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The consumption of seafood containing marine biotoxins called ciguatoxins (CTXs) can result in ciguatera poisoning (CP), a globally prevalent seafood-born human illness. Since 2015 isolated and mass outbreaks of CP have occurred along the southwestern coast of India, however, no attributable CTXs have yet been identified. Herein, several CTXs are described in an often marketed snapper species (Lutjanus bohar) from southwest India. CTX3C-group compounds were identified by LC-MS/MS with a toxicity range of 0.79-5.39 ng CTX3C equivalent (eq.) g-1 wet tissue eq., as determined by an in vitro cell (Neuro-2a) assay. Samples investigated were part of a 7,000 kg international shipment of frozen snapper product imported into the European Union and subsequently implicated in a 2020 CP outbreak in the Netherlands. The identification of CTX3C-group toxins in fish originating from coastal India suggests a re-evaluation of the current understanding of CTXs associated CP with seafood from the Indian Ocean region.

Chemical degradation of lignin has attracted increasing interest due to its potential for producing chemicals from renewable resources. Herein, we present a new transition metal free degradation procedure utilizing DDQ-oxidation and boryl radical mediated degradation, followed by reconnection of a monomer intermediate to a new dimer in a domino process. Our results include the selective degradation of oxidized β-O-4 model compounds by a boryl radical initiated with a catalytic amount of 4-(4-pyridinyl)benzonitrile and bispinacolborane B2(pin)2 as well as its application to organosolv lignin. This sequential procedure expands the toolbox for lignin degradation from simple depolymerization to high-value products by incorporating bond forming transformations within the process, and also provides a new transition-metal free method for the construction of 1,6-diketone fragments.

Ciguatoxins (CTXs) are polyether marine biotoxins that can cause ciguatera poisoning (CP) after the consumption of fish or invertebrates containing sub ppb levels, concentrations that present a challenge for current extraction and analysis methods. Here, a newly developed and (partly) validated single-day extraction protocol is presented. First, the fish sample is broken-down by enzymatic digestion, followed by extraction and extract clean-up by defatting and two solid-phase extractions. Final extracts were investigated using two different CTX-analysis methods, an in vitro cytotoxicity assay (N2a-assay) and by LC-MS/MS. Validation was performed for both fillet and freeze-dried samples of snapper, parrotfish, and grouper spiked with CTX1B, 52-epi-54-deoxyCTX1B, 54-deoxyCTX1B, and CTX3C. Based on recovery rates (35–88%) and matrix effects (66–116%) determined by LC-MS/MS, the enzyme protocol is applicable to various matrices. The protocol was applied to naturally contaminated fish tissue (Lutjanus bohar) obtained during a CP incident in Germany. Several potential CTX congeners were identified by a two-tier LC-MS/MS approach (screening of sodium adducts, high-resolution or low-resolution confirmation via ammonium adducts). Inclusion of &gt, 30 known CTX congeners into the LC-MS/MS methods and single-day sample preparation make the method suitable for analysis of ciguatera suspect samples at sub ppb levels also with undisclosed CTX profiles.

Globally, the livelihoods of over a billion people are affected by changes to marine ecosystems, both structurally and systematically. Resources and ecosystem services, provided by the marine environment, contribute nutrition, income, and health benefits for communities. One threat to these securities is ciguatera poisoning; worldwide, the most commonly reported non-bacterial seafood-related illness. Ciguatera is caused by the consumption of (primarily) finfish contaminated with ciguatoxins, potent neurotoxins produced by benthic single-cell microalgae. When consumed, ciguatoxins are biotransformed and can bioaccumulate throughout the food-web via complex pathways. Ciguatera-derived food insecurity is particularly extreme for small island-nations, where fear of intoxication can lead to fishing restrictions by region, species, or size. Exacerbating these complexities are anthropogenic or natural changes occurring in global marine habitats, e.g., climate change, greenhouse-gas induced physical oceanic changes, overfishing, invasive species, and even the international seafood trade. Here we provide an overview of the challenges and opportunities of the 21st century regarding the many facets of ciguatera, including the complex nature of this illness, the biological/environmental factors affecting the causative organisms, their toxins, vectors, detection methods, human-health oriented responses, and ultimately an outlook towards the future. Ciguatera research efforts face many social and environmental challenges this century. However, several future-oriented goals are within reach, including digital solutions for seafood supply chains, identifying novel compounds and methods with the potential for advanced diagnostics, treatments, and prediction capabilities. The advances described herein provide confidence that the tools are now available to answer many of the remaining questions surrounding ciguatera and therefore protection measures can become more accurate and routine.

