• Korean Journal of Fisheries and Aquatic Sciences
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• v.25 no.2
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• pp.144-150
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• 1992

Paralytic shellfish toxins in mussels Mytilus edulis and dinoflagellate Alexandrium tamarene from Jinhae Bay, south coast of Korea were investigated. The mussels collected in March-April, 1989 showed toxicities of 7.5 MU/g of whole meat(31-88 MU/g of the digestive gland) , and those collected in 1990 showed toxicity level of 1.9-9.9 MU/g of whole meat by the standard mouse bioassay. Analysis of toxins by high performance liquid chromatography revealed the presence of gonyautoxin 1-4$(48-76\%)$ gonyautoxin 8 and epi-gonyautoxin $8(C1-C2,\;14-39\%)$, saxitoxin$(1-10\%)$, neosaxitoxin$(l-7\%)$ and trace amount of decarbamoylgonyautoxin 2 and 3(dcGTX2, dcGTX3) in the mussels of 1989. While, Mussels collected in 1990 contained a significantly larger proportion of neosaxitoxin $(44-50\%)$ than did those of 1989. A. tamarense isolated in April 1989 produced the same toxins in culture with slightly higher proportion of Cl, C2, dcGTX2 and dcGTX3 than in the mussels. The difference was within a range of toxin change during accumulation by shellfish and during sample preparation for analysis. It was thus concluded that the dinoflagellate was the cause of toxins in the mussels.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.20 no.4
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• pp.293-299
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• 1987

At various times and places all over the world men have become ill and some have died after eating shellfish that were intoxicated with paralytic shellfish poison(PSP) caused by Protogonyaulax spp. In late March, 1986, two persons were dead by ingesting wild sea mussels, Mytilur edulis, grown at bottom of an anchored waste ship to be dismantled at Gamchun Bay, Pusan, Korea. The samples were collected from the bottom of the ship during April $1\~April$ 8 of the year to find the cause of the food poisoning accident. The toxicity was estimated by bioassay with ICR male mouse, while the toxins were extracted and characterized. The toxins were extracted with acidified $80\%$ ethanol. The extract was defatted three times with dichloromethane, treated with activated charcoal, and then purified by chromatography on Bio-Gel P-2 and Bio-Rex 70. The toxic fractions obtained were analysed by cellulose acetate membrane electrophoresis, thin layer chromatography and high performance liquid chromatogaphy. The range and the average of PSP-toxicity of the samples were $132\~295\;MU/g$, 203 MU/g respectively. The amount of PSP was $26.4\~58.9{\mu}g/g$ of whole meat in range and $40.6{\mu}g/g$ in average. The toxicity of the digestive gland of the samples was 9 times higher than that of edible meat (except digestive gland) as $439\~979MU/g$, and it was about $70\%$ in total toxin. The compositional analytical results of the paralytic shellfish toxin, Gonyautoxin $1\~4$ were the major part of the PSP and Saxitoxin and neosaxitoxin were detected as the minor component. It was concluded that the food poisoning accident was caused not by Saxitoxins but by Gonyautoxins.

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.2
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• pp.212-218
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• 2006

Changes of paralytic shellfish poison (PSP) contents, toxicity and toxin composition with pH and storing periods at different temperature in toxic blue mussel, Mytilus edulis, were tested by using fluorometric HPLC method. Toxicity at pH 3 was the highest as 14.1 MU/g $(100\%)$ and showed 12.9 MU/g $(92.1\%)$ at pH 5, 9.0 MU/g $(63.8\%)$ at pH 7, 3.6 MU/g $(25.5\%)$ at pH 9 and 0.8 MU/g $(5.7\%)$ at pH 10 which suggested PSP was unstable at alkaline conditions. The decrease in toxicity during storage days was depend on pH and temperature. The toxicity markedly decreased until during the first S day storage $(19.9\~65.3\%)$ at all pH (3, 5, 7, 9) and temperature (30, 5, $-20^{\circ}C$), but, slightly decreased after then till to 30 days. C group toxin (C1 and C2) was the major components and other toxins such as GTX 1,2,3,4, STX and dcSTX were detected. Among the 8 toxins, GTX1,4, dcSTX and STX were firstly decreased according to the decreasing the toxicity at all processing conditions. The toxicity in blue mussel (14.1 MU/g) were able to remove by heating over 10 minutes at pH higher than 7.

