water, but also because of shifts in the equilibrium of ecosystems (Stal et al., 2003). Cyanobacteria possess many unique adaptations allowing optimal growth and persistence, and the ability to out-compete algae during favorable conditions. For instance, many species are buoyant due to the possession of gas vesicles, some of them are capable of fixing N2, and unlike algae, which require carbon dioxide gas for photosynthesis, most cyanobacteria can utilize other sources of carbon, like bicarbonate, which are more plentiful in alkaline or high pH environments. The cyanobacteria live in a dynamic environment and are exposed to diurnal fluctuations of light. Planktonic species experience differences in irradiance when mixed in the water column (Staal et al., 2002), whereas mat-forming cyanobacteria are exposed to changes in light intensity caused by sediment covering or sediment dispersion. Such rapidly changing environmental factors forced photoautotrophic organisms to develop many acclimation mechanisms to minimize stress due to low and high light intensities. High irradiance may damage photosynthetic apparatus by photooxidation of chlorophyll a molecules. Some carotenoid pigments may provide effective protection against such disadvantageous influence of light (Hirschberg & Chamovitz, 1994; Steiger et al., 1999; Lakatos et al., 2001; MacIntyre et al., 2002). Photosynthetic organisms respond to decreased light intensity by increasing the size or/and the number of photosynthetic units (PSU) whose changes, in turn, can be reflected in characteristic patterns of P-E curves (Platt et al., 1980; Prezelin, 1981; Ramus, 1981; Richardson et al., 1983; Henley, 1993; Dring, 1998; Mouget et al., 1999; MacIntyre et al., 2002; Jodlowska & Latala, 2010). Variation in α and Pm (expressed per biomass or per chlorophyll a unit) plays a key part in interpreting physiological responses to changes in environmental conditions. The aim of this review was to present exceptional properties of two different cyanobacteria, planktonic and benthic, their abilities to changing environmental condition, especially to irradiance. This information would be helpful in understanding the phenomenon of mass formation of cyanobacterial blooms worldwide, and would be very useful to interpret the domination of cyanobacteria in water ecosystem in summer months.

Allelopathic and Bloom-Forming Picocyanobacteria in a Changing World

Picocyanobacteria are extremely important organisms in the world’s oceans and freshwater ecosystems. They play an essential role in primary production and their domination in phytoplankton biomass is common in both oligotrophic and eutrophic waters. Their role is expected to become even more relevant with the effect of climate change. However, this group of photoautotrophic organisms still remains insufficiently recognized. Only a few works have focused in detail on the occurrence of massive blooms of picocyanobacteria, their toxicity and allelopathic activity. Filling the gap in our knowledge about the mechanisms involved in the proliferation of these organisms could provide a better understanding of aquatic environments. In this review, we gathered and described recent information about allelopathic activity of picocyanobacteria and occurrence of their massive blooms in many aquatic ecosystems. We also examined the relationships between climate change and representative picocyanobacterial genera from freshwater, brackish and marine ecosystems. This work emphasizes the importance of studying the smallest picoplanktonic fractions of cyanobacteria.