Veterinary antibiotics are frequently applied in livestock farming worldwide and their usage is expected to increase during the next years by more than 60%. The aim of this review is to give a brief overview about excretion rates reported for diverse antibiotics and their fate within different manure treatments. Depending on the substance, 99%). Based on reported transformation products of distinct antibiotics, degradation cannot be presumed for most compounds. In many cases, only minor structural modifications were observed and several transformation products are still microbiologically active. Consequently, manure treatments should not be evaluated based on the disappearance of the parent compound only. Comprehensive studies should include the elucidation of elimination pathways to identify efficient processes for reducing the input of antibiotics into the environment.

The impressive ability of the fungus Xylaria longipes to transform the highly persistent fluoroquinolone ciprofloxacin into microbiologically less active degradation products was demonstrated. Fluoroquinolones are used extensively in both human and veterinary medicine. Poor metabolization and high chemical stability of these synthetic antibiotics led to their presence in several environmental compartments. This undesirable behavior may promote the spread of resistance mechanisms due to concomitant exposure to bacteria. Therefore, the biotransformation of ciprofloxacin, one of the most prescribed fluoroquinolones in human medicine, by the ascomycetous soft rot fungus X. longipes was investigated in detail. Submerged cultivation of the fungus allowed for high-yield formation of four biotransformation products. These compounds were subsequently purified by preparative high-performance liquid chromatography. Applying accurate mass spectrometry and nuclear magnetic resonance spectroscopy, desethylene-ciprofloxacin, desethylene-N-acetyl-ciprofloxacin, N-formyl-ciprofloxacin and N-acetyl-ciprofloxacin were unambiguously identified. N-acetylation and N-formylation of the drug led to a 75-88% reduction of the initial antibacterial activity, whereas a breakdown of the piperazine substituent resulted in almost inactive products. These findings suggest an important role in the inactivation and degradation of this and other synthetic compounds in the environment.

Ergosterol, a precursor of vitamin D(2), is present in the cell membrane of all fungi. It can be transformed into vitamin D(2) by UV-B exposure. In this study, a basidiomycete, Pleurotus sapidus, cultivated in liquid malt extract medium was exposed to UV-B light. In addition, autoclaved, abiotic mycelium was put through UV-B exposure for the first time. The effects of different UV-B exposure times, surface areas and temperatures on vitamin D(2) formation were analyzed. The conversion of ergosterol to vitamin D(2) at ambient temperature almost reached completion within 10 min resulting in vitamin D(2) concentrations of 365 µg (g dry matter)(−1). Prolonged exposure of the biotic mycelium for up to 60 min resulted in a reduced vitamin D(2) concentration with stagnation at about 280 µg (g dry matter)(−1). Exposure of the abiotic mycelium showed a slower increase but also leveled off at the same concentration. Furthermore, it could be shown that vitamin D(2) formation depends on the temperature and the exposed surface area. The vitamin D(2) concentration augmented after increasing the exposed surface from 65.0 to 298.6 cm(2). The ergosterol content of P. sapidus was analyzed in a way similar to vitamin D(2) and resulted in 3.75 ± 0.06 mg (g dry matter)(−1) ergosterol. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1007/s13197-018-3290-z) contains supplementary material, which is available to authorized users.