• Journal of Food Hygiene and Safety
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• v.32 no.6
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• pp.542-549
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• 2017

To evaluate bacteriological and toxicological safety, the hygienic indicator bacterium and paralytic and diarrhetic shellfish toxins in the shellfish produced in the Kamakman Area from 2012 to 2016 were investigated. Fecal coliforms and E. coli of all 194 oyster samples tested did not exceed 230 MPN/100 g. The geometric mean of the fecal coliform analyzed with the oyster samples of harvesting period was 19.6 MPN/100 g, which was more stable than the non-harvesting period (26.5 MPN/100 g). For the toxicological evaluation of the Kamakman Area, 77 oyster samples and 350 mussel samples as an indicator were analyzed. Paralytic shellfish toxins were detected very low in the range of $40{\sim}46{\mu}g$/100 g in 13 mussel samples during late April and early June, but not in oyster samples. Diarrhetic shellfish toxin was detected in 2 of 180 samples, but it was found to be below the regulation value (0.16 mg OA equ./kg). Based on the bacteriological studies, it was confirmed that the shellfish produced in Kamakman area meets the standard of shellfish hygiene of the Food Sanitation Act and meets the Grade A of the shellfish production area of EU. As the results of the paralytic and diarrhetic shellfish toxin evaluation, it was confirmed that the Kamakman Area is also toxicologically safe for shellfish production.

• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.6
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• pp.924-928
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• 2005

Toxin profiles of the paralytic shellfish poison (PSP) detected from domestic shellfishes collected at the market and imported. shellfishes were invested by fluorometric HPLC. Total 9 components in PSP were analysed from the imported ark shell, such as saxitoxin (STX), decarbamoylsaxitoxin (dcSTX), gonyautoxin (GTX) - 1,2,3,4,5, Cl and C2. Among those toxins, 7 components except for GTX1,4 were detected from domestic shellfishes and showed different toxin contents and toxin compositions by species. Only C group toxin (Cl +2) contained in short necked clam and hard clam $(0.06\~0.56\;nmole/g)$ which living under soil but, in the blue mussels and oysters which cultured in the open sea water, showed more higher toxicity and complicate toxin compositions. Toxin compositions in bloody clam and purplish washington clam were very different in some samples even in same species. GTX4 and GTX5 were higher in imported scallop and STX was higher in imported ark shell than other species.

• Journal of Food Hygiene and Safety
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• v.35 no.6
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• pp.521-534
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• 2020

Paralytic shellfish poisoning (PSP) occurs when saxitoxin (STX), which is produced by harmful algae (dinoflagellates) and then accumulated in bivalve shellfish by filter-feeding, is consumed by humans. With recent advances in analysis technology, it has been reported that dinoflagellates also produce a variety of analogues such as the gonyautoxin (GTX) group and the N-sulfo-carbamoyl toxin (C toxin) group, in addition to STX. Accordingly, CODEX and the EFSA are stepping forward to manage STX and analogues as STX groups requiring safety management. In Korea, the occurrence of dinoflagellates producing STX analogues has already been reported, and contamination of analogues (GTX group, C toxin group) in live mussels has also been reported. In this study, in order to provide the basis for systematic monitoring and safety management of STX and analogues, their physicochemical characteristics, occurrence of dinoflagellates, toxicity and toxic equivalency factor, analytical method and occurrence were widely reviewed. This review is expected to contribute to strengthening the safety management of STX and its analogues.

• Fisheries and Aquatic Sciences
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• v.7 no.4
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• pp.175-183
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• 2004

The dinoflagellate Alexandrium tamiyavanichii Balech, a producer of toxins causing paralytic shellfish poisoning (PSP), has recently been considered as one of main organisms responsible for toxication of shellfish in Japan. In this study, A. tamiyavanichii was subjected to a molecular phylogenetic analysis inferred from 28S rDNA D1-D2 sequences and a species-specific LSU rRNA-targeted oligonucleotide DNA probe was designed to identify A. tamiyavanichii using the whole cell-FISH (fluorescence in situ hybridization). The sequences of the 28S rDNA D1-D2 region of A. tamiyavanichii showed no difference from A. cohorticular AF1746l4 (present name A. tamiyavanichii) and formed a distinct clade from the 'tamarensis species complex'. The probe, TAMID2, reacted specifically with A. tamiyavanichii cultured cells, without any cross-reaction with other species belonging to the same genus, including A. tamarense, A. catenella, A. affine, A. fraterculus, A. insuetum and A. pseudogonyaulax. In a test of cross-reactivity with a field sample, TAMID2 reacted consistently with only A. tamiyavanichii, indicating that the present protocol involving the TAMID2 probe might be useful for detecting toxic A. tamiyavanichii in a simple and rapid manner.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.29 no.2
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• pp.165-173
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• 1996

