Thalassiosira weissflogii

Interestingly, okadaic acid diol ester (16) in the culture medium is oxidatively transformed into the more hydrophilic metabolites 18-20 by intact cells of the diatom Thalassiosira weissflogii [52,53]. This transformation is speculated to change the toxic metabolite with allelopathic activity into a less toxic transport form that can be better excreted by the diatom. 

Scheme 5 Release of okadaic acid (17) from less toxic precursors by E. lima (left). Oxidative transformation of okadaic acid diol ester (16) by the diatom Thalassiosira weissflogii (right)...

Fig 3 Images of phytoplankton cells from the Ebro river obtained by means of epifluorescence microscopy and scanning electron microscopy. Images correspond to the species Pediastrum duplex (a), Aulacoseira granulata (b), Stephanodiscus cf. neoastraea (c), Cyclotella meneghini-nana (d), Skeletonema potamos (e), and Thalassiosira weissflogii (f)... 

Pb complexes in the coastal diatom, Thalassiosira weissflogii, Environ. Sci. Tech-nol, 28, 1781-1790. 

Rich, H. W. and Morel, F. M. M. (1990). Availability of well-defined iron colloids to the marine diatom Thalassiosira weissflogii, Limnol. Oceanogr., 35, 652-662. 

Thalassiosira weissflogii Fe 3 x 10-3 0.9 - 3 x 10 3 Pulse-chase experiment and calculation based upon ka [192,290]... 

Thalassiosira weissflogii Fe > 1 x 10-4 Calculation based upon cellular requirement0 [7]... 

Cowie, G.L., and J.I. Hedges. 1996. Digestion and alteration of the biochemical constituents of a diatom (Thalassiosira weissflogii) ingested by an herbivorous zooplankton (Calanus pacificus). Limnology and Oceanography 41 581-594. 

Roberts et al. reported a 27 kDa monomeric carbonic anhydrase, TWCAl, from the marine diatom Thalassiosira weissflogii (221). X-ray absorption spectroscopy indicated that the catalytic zinc is coordinated by three histidines and a water molecule, similar to the active sites of the a- and y-CAs (222). Also, the active site geometry is similar to that of a-CAs. Based on these results the catalytic mechanism is expected to be similar to that of the -class carbonic anhydrases. Tripp et al. (223) proposed that this TWCAl is the prototype of a fourth class carbonic anhydrase designated as 8-class CAs. In the... 

Additionally, a number of marine toxins with medical and toxicological importance have been isolated from marine flora and fauna. Okadaic acid, Fig. (62) is the main toxin produced by dinoflagellates, which can accumulate in the hepatopancreas of mussels and caused diarrhetic shellfish poisoning in consumers [505,506], However, this toxin is also a tumor promoter and a specific potent inhibitor of protein phosphatases which may provokes mitotic arrest and apoptosis of leukemia cells [507-509], These types of compounds have been reported in shellfish and phytoplankton, and more recently, in Spanish mussels [510], Portuguese bivalves [511], and the diatom Thalassiosira weissflogii [512],... 

Anderson, M.A. and Morel, F.M.M., 1982. The influence of aqueous iron chemistry on the uptake of iron by the coastal diatom Thalassiosira weissflogii. Limnoi. Oceanogr., 27 789-813... 

Increased synthesis of MAAs by exposure to high intensity artificial visible light also occurs in the Antarctic diatom Thalassiosira weissflogii, the prasinophyte Pyramimonas parkae, and most markedly in the dinoflagellate Amphidinium carterae (six-fold increase over control).171 However, high visible light exposure does not affect the MAA content of two other unicellular algae, Dunaliella tertiolecta (Chlorophyta) and Isochrysis sp. (Haptophyta). Supplemental exposures with UVA and UVB in combination and alone result in a variety of species-specific responses. 

Phinney, J.T., and Bruland, K.W. (1994) Uptake of lipophilic organic Cu, Cd, and Pb complexes in the coastal diatom Thalassiosira weissflogii. Environ. Sci. Technol. 28, 1781-1790. 

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