Veterinary antibiotics such as sulfonamides are frequently applied in livestock farming worldwide. Due to poor absorption in the animal gut and/or reversible metabolization sulfonamides are excreted in considerable amounts and can subsequently be detected in liquid manure. As manure is utilized for soil fertilization, sulfonamides can enter the environment via this pathway. Water samples taken below an agriculture field in Lower Saxony revealed the permanent entrance of sulfamethazine into groundwater and concentrations up to 100 ng L−1 were determined. During a long-term lysimeter study, nine sulfonamides were applied to two different soil types by using fortified liquid manure. Divert mobilities were found with sulfamethazine und sulfamethoxazole showing the highest detection frequency in water samples taken below both bedrock and sandy soil. Four years after the last application of fortified manure, sulfonamides were still detectable in the leachate. Based on analyses of manure and fermentation residue samples, a permanent input of sulfonamides to the soil can be excluded. Thus, the positive findings must be caused by the antibiotics once applied. Soils fertilized with manure contaminated with sulfonamides can consequently be a long-time source for the transfer of antibiotics into groundwater.

Liquid manure is frequently used as soil fertilizer due to its high nutrient content. It can also contain residues of pharmaceuticals, such as antibiotics, if farm animals are medicated. The anaerobic fermentation process in biogas plants is discussed as one way to reduce the input of antibiotics into the environment. Therefore, 10 worldwide-applied sulfonamides (sulfachloropyridazine, sulfadiazine, sulfadimethoxine, sulfaguanidine, sulfamerazine, sulfamethazine, sulfamethoxazole, sulfamethoxypyridazine, sulfapyridine, and sulfathiazole) and four frequently used tetracyclines (chlortetracycline, doxycycline, oxytetracycline, and tetracycline) were investigated concerning their elimination pattern during anaerobic fermentation. Batch fermenters with autoclaved and non-autoclaved inoculum were utilized to distinguish between biotic and abiotic elimination pathways. Overall, sulfadimethoxine, sulfamethoxypyridazine, and sulfamethoxazole showed the highest elimination, which was considerably reduced by autoclaving before inoculation. Structure elucidation via nuclear magnetic resonance and different mass spectrometry techniques revealed only minor structural modifications such as O-demethylation and hydrogenation, which did not result in a considerably reduced antimicrobial activity. These results show that, especially, sulfonamides are more persistent than expected. Future studies should deal with the elucidation of relevant process parameters for an enhanced compound degradation.

Twenty-nine basidiomycetes were screened in surface and liquid cultures for their capability to biotransform the chloroacetamide herbicide Dimethenamid-P (DMTA-P). The basidiomycete Irpex consors converted 70% of the herbicide (0.5 g L-1 DMTA-P) in liquid cultures within 6 days, applying a minimal medium under non-ligninolytic conditions. Nine transformation products of DMTA-P were identified by liquid chromatography-mass spectrometry analysis of the culture supernatants. The four main metabolites were isolated and subjected to GC-MS analysis and NMR spectroscopy. The analyses revealed that the thiophene ring was oxidized at three different positions. Metabolite M1 was identified as the S-oxide, which was isolable and relatively stable at room temperature. In metabolite M2, one methyl substituent of the thiophene ring was hydroxylated. The two metabolites M3A and M3B were diastereomers, but fully separated by HPLC. Here, oxidation of the aromatic CH carbon resulted in prototropic rearrangement to an αβ-unsaturated thiolactone. None of the three major metabolites of DMTA-P has been described before.

