Microbial utilization of the neurotoxin domoic acid: blue mussels (Mytilus edulis) and soft shell clams (Mya arenaria) as sources of the microorganisms

1998 ◽  
Vol 44 (5) ◽  
pp. 456-464 ◽  
Author(s):  
James E Stewart ◽  
L J Marks ◽  
M W Gilgan ◽  
E Pfeiffer ◽  
B M Zwicker
Keyword(s):  
Mytilus Edulis ◽  
Domoic Acid ◽  
Mya Arenaria ◽  
Resting Cells ◽  
Placopecten Magellanicus ◽  
Blue Mussels ◽  
Microbial Utilization ◽  
Soft Shell ◽  
Enrichment Techniques ◽  
Sea Scallops

The neurotoxin domoic acid is produced in quantity by the diatom Pseudo-nitzschia multiseries and is released to the environment directly and indirectly via food chains. Presumably there is a mechanism for the biodegradation and disposal of domoic acid and as bacteria are logical candidates for such an activity, a search for bacteria competent to carry out biodegradation of domoic acid was initiated. Extensive trials with a wide variety of bacteria isolated mainly from muds and waters taken from the marine environment showed that the ability to grow on or degrade domoic acid was rare; in fact, domoic acid was inhibitory to resting cells or growing cultures of most of these bacteria. In contrast, using enrichment techniques, it was possible to isolate from molluscan species that eliminate domoic acid readily, i.e., blue mussels (Mytilus edulis) and soft-shell clams (Mya arenaria), bacteria that exhibited growth with and biodegradation of domoic acid when supplemented with low concentrations of growth factors. The species that retain domoic acid for lengthy periods, such as sea scallops (Placopecten magellanicus) and red mussels(Modiolus modiolus), only occasionally yielded bacteria with this capability. The differences may be a result of the mechanisms used by the different shellfish in dealing with domoic acid, i.e., freely available in the blue mussels and soft shell clams but likely sequestered in the digestive glands of sea scallops and red mussels and thus, largely unavailable for bacterial utilization. The results show that Mytilus edulis and Mya arenaria, almost uniquely, are prime and reliable sources of domoic acid utilizing bacteria. These findings suggest a strong possibility that autochthonous bacteria may be significant factors in the elimination of the neurotoxin in these two species of shellfish.Key words: bacteria, neurotoxin, domoic acid, elimination, bivalve molluscs.

scholarly journals Extracellular Vesicles and Post-Translational Protein Deimination Signatures in Mollusca—The Blue Mussel (Mytilus edulis), Soft Shell Clam (Mya arenaria), Eastern Oyster (Crassostrea virginica) and Atlantic Jacknife Clam (Ensis leei)

Biology ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 416
Author(s):  
Timothy J. Bowden ◽  
Igor Kraev ◽  
Sigrun Lange
Keyword(s):  
Mytilus Edulis ◽  
Crassostrea Virginica ◽  
Blue Mussel ◽  
Binding Protein ◽  
Pdz Domain ◽  
Eastern Oyster ◽  
Mya Arenaria ◽  
Beta Catenin ◽  
Soft Shell Clam ◽  
Soft Shell

