Paralytic Shellfish Toxin Production Research Articles

Evidence for production of paralytic shellfish toxins by bacteria associated with Alexandrium spp. (Dinophyta) in culture

A substantial proportion of bacteria from five Alexandrium cultures originally isolated from various countries produced sodium channel blocking (SCB) toxins, as ascertained by mouse neuroblastoma assay. The quantities of SCB toxins produced by bacteria and dinoflagellates were noted, and the limitations in comparing the toxicities of these two organisms are discussed. The chemical nature of the SCB toxins in selected bacterial isolates was determined as paralytic shellfish toxins by pre- and postcolumn high-performance liquid chromatography, capillary electrophoresis-mass spectrometry, and enzyme immunoassay.

Vertical migration, nutrition and toxicity in the dinoflagellate Alexandrium tamarense

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 148:201-216 (1997) - doi:10.3354/meps148201 Vertical migration, nutrition and toxicity in the dinoflagellate Alexandrium tamarense MacIntyre JG, Cullen JJ, Cembella AD The effect of nitrate-N availability on paralytic shellfish toxin production by the dinoflagellate Alexandrium tamarense was studied in a vertically stratified laboratory water column (tank) where swimming behavior could influence photosynthesis and nutrition. Results were compared with those from batch and semi-continuous cultures in which migratory behavior was not a factor. The batch and semi-continuous cultures demonstrated a direct positive relationship between N availability and toxin content. Steady-state cultures, maintained at 2 contrasting rates of semi-continuous N supply, also demonstrated significantly different cellular toxin profiles (relative proportion of toxins). The tank experiment was carried out in a 2.1 m PVC cylinder (0.29 m internal diameter) and lasted for 24 d. Initially, nitrate was replete throughout the water column (50 µM) and the highly toxic cells formed a thin surface layer which persisted throughout the 14 h light:10 h dark cycle. When nitrate was depleted in the surface layer as a result of uptake by the phytoplankton, the cells began a nocturnal migration to the nitracline. During this phase the toxin content of the cells decreased gradually as the C:N of the cells increased. In the third phase, the deep nitrate pool was exhausted and the cells penetrated deeper during the dark period. The toxin content of the cells reached the lowest level during this phase. When nitrate was added to the deep layer, a fourth phase began, during which nocturnal descent of the migrating cells was again restricted to the nitracline; toxicity of the cells increased and C:N declined. Finally, N was added to the surface layer. During this fifth and final phase, cellular toxicity continued to rise, C:N declined further, and the cells continued to migrate to the thermocline during the dark period. The toxicity of the cells during the N-stratified phases of the water column experiment was intermediate between the N-replete and N-depleted phases, indicating that A. tamarense is capable of producing PSP toxins from N acquired during a nocturnal descent. It is concluded that toxic dinoflagellates inhabiting N-depleted coastal waters are likely capable of sustaining growth and a moderate level of toxicity through nocturnal migrations to deep N pools. Alexandrium tamarense · PSP · Vertical migration · Nitrogen · Dinoflagellate · Toxin profile · N-stratified · Red-tide Full text in pdf format PreviousNextExport citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 148. Publication date: February 27, 1997 Print ISSN:0171-8630; Online ISSN:1616-1599 Copyright © 1997 Inter-Research.

Production of paralytic shellfish toxins by a bacterium Moraxella sp. isolated from Protogonyaulax tamarensis

A bacterium Moraxella sp. isolated from Protogonyaulax tamarensis was cultured in various conditions. Changes of toxicity and toxin components of the cells during culture were analyzed by bioassay and HPLC-fluorometric analysis. Toxin productivity of Moraxella sp. increased when it was cultured in nutrition-deficient environments. The main toxins produced by Moraxella sp. in these conditions were gonyautoxins (GTXs), mainly GTX 1 and 4 which are major toxins of P. tamarensis.

Use of high-performance liquid chromatography to investigate the production of paralytic shellfish toxins by Protogonyaulax spp. in culture

Procedures have been developed for the extraction and high-performance liquid chromatography (HPLC) analysis of paralytic shellfish poisoning (PSP) toxins from Protogonyaulax spp. grown in batch culture. Using these procedures, the toxin content of two isolates of P. tamarensis (NEPCC 183 and 255) and one isolate of P. catenella (NEPCC 355) were examined. Total toxin and individual toxin concentrations were measured for each isolate during the exponential and stationary phases of growth in batch culture. The total toxicity of each isolate as measured by HPLC analysis was found to agree with toxicity as determined by the standard mouse bioassay. Two of the isolates (255 and 355) were found to be toxic and the third (183) was non-toxic. The toxic isolates (255 and 355) both showed higher average total PSP toxin content during the exponential phase (35 and 23 fmol toxin cell-1, respectively) than during the stationary phase (21 and 8 fmol toxin cell-1, respectively). These cultures differed dramatically in their toxin composition. P. tamarensis (255) contained a large proportion of the N(21) sulfo toxins (B1, B2, C1, C2) while P. catenella (355) contained primarily Gonyautoxins 1 through 4. The percent composition of individual toxins was found to be constant throughout the growth cycle for both toxic isolates, even though the total toxin concentration varied. Our results suggest that PSP toxin profiles might be useful as chemotaxonomic indicators.