Tetracyclines belong to the group of the most applied antibiotics in veterinary medicine worldwide. Due to their incomplete absorption and/or metabolism in the animal gut, tetracyclines are frequently detected in manure samples. Within the matrix, an elimination of these compounds has been reported in several studies. However, only little information about potential transformation products of tetracyclines in manure and the environment is available. Therefore, the fate of tetracycline (TC) and chlortetracycline (CTC) was investigated in aqueous solutions and manure. Abiotic incubation of TC in phosphate buffer led to a remarkable red-brown coloring of the solution. Subsequent compound isolation and structure elucidation by MS/MS and NMR techniques revealed the formation of seco-cycline A, a compound formerly described as a fungal biotransformation product of TC. For CTC, two comparable products were identified which were derived from its isomeric form isoCTC. All transformation products showed no antimicrobial activity for concentrations up to 500 mg L−1. When TC and CTC were incubated in cow manure for 7 d, the above mentioned three transformation products were also formed in this complex matrix (up to 5.1 mg kg−1). Manure, soil and leachate samples from Lower Saxony revealed the presence of seco-cycline A in manure and soil, but not in water. To obtain a better insight in the fate of tetracyclines in environmental matrices, future analytical and ecotoxicological studies dealing with this subject should include the analysis especially of seco-cycline A.

Purpose To conceptualize the journey that veterinary antibiotics (VAs) follow between the animal stall and the field, two experiments were conducted. (1) The VAs sulfadiazine, sulfamethazine, sulfamethoxazole and tetracycline were mixed into cow excrement; prepared with three dry solid content variations. (2) Cow excrement containing the same VAs was mixed into sandy and clayey saturated soils. The aim was to quantify the solid-liquid partitioning and time-dependent behaviour of VAs at each stage of the journey, to enable mathematical replication of the process in the future.

Purpose The aim of this study was to assess if veterinary antibiotics, which are introduced to agricultural fields via fertilizer, are present in water systems (in both water and sediment) followingoverlandtransport viarunoffandsoilerosion. Materials and methods Three water and sediment sampling schemes were conducted in Germany between June 2013 and June 2014 to examine the effects of (1) season, (2) heavy rainfall and (3) high veterinary antibiotic usage. The samples were analysed for 15 veterinary antibiotics using liquid chromatography tandem mass spectrometry. Results and discussion Antibiotics were detected in all three schemes in trace quantities. This is the first time that veterinary antibiotics have been detected in German sediment. Conclusions In particular, the presence of tetracycline in sediment taken from irrigation ditches in an agricultural area of high veterinary antibiotic usage offers proof that the overland transport of veterinary antibiotics is occurring. Due to the strong sorption of veterinary antibiotics (particularly tetracyclines) to soils, further research into their transport via soil erosion and assessment of their presence in sediment is advised.

Extensive usage of fluoroquinolone antibiotics in livestock results in their occurrence in manure and subsequently in the environment. Fluoroquinolone residues may promote bacterial resistance and are toxic to plants and aquatic organisms. Moreover, fluoroquinolones may enter the food chain through plant uptake, if manure is applied as fertilizer. Thus, the presence of fluoroquinolones in the environment may pose a threat to human and ecological health. In this study, the biotransformation of enrofloxacin, marbofloxacin, and difloxacin by the fungus X. longipes (Xylaria) was investigated. The main metabolites were unequivocally identified as the respective N-oxides by mass spectrometry and nuclear magnetic resonance spectroscopy. Fungal-mediated N-oxidation of fluoroquinolones led to a 77-90% reduction of the initial antibacterial activity. In contrast to their respective parent compounds, N-oxides showed low cytotoxic potential and had a reduced impact on cell proliferation. Thus, biotransformation by X. longipes may represent an effective method for inactivating fluoroquinolones.