Oysters and clams are important for food security and of commercial value worldwide. They are affected by anthropogenic changes and opportunistic pathogens and can be indicators of changes in ocean environments. Therefore, studies into biomarker discovery are of considerable value. This study aimed at assessing extracellular vesicle (EV) signatures and post-translational protein deimination profiles of hemolymph from four commercially valuable Mollusca species, the blue mussel (Mytilus edulis), soft shell clam (Mya arenaria), Eastern oyster (Crassostrea virginica), and Atlantic jacknife clam (Ensis leei). EVs form part of cellular communication by transporting protein and genetic cargo and play roles in immunity and host–pathogen interactions. Protein deimination is a post-translational modification caused by peptidylarginine deiminases (PADs), and can facilitate protein moonlighting in health and disease. The current study identified hemolymph-EV profiles in the four Mollusca species, revealing some species differences. Deiminated protein candidates differed in hemolymph between the species, with some common targets between all four species (e.g., histone H3 and H4, actin, and GAPDH), while other hits were species-specific; in blue mussel these included heavy metal binding protein, heat shock proteins 60 and 90, 2-phospho-D-glycerate hydrolyase, GTP cyclohydrolase feedback regulatory protein, sodium/potassium-transporting ATPase, and fibrinogen domain containing protein. In soft shell clam specific deimination hits included dynein, MCM3-associated protein, and SCRN. In Eastern oyster specific deimination hits included muscle LIM protein, beta-1,3-glucan-binding protein, myosin heavy chain, thaumatin-like protein, vWFA domain-containing protein, BTB domain-containing protein, amylase, and beta-catenin. Deiminated proteins specific to Atlantic jackknife clam included nacre c1q domain-containing protein and PDZ domain-containing protein In addition, some proteins were common as deiminated targets between two or three of the Bivalvia species under study (e.g., EP protein, C1q domain containing protein, histone H2B, tubulin, elongation factor 1-alpha, dominin, extracellular superoxide dismutase). Protein interaction network analysis for the deiminated protein hits revealed major pathways relevant for immunity and metabolism, providing novel insights into post-translational regulation via deimination. The study contributes to EV characterization in diverse taxa and understanding of roles for PAD-mediated regulation of immune and metabolic pathways throughout phylogeny.

Gross Structure of the Adductor Muscles of Some Pelecypods

1973 ◽  
Vol 30 (10) ◽  
pp. 1583-1585 ◽  
Author(s):  
Carol M. Morrison ◽  
Paul H. Odense
Keyword(s):  
Mytilus Edulis ◽  
Crassostrea Virginica ◽  
Adductor Muscle ◽  
Mya Arenaria ◽  
Placopecten Magellanicus ◽  
Spisula Solidissima ◽  
Arctica Islandica ◽  
Modiolus Modiolus ◽  
Adductor Muscles ◽  
Clinocardium Ciliatum

A study of the gross structure of adductor muscles of the following pelecypods showed that they conform to Morton’s grouping into the a) "Protobranchia" (Nucula proxima and Yoldia limatula), b) "shallow-burrowing lamellibranchs" (Clinocardium ciliatum, Venericardia borealis, Astarte undata, Arctica islandica, Venus mercenaria, and Spisula solidissima), c) "surface attached lamellibranchs" (Mytilus edulis, Modiolus modiolus, Modiolus demissus, Placopecten magellanicus, and Crassostrea virginica), d) "deep-burrowing and immobile lamellibranchs" (Ensis directus, Hiatella arctica, and Mya arenaria); thus providing more evidence for his classification. The adductor muscle is divided into two portions — translucent and opaque — except in the "deep-burrowing and immobile lamellibranchs", which have opaque muscles only.

Accumulation of domoic acid by the sea scallop (Placopecten magellanicus) fed cultured cells of toxic Pseudo-nitzschia multiseries

1997 ◽  
Vol 54 (4) ◽  
pp. 907-913 ◽  
Author(s):  
D J Douglas ◽  
E R Kenchington ◽  
C J Bird ◽  
R Pocklington ◽  
B Bradford ◽  
...  
Keyword(s):  
Digestive Gland ◽  
Domoic Acid ◽  
Cultured Cells ◽  
Exposure Period ◽  
Adductor Muscle ◽  
Placopecten Magellanicus ◽  
Bivalve Molluscs ◽  
Destructive Sampling ◽  
Sea Scallop ◽  
Sea Scallops

