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Toxin Composition (toxin + composition)

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Life Sciences	50%

Selected Abstracts

Variation in toxin compositions of two harmful raphidophytes, Chattonella antiqua and Chattonella marina, at different salinities

ENVIRONMENTAL TOXICOLOGY, Issue 2 2002
Shahroz Mahean Haque
Abstract Toxin compositions of the two species of raphidophytes, Chattonella antiqua (Hada) Ono and Chattonella marina (Subrahmanyan) Hara et Chihara, were investigated at different salinities under laboratory conditions. C. antiqua contained toxin components CaTx-I, CaTx-II, CaTx-III, and CaTx-IV, which corresponded to brevetoxin components PbTx-1, PbTx-2, PbTx-3, and oxidized PbTx-2. Similarly, C. marina included CmTx-I, CmTx-II, CmTx-III, and CmTx-IV corresponding to PbTx-2, PbTx-9, PbTx-3, and oxidized PbTx-2. Toxin yields in both species varied markedly with a change in salinity concentration. In C. antiqua CaTx-I, CaTx-II, and CaTx-III peaked at 25 P.P.t. with yields of 0.99, 0.42, and 2.90 pg/cell, but the highest yield (2.35 pg/cell) of CaTx-IV was attained at 30 P.P.t. The yields of all CaTx components decreased sharply at salinities exceeding 30 P.P.t. On the other hand, C. marina yielded higher proportions of CmTx-I (0.55 pg/cell) and CmTx-III (2.50 pg/cell) at 25 P.P.t. However, CmTx-IV was present in its highest amount (1.65 pg/cell) at 30 P.P.t., as seen in C. antiqua. A small amount of CmTx-II was also detected at 20 P.P.t.,35 P.P.t. Both species showed the highest ichthyotoxicities at 25 P.P.t., at which the maximum cell division rate was obtained. © 2002 Wiley Periodicals, Inc. Environ Toxicol 17: 113,118, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/tox.10039 [source]

PRODUCTION OF PARALYTIC SHELLFISH TOXINS BY APHANIZOMENON SP.

JOURNAL OF PHYCOLOGY, Issue 4 2002
LMECYA 31 (CYANOBACTERIA)
We examined intracellular and extracellular paralytic shellfish toxins (PST) in a strain of Aphanizomenon sp. (LMECYA31) isolated from a Portuguese freshwater reservoir throughout the growth cycle and under different conditions affected by temperature and nitrate and phosphate availability. PST concentrations and compositions were greatly influenced by cell density, growth stage, and temperature and nutrients conditions. On a per-cell basis results showed (1) the enhancement of PST cell quota after the end of exponential growth phase in nutrient replete batch cultures, (2) the absence of a PST increment at late growth stages under phosphate limitation, (3) a rise in PST maximum cell quota under nitrate depletion, and (4) the enhancement of toxin production at higher temperatures. The relative proportion of the four toxins detected, neoSTX, dcSTX, STX and GTX5, also changed within and between culture settings. While growing under phosphate rich media cells produced mainly GTX5 and neoSTX, whereas under phosphate limitation the proportion of STX and dcSTX increased substantially with culture age. Large amounts of extracellular toxins were found in the culture medium, increasing during culture time. Extracellular toxin composition in each culture was fairly constant and always similar to the intracellular composition found at late stages of growth. This further supported other research that indicates that PSTs are released to the water through cell lysis, and a significant concentration of PST may be expected to remain in the water upon the collapse of a toxic bloom or after cells removal by water treatment. [source]

Geographic differences in paralytic shellfish poisoning toxin profiles among Japanese populations of Alexandrium tamarense and A. catenella (Dinophyceae)

PHYCOLOGICAL RESEARCH, Issue 1 2001
Takashi Yoshida
SUMMARY To reconsider whether toxin profile could be used as a marker for populations from different geographical areas, clonal isolates of the toxic dinoflagellates Alexandrium tamarense (Lebour) Balech and Alexandrium catenella (Whedon et Kofoid) Balech from Ofunato Bay (Iwate Prefecture), Atsumi Bay (Aichi Prefecture), Tanabe Bay (Wakayama Prefecture), Harima-Nada (Kagawa Prefecture), Uranouchi Bay (Kochi Prefecture), Hiroshima Bay (Hiroshima Prefecture) and Yamakawa Bay (Kagoshima Prefecture), which were identified on the basis of morphotaxonomy, immunological and molecular biological techniques, were subjected to analysis of paralytic shellfish poisoning toxins by high performance liquid chromatography-fluorometric method. All the isolates except A. tamarense OF152 from Ofunato Bay contained mainly N-sulfocarbamoyl toxins (C1 +2) with various amounts of derivatives, and a typical north-to-south trend of decreasing toxicity was observed. In both A. tamarense and A. catenella, toxin profiles were rather constant within a geographical area and divergent among different geographical areas. The toxin profiles of A. tamarense from Harima-Nada were well conserved among different bloom years. Toxin profile showed that isolates of A. tamarense from Ofunato Bay, A. tamarense from Harima-Nada isolated in 1988 and A. catenella from Uranouchi Bay were heterogeneous. However, only two or three groups of isolates with different toxin profiles were observed in a geographical region, suggesting that several representative isolates express the genotype in a given region. These observations confirmed that toxin composition could be used as a marker to discriminate different geographical populations of these species. [source]