Pharmaceuticals are widely distributed in low concentrations in the water compartment. Conventional sewage treatment plants (STP) are not capable to remove pharmaceuticals to the full extent, so alternative methods such as ozonization or photooxidation are tested as additional stage. However, it has been shown that in many cases no complete mineralization is achieved during these processes and transformation products occur. Up to now only little is known about these transformation products in terms of their structure and toxicity. The antibiotic sulfathiazole (STZ) is used in veterinary medicine and it can be detected in different water matrices such as STP effluent or surface water. We tested the ability of photooxidation for degradation of STZ using a medium pressure mercury lamp. LC-UV showed the formation of several minor compounds and one main transformation product which has been isolated subsequently. Using NMR and high resolution mass spectrometry techniques, we were able to reveal the structure of promizole, an antituberculotic, used in the 1950s. This compound showed a reduced microbial activity in Brilliant Black Reduction Maximum Residue Level test. Furthermore, there was no difference in the effects of promizole when compared to STZ on cell toxicity and cell proliferation in two murine cell lines.

Tetracyclines and sulfonamides are among the most commonly applied antibiotics in veterinary medicine and can be frequently detected in manure samples worldwide. The treatment of contaminated manure within the anaerobic digestion process of biogas plants is often discussed as possible route for the degradation of antibiotics. To test this assumption, various parameters of the anaerobic fermentation process (temperature, addition of cellulolytic enzymes, separate hydrolysis unit) were investigated concerning their impact on the elimination of four commonly used veterinary antibiotics (sulfadiazine, sulfamethazine, tetracycline and chlortetracycline). Elimination rates of the antibiotics varied between 17% and 88% with chlortetracycline showing the highest rates due to the pH-mediated formation of iso-chlortetracycline. Based on the various experimental approaches, abiotic processes such as sorption rather than biotic transformation were considered as relevant elimination pathways. Therefore, sorption studies were carried out in liquid digestate matrix with varying amounts of solid matter. A (significantly) increased compound elimination with increasing solid matter amount was found. Furthermore, it was proven that the antibiotics can desorb again from the solids. Consequently, anaerobic fermentation should not generally be regarded as effective tool of reducing the release of antibiotics into the environment.

Dimethylsulfoniopropionate (DMSP), a sulfur containing osmolyte and antioxidant, is suggested to take over the role of nitrogen-containing osmolytes under nitrate-depleted conditions. But other factors like time of day or limitation by nutrients can influence the cellular DMSP content as well. Especially in diatoms the complex dynamics of this central metabolite are still poorly understood. Therefore, we monitored the DMSP content in batch cultures of the diatom Skeletonema marinoi over the entire culture development, using a detailed sampling protocol on a diurnal basis to investigate the influence of the day/night cycle and limitation by nitrogen and other nutrients on cellular DMSP. Cultures were inoculated with initial high nitrate (N +) or low nitrate (N −) concentrations to evaluate the effects of nitrogen availability. The DMSP content per cell varied significantly with a 4-fold increase over the entire experiment. For N + conditions a pronounced diurnal pattern was found with increasing DMSP contents per cell during the light and decreasing DMSP contents during the dark period. However, when DMSP was normalized to cell volume, the highest concentrations occurred near the beginning of the light period. For N − cultures no such pronounced pattern was found. DMSP values of N − cultures increased within a few hours after the medium became nitrate depleted, while no such connection between nitrogen-concentration and DMSP could be observed in the N + cultures, where possibly an overflow mechanism or limitation of other nutrients such as Si might affect DMSP concentrations. Based on this data set we can conclude that DMSP formation in S. marinoi is under a pronounced diurnal control and depends in a rather complex manner on other factors such as growth limitation by nutrients.