Large amounts (300 grams) of natural red tide plankton, Cochlodinium polykrikoides, was collected at the Yokji island coastal waters, Kyeongnam, Korea, on October, 1993. Using the bioassay systems, bioactive materials were screened from methanol extracts of C. polykrikoides. Live C. polykrykoides was toxic to fishes, however, the water soluble and chloroform soluble fraction of their methanol extracts did not shown ichthyotoxicity (5 mg/ml), and toxicity to mice (50 mg, i.p,). These fractions did not show any peaks corresponding to paralytic shellfish toxins or diarryhetic shellfish toxins on the fluorometric HPIC chromatograms. Neither fractions did not show antibiotic activities by paper disk (10 mg/disc) test and chloroform soluble fraction showed only $20\%$ growth inhibition activity on the Lymphoid P-388 at the concentration of $180\;{\mu}g/ml$. Hemolytic activity was detected by both fractions. Fatty acid analysis by GC, GC/MS and proton NMR showed that the chloroform soluble fraction composed of $25.3\%$ of DHA (dorosahexaenoic acid) and $15.3\%$ of IPA (eicosapentaenoic acid) as the hemolytic components.

• Journal of the Korean Society of Marine Environment & Safety
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• v.28 no.6
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• pp.866-873
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• 2022

Growth rate and production of the paralytic shellfish poisoning toxin (PST) of a toxic dinoflagellate Alexandrium pacificum (LIMS-PS-2611) isolated from the southern sea of Korea, were examined under various temperatures and salinity conditions. The maximum growth rate (0.28 day^-1) was observed under 25℃ and 30 psu. Optimal growth (≥ 70% of maximum growth rate) was obtained between 20~25℃ and 25~35 psu. Among the PSTs of A. pacificum, the principal toxins were C1+2 and GTX5 in N-sulfocarbamoyl toxin group, and minor components were characterized as neoSTXs in the carbamate toxin group. Maximum toxin content was observed under 20℃ and 30 psu, and the toxin content increased with the increase of salinity. Low toxin contents were measured under the temperature and salinity conditions of the maximum growth rate. Therefore, the PSP of bivalve, which occurs at a temperature range of 20-25℃ in June, might have been derived from A. pacificum.

• Journal of Food Hygiene and Safety
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• v.13 no.2
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• pp.143-148
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• 1998

The purpose of this study was to determine the kinetics of paralytic shellfish poison (PSP) destruction at various temperature. The toxic digestive gland homogenate of blue mussel (Mytilus edulis), PSP crude toxin, gonyautoxin group and saxitoxin group were heated at temperature ranging from 90 to $120^{\circ}C$, and then the toxicities were measured in samples heated for various time intervals. The rate constant (k) of the toxic digestive gland homogenate, PSP crude toxin, gonyautoxin group and saxitoxin group were $3.28{\times}10^{-2},\;1.20{\times}10^{-2},\;5.88{\times}10^{-2}\;and\;2.58{\times}10^{-2}\;at\;120^{\circ}C$, respectively. The decimal reduction time (D-value) of the toxic digestive gland homogenate, PSP crude toxin, gonyautoxin group and saxitoxin group were 70, 192, 39 and 89 at $120^{\circ}C$, respectively. These results indicate that PSP crude toxin is most heat-stable of 4 types of PSP toxins and PSP toxin are more heat-stable than food poisoning bacteria and spores. The retorting condition to reduce PSP toxicity below quarantine limit ($80\;\mu\textrm{g}/100\;g$ in Korea and America, 4 MU/g in Japan) could be calculated by rate constant. For example, the digestive gland homogenate having a initial toxicity of $200\;\mu\textrm{g}/100\;g$ could have toxicity below quarantine limit when heated at $90^{\circ}C$ for 129 min., $100^{\circ}C$ for 82 min., $110^{\circ}C$ for 48 min. and $120^{\circ}C$ for 28 min. These results suggest that commercial retorting condition ($115^{\circ}C$ for 70 min) in Korea is enough to reduce toxicity below quarantine limit from initial toxicity of $200\;\mu\textrm{g}/100\;g$. From these results, the quarantine limit of PSP-infested shellfish for canning can be level up to raw score of $200\;\mu\textrm{g}/100\;g$.