Application of a screening method for cyanobacterial toxins in natural samples

Cyanobacterial toxins as microcystins (MCs), nodularins (NODs), Paralytic Shellfish Poisoning (PSP) toxins, anatoxins (ANAs), and cylindrospermopsins (CYNs) with over 100 known varieties, occur worldwide associated with human and animal lethal poisoning.In contrast to all analytical methods for toxin determination are based on LC/MS-MS measurements with Multiple Reaction Monitoring (MRM) the application of Precursor Ion mode allows the coverage of all these structural variants. Although in MRM mode enables a higher sensitivity, a lot of information regarding structural changes is missed. The new generation of Q-TRAPs combines the advantages of quadrupoles having a high selectivity with the high sensitivity of ion-trap systems. Here we published results, showing the suitability of Precursor Ion mode for detection of cyanobacterial toxins extracted from phytoplankton

Effects of salinity, temperature and nutrients on growth, cellular characteristics and yessotoxin production of Protoceratium reticulatum

Protoceratium reticulatum as a producer of yessotoxin (YTX) and its analogues is common in several coastal environments. The YTX-producing strain of P. reticulatum, isolated from the German Bight (North Sea), was analysed to study toxin production under various autecological conditions. Experiments were carried out to investigate the influence of N/P ratio (2.44 (1/10 N), 24.36 (f/2) and 243.65 (1/10 P)), temperature (15 and 20 °C), salinity (5, 10, 15, 20, 25 and 30) and growth phase on YTX formation, cell size and chlorophyll a concentration. P. reticulatum showed the highest growth at 15 °C and higher salinities (25 and 30). In particular, higher temperature led to a reduced growth. The total YTX concentrations were higher at lower temperature. However, a clear correlation between salinity and YTX production was not observed at lower temperature. Furthermore, 1/10 P and f/2 cultures exhibited the highest cell quota of YTX at the end of the stationary phase; a dramatic effect occurred at 15 °C in 1/10 P media, when the toxicity increased to ten fold higher values. Slight variations of the composition of the YTX analogues under nutrient limitation were observable. In addition, the results indicate that N-limitation cause a lower cell size, whereas P-limitation leads to a higher cell size; an influence of the salinity on cell size was also observable

Analysis of Marine Biotoxins using LC-MS/MS

Different clinical types of algae-related poisoning have attracted scientific and commercial attention: paralytic shellfish poisoning (PSP), diarrhetic shellfish poisoning (DSP), and amnesic shellfish poisoning (ASP). Bioassays are common methods for the determination of marine biotoxins. However, biological tests are not completely satisfactory, mainly due to the low sensitivity and the absence of specialized variations. Therefore, many efforts have been made to determine algal toxins using different chemical methods. In this context LC-MS methods replaced HPLC methods with optical detectors, allowing both effective seafood control and monitoring of phytoplankton in terms of the different groups of marine biotoxins. This chapter describes state-of-the-art LC-MS/MS methods for the detection and quantitation of different classes of phycotoxins in shellfish matrices. These classes include the highly hydrophilic paralytic shellfish poisoning (PSP) toxins. , which have been traditionally separated by ion pair chromatography followed by derivatization and fluorescence detection. However, the ion pair reagents added to the mobile phases are not compatible with mass spectrometry, so a new chromatographic system had to be developed. Hydrophilic interaction liquid chromatography (HILIC) has been shown to be useful in the separation of PSP toxins and is described in detail within this chapter. Another important class of phycotoxins are diarrhetic shellfish poising (DSP) toxins. This group traditionally comprises okadaic acid and dinophysistoxins (DTXs), pectenotoxins (PTXs) and yessotoxins (YTXs). The latter two groups are often associated with diarrhoea causing DTXs, but recently turned out not to have diarrhetic effects by themselves, which means in the strict sense they are no DSP toxins. For this reason the term “lipophilic” toxins rather than DSP is increasingly applied to for this group of toxins. The most recently described shellfish poisoning syndrome, azaspiracid shellfish poising (AZP) is caused by azaspiracids, which in turn are diarrhetic, but usually are treated separately as AZP. The last group of regulated shellfish toxins is the amnesic shellfish poisoning (ASP) toxin domoic acid, produced by species of the genus Pseudo-nitzschia

Roboterzelle zur Feinbearbeitung großer Werkzeuge* Prozessentwicklung zum roboterbasierten Polieren und Schleifen von Spritzgießwerkzeugen

Die manuelle Feinbearbeitung als letzter Prozessschritt der Spritzgießwerkzeugherstellung ist für die Produktqualität entscheidend. Da Qualität und Zeitaufwand wesentlich vom individuellen Geschick des Handwerkers abhängen, führen die hohen Lohnkosten und fehlende Fachkräfte zu einem signifikanten Wettbewerbsnachteil für den Werkzeug- und Formenbau in Deutschland. Um zukünftig den manuellen durch einen automatisierten Feinbearbeitungsprozess zu ersetzen, ist die Entwicklung eines robusten, industrietauglichen Robotersystems von essentieller Bedeutung. Robot cell for the finishing of large tools and dies - Process development for robot-based polishing and grinding of injection moulds Manual finishing as final process step in making tools is crucial for product quality. Today, the quality and the cost of tools depend very much on the individual skills of the experts. Due to high labor cost and a lack of skilled workers, the strong dependence on craftsmanship is a significant competitive disadvantage for tool making in Germany. To establish an automated finishing process on the market by replacing manual finishing, it is essential to develop a robust, industry-compatible, robotic syste

Roboterzelle zur Feinbearbeitung großer Werkzeuge* Prozessentwicklung zum roboterbasierten Polieren und Schleifen von Spritzgießwerkzeugen

Die manuelle Feinbearbeitung als letzter Prozessschritt der Spritzgießwerkzeugherstellung ist für die Produktqualität entscheidend. Da Qualität und Zeitaufwand wesentlich vom individuellen Geschick des Handwerkers abhängen, führen die hohen Lohnkosten und fehlende Fachkräfte zu einem signifikanten Wettbewerbsnachteil für den Werkzeug- und Formenbau in Deutschland. Um zukünftig den manuellen durch einen automatisierten Feinbearbeitungsprozess zu ersetzen, ist die Entwicklung eines robusten, industrietauglichen Robotersystems von essentieller Bedeutung. Robot cell for the finishing of large tools and dies - Process development for robot-based polishing and grinding of injection moulds Manual finishing as final process step in making tools is crucial for product quality. Today, the quality and the cost of tools depend very much on the individual skills of the experts. Due to high labor cost and a lack of skilled workers, the strong dependence on craftsmanship is a significant competitive disadvantage for tool making in Germany. To establish an automated finishing process on the market by replacing manual finishing, it is essential to develop a robust, industry-compatible, robotic syste

More and more toxins around-analysis of cyanobacterial strains isolated from Lake Chao (Anhui Province, China)

International audienceLake Chao, China, is highly eutrophicated and experiences recurrent dense cyanobacterial blooms. Its surface water is used as drinking water resource for Hefei city, hence the potential toxicity of those cyanobacteria was of interest. Sixteen isolated strains of Microcystis aeruginosa evidenced that non-toxic, toxic and highly toxic strains coexist in the lake. Microcystin variants within one strain ranged up to 11, the concentration up to 4.799 mg g DW1. Mass spectrometry analysis confirmed desmethylated microcystin variants