Dimethylsulfoniopropionate (DMSP) is a metabolite involved in central processes of phytoplankton physiology and ecology. Due to its high abundance, this molecule plays also a major role in global sulfur cycling. DMSP concentrations are usually indirectly determined via the base mediated release of dimethylsulfide (DMS) using gas chromatography (GC). However, because other potential precursors of DMS have been reported from macroalgae and phytoplankton, there is a substantial risk for an overestimation using an indirect method. We improve and validate a protocol for the derivatization and determination of DMSP in phytoplankton cultures. The improved method includes derivatization with 1-pyrenyldiazomethane (PDAM) and analysis via ultra performance liquid chromatography coupled with a mass selective detector (UPLC/MS). The protocol allows simultaneous qualitative and quantitative analysis of DMSP, other putative DMS precursors and osmolytes like glycine betaine (GBT). Detection limits are around 100 fmol on column allowing the quantification of DMSP from plankton field samples as well as from phytoplankton cultures. The DMSP content of several phytoplankton cultures was determined using the method involving derivatization of DMSP as well as an indirect headspace method determining DMS. For several algae strains, significant higher concentrations were obtained with the indirect determination. These results underscore the importance of other potential DMS precursors in phytoplankton samples that are not considered when using indirect methods for DMSP determination.

A simple, derivatization free method for the direct determination of dimethylsulfoniopropionate (DMSP) using hydrophilic interaction liquid chromatography (HILIC)/mass spectrometry is introduced. DMSP is a zwitterionic osmolyte which is produced from marine plankton, macro algae and higher plants. Due to its central role in climate relevant geochemical processes as well as in plant physiology and chemical ecology there is a great interest in methods for its quantification. Since DMSP is labile and difficult to extract currently most protocols for quantification are based on indirect methods. Here we show that ultra performance liquid chromatography/mass spectrometry using a HILIC stationary phase is suitable for the direct quantification of DMSP from aqueous samples and microalgal extracts. The protocol requires minimal sample preparation and phytoplankton samples can be investigated after filtration of small volumes. The limit of detection is 20 nM and the calibration curve is linear in the range of 60 nM to 50 μM. The use of [2H6]-DMSP as internal standard allows prolonged sample storage since it is transformed with the same kinetics as natural DMSP. This makes the method suitable for both laboratory and field studies.

4-Vinylsyringol, also referred to as canolol, is a highly active antioxidant and potent lipidperoxyl radical scavenger found in rapeseed. The canolol content of rapeseed can be increased through the decarboxylation of sinapic acid via roasting treatments. Different roasting conditions were tested and compared and an optimum for the canolol formation was found at 160 °C. The canolol content of the rapeseed samples with optimal roasting increased by a factor of 120 in relation to the unroasted sample. The rapeseed was ground, extracted and analysed by normal-phase HPLC/UV. The structure of canolol was confirmed by NMR and MS techniques. Several rapeseed oils were purchased in German food stores and analysed. No differences in canolol content were observed in both cold-pressed and rape kernel oil samples tested. Dehulled rapeseed samples demonstrated no significant difference in canolol content when compared to unpeeled rapeseed samples.

Fluoroquinolones are considered as critically important antibiotics. However, they are used in appreciable quantities in veterinary medicine. Liquid manure and feces can contain substantial amounts of unmetabolized antibiotics and, thus, antibiotics can enter the environment if manure is used for soil fertilization. In this study, the microbial biotransformation of the synthetic veterinary fluoroquinolone danofloxacin by the ascomycete Xylaria longipes was investigated. Fungal submerged cultures led to a regioselective and almost quantitative formation of a single metabolite within 3 days. The metabolite was unequivocally identified as danofloxacin N-oxide by high-resolution mass spectrometry and one- and two-dimensional nuclear magnetic resonance spectroscopic techniques. An oxidation of the terminal nitrogen of the substituted piperazine moiety of the substance led to a remarkable reduction of 80% of the initial antibacterial activity. Thus, fungal enzymes involved in the biotransformation process might possess the potential to reduce the entrance of antibiotics via biotransformation of these compounds.