Sea scallops (Placopecten magellanicus) were fed Pseudo-nitzschia multiseries (formerly P. pungens f. multiseries, Nitzschia pungens f. multiseries) cells of high domoic acid (DA) content (4.0-6.7 pg DA cdot cell-1) for 22 days, followed by 14 days of feeding with nontoxic microalgae. DA was incorporated within 24 h by the scallops, with increased uptake after 6 days, and was concentrated in tissues in the following order: digestive gland >> remaining soft tissue >> adductor muscle. A maximum DA concentration of 3108 mu g cdot g-1 was recorded in the digestive gland, approximately 150 times the regulatory limit (20 mu g DA cdot g-1) and among the highest levels observed in bivalve molluscs; however, only trace amounts, 0.7-1.5 mu g cdot g-1, were found concomitantly in the adductor muscle. At the end of the exposure period, 50.9% of the DA that had been supplied to the scallops had been incorporated into the tissues. Concentrations in the digestive gland 14 days after termination of the toxic diet remained high, 752 mu g DA cdot g-1. Throughout the experiment, there was no sign of illness or mortality attributable to high DA loading, although the destructive sampling of animals did not allow us to assess the effects of the toxin in the longer term.

Depuration of Domoic Acid from Live Blue Mussels (Mytilus edulis)

1992 ◽  
Vol 49 (2) ◽  
pp. 312-318 ◽  
Author(s):  
I. Novaczek ◽  
M. S. Madhyastha ◽  
R. F. Ablett ◽  
A. Donald ◽  
G. Johnson ◽  
...  
Keyword(s):  
Mytilus Edulis ◽  
Prince Edward Island ◽  
Domoic Acid ◽  
Unit Weight ◽  
Concentration Data ◽  
Blue Mussels ◽  
Significant Difference ◽  
Intracellular Compartments ◽  
Effects Of Temperature ◽  
Depuration Rate

Industrial depuration may provide a means of removing domoic acid toxin from blue mussels (Mytilus edulis). Mussels containing up to 50 μg domoic acid∙g−1 were transported from a Prince Edward Island estuary into controlled laboratory conditions to test the effects of temperature, salinity, mussel size, and feeding upon depuration. Fifty percent of toxin was eliminated within 24 h. After 72 h, mussels were either clean or contained, on average, only residual levels of toxin (< 5 μg∙g−1), regardless of conditions. Exponential depuration curves were fitted to the domoic acid concentration data. To evaluate differences in rate of depuration under various conditions, statistical comparisons were made between slopes of the clearance curves. Rates of depuration were faster in small (45–55 mm) than in large mussels (60–70 mm) and more rapid at 11 than at 6 °C. There was no significant difference in depuration rate at 18‰ salinity as opposed to 28‰ or in starved versus fed mussels. Because of their relatively large digestive glands, meats of small mussels contained more toxin per unit weight than meats of large mussels. The bulk of domoic acid appeared to reside in the gut lumen. However, the presence of small amounts of domoic acid in intracellular compartments cannot be ruled out.

Possible Effects of Passamaquoddy Power Project on Clams, Scallops and Shipworms in Canadian Waters

1962 ◽  
Vol 19 (5) ◽  
pp. 877-889
Author(s):  
J. C. Medcof
Keyword(s):  
Water Exchange ◽  
Mya Arenaria ◽  
Bay Of Fundy ◽  
Placopecten Magellanicus ◽  
Soft Shell Clam ◽  
Economic Significance ◽  
Breeding Populations ◽  
Soft Shell ◽  
Power Project ◽  
Reduced Water

Only three molluscs in the Passamaquoddy region of the Bay of Fundy have economic significance. The annual soft-shell clam (Mya arenaria) production now at 4 million lb will drop 2 million and fishermen's earnings will drop to $100,000 because the area of clam flats in the High Pool will decrease 95%. Annual scallop (Placopecten magellanicus) production, now at 60,000 lb, will increase to about 90,000 lb and fishermen's earnings will increase to about $36,000 because reduced water exchange in the High Pool will favour survival of larvae and recruitment of scallop stocks. The shipworm (Teredo navalis), no problem now, will become an expensive pest in the Low and High Pools because higher water temperatures will encourage the build-up of heavy breeding populations.

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