Antibiotics such as sulfonamides and tetracyclines are frequently used in veterinary medicine. Due to incomplete absorption in the animal gut and/or unmetabolized excretion, the substances can enter the environment by using manure as soil fertilizer. The anaerobic fermentation process of biogas plants is discussed as potential sink for antibiotic compounds. However, negative impacts of antibiotics on the fermentation process are suspected. The elimination of sulfadiazine, sulfamethazine, tetracycline and chlortetracycline in semi-continuous lab-scale fermenters was investigated. Both biogas production and methane yield were not negatively affected by concentrations up to 38 mg per kg for sulfonamides and 7 mg per kg for tetracyclines. All substances were partly eliminated with elimination rates between 14% and 89%. Both matrix and structure of the target molecule influenced the elimination rate. Chlortetracycline was mainly transformed into iso-chlortetracycline. In all other cases, the elimination pathways remained undiscovered; however, sorption processes seem to have a negligible impact.

A new method for the analysis of sulfonamides and tetracyclines in heterogenic biogas plant input samples and fermentation residues is introduced. Veterinary antibiotics are only partially absorbed in the animal gut; therefore, animal manure can contain high loads of these substances. Animal manure is used for biogas generation, so antibiotics can enter the anaerobic fermentation process this way. However, only little is known about the fate of antibiotics within this process, also due to the lack of suitable analytical methods for this complex sample matrix. Therefore, we developed a method for the analysis of ten sulfonamides (sulfachloropyridazine, sulfadiazine, sulfadimethoxine, sulfaguanidine, sulfamerazine, sulfamethazine, sulfamethoxazol, sulfamethoxypyridazin, sulfapyridine, sulfathiazole) and four tetracyclines (chlortetracycline, doxycycline, oxytetracycline, tetracycline) in biogas plant input and output samples, including a single liquid-liquid-extraction step and analysis via liquid chromatography (LC) and triple quadrupole mass spectrometry. The detection limit of this method ranges from 0.01 to 0.08 mg kg(-1). Matrix calibration using antibiotic-free cattle feces and isotopic-labeled internal standards enables quantification of antibiotics in different matrices such as animal manure, dung, or fermenter outputs with recovery rates between 70 and 130 %. This makes the method suitable for investigating the fate of antibiotics in animal manure and fermentation processes. A screening of 15 German biogas plants revealed the presence of several antibiotics up to 9 mg kg(-1) (201 mg kg(-1) dry matter). During the fermentation process, elimination occurs; however, with the exception of chlortetracycline, the antibiotic content remains in the same order of magnitude.

The sulfur metabolite dimethylsulfoniopropionate (DMSP) is the most important precursor of the climate relevant metabolite dimethylsulfide (DMS). It has thus gained interest in the context of climate change and several studies investigated the influence of elevated temperature and/or CO2 on DMSP in complex plankton communities. However, only little information about changes in response to these factors in single species is available. Therefore, we analyzed DMSP in different phytoplankton cultures (Thalassiosira pseudonana, Phaeodactylum tricornutum, Emiliania huxleyi) under the influence of increased temperature by 6 °C and elevated CO2 to 790 ppmv. In addition, we addressed glycine betaine (GBT) that fulfills a similar function as osmolyte like DMSP. In all cultures GBT concentrations increased at higher temperature and decreased at elevated CO2. In contrast, diatoms and prymnesiophytes revealed opposite trends for DMSP. In diatoms increased CO2 and temperature led to decreased DMSP concentrations, while rather elevated levels of this metabolite under the influence of these parameters were observed for E. huxleyi.

No change here: Analysis with doubly labeled [(13)C(2)D(6)]DMSP and LC/MS revealed that dissolved DMSP is taken up and stored intracellularly by diverse phytoplankton species without transformation. This is even true for species that produce no quantifiable amounts of DMSP themselves.

s / Toxicology Letters 229S (2014) S40–S252 S131 a quarter of that dose were tested. This analyzes showed no dose dependence of the test organism to the product. Statistical analysis of the micronucleus test showed that only the lowest dose tested causes chromosome instability on the organism tested, caused by genotoxic effect, indicating possible residual effects of this pesticide. http://dx.doi.org/10.1016/j.toxlet.2014.06.465