Diatoms pennate

Many diatoms, especially pennate diatoms, are attached to substrates for much of their lives. This presents a unique problem for the electron... 

Phytene is an example of a diterpene. It is found as the phytyl side chain in chlorophyll a and vitamin K. Haslene is an example of a sesterpene. It is an imsaturated and branched simple lipid synthesized by marine pennate diatoms. One of the largest femilies of terpenes... 

The term amnesic shellfish poison (ASP) has been coined for this new shellfish toxin. The causative organism of ASP was then identified to be the pennate diatom Nitzschia pungens Grunow f. multiseries Hasle, a bloom of which contaminated the cultured mussels in eastern Prince Edward Island in 1987. 

Bacillariophvceae (centric and pennate diatoms . For the most part, the diatoms are not significant producers of DMS. An exception is the estuarine species, Melosira nummuloides. In sufficient numbers (i.e. bloom situations) certain other species could be important. Therefore diatoms cannot be summarily dismissed as sources of DMS some consideration of species composition must be included. 

The colonization of two Phaeocystis species (Prymnesiophyceae) by pennate diatoms and other protists a significant contribution to colony biomass... 

The coexistence of Phaeocystis species with pennate diatoms and other protists, although not universally observed, is a well-known and common phenomenon (Hasle 1964 Rousseau et al. 1994 Hasle and Syvertsen 1997 Peperzak etal. 1998 Wassmann et al. 1999 Throndsen et al. 2003 Hamm and Rousseau 2003). In general, the colonization of... 

Lewin J, Hellebust JA (1976) Heterotrophic nutrition of the marine pennate diatom Nitzschia angularis var. aff-inis. Mar Biol 36(4) 313-320... 

In 1987, the first confirmed case of a naturally occurring neurotoxic diatom bloom was reported in Prince Edward Island, Canada, later confirmed to be caused by the production of domoic acid from the pennate diatom Nitzschia pungens, now renamed Pseudo-nitzschia multiseries (Bates et ah, 1989 Subba Rao et ah, 1988). Since this first outbreak, many (but not aU) species of Pseudo-nitzschia have been confirmed to produce domoic acid (as well as some species of Amphora and now Nitzschia (Kotaki et ah, 2000) see Bates, 1998, 2000, for a summary). These potentially toxic species include P. multiseries, P. pseudodelicatissima, P. delicatissima, P. seratia, P. australis, P. pungens, and P.fraudulenta, although it is apparent that not aU species are toxic in aU locations, nor are individual strains toxic under aU conditions. 

Bates, S., Bird, C., de Freitas, A., FoxaH, R., Gilgan, M., Hanic, L., Johnson, G., McCuUoch, A., Odense, P., Pocklington, R., QuiUiam, M., Sim, P., et al. (1989). Pennate diatom Nitzschiapungens as the primary source of domoic acid, a toxin in shellfish from eastern Prince Edward Island, Canada. Can.J. Pish. Aquat. Sci. 46, 1203-1215. 

Montsant, A., Jabbari, K., Maheswari, U., and Bowler, C. (2005). Comparative genomics of the pennate diatom Phaedactylum tricornutum. Plant Physiol. 137, 500—513. 

It is now an accepted paradigm that reheving Fe limitation in HNLC areas fosters the growth and productivity of diatoms (reviewed in Wells, 2003, Fig. 38.2). In most cases, these have been pennate species (Boyd et al., 2000 Cavender-Bares et al., 1999 Coale et al., 2004 Gervais et al., 2002 Hutchins et al., 2002 Martin et al., 1991 Price et al., 1991), although centric diatoms have also bloomed after Fe enrichments in coastal Caftfomia (Firme et al., 2003 Hutchins and Bruland, 1998) and in the SEEDS open ocean experiment in the western subarctic Pacific (Tsuda et al., 2003). These diatom blooms are not necessarily followed by commensurate... 

Figure 14 Response of different phytoplankton groups in the iron fertilized patch (closed symbols) relative to outside the patch (open symbols) of IronEx II in the equatorial Pacific Ocean. Normalized mean pigment fluorescence per cell is orange fluorescence for Synechococcus and red for Prochlorococcus and pennate diatoms. Fluorescence and cell abundance are normalized to values outside the patch (after Cavender-Bares et al, 1999).

According to Droop (1974), species having photosynthetic pigments sometimes show also heterotrophy. However, there is some discussion as to the extent of this phenomenon in relation to phototrophy, because obligate phototrophy cannot always be conclusively demonstrated. Khoja and Whitton (1971) list 17 heterotrophic Cyanophyceae out of a collection of 24, and many littoral pennate diatoms have been shown to be facultative chemotrophs (Lewin and Lewin, 1960 Lewin and Hellebust, 1975). Droop... 

Lewin, J.C. and Hellebust, J.A., 1975. Heterotrophic nutrition of the marine pennate diatom Nauicula pavillardi Hustedt. Can. J. Microbiol., 21 (9) 1335—1342. 

After the finding of P. multiseries, screenings of pennate diatom that produces DA were performed mainly in temperate and cold-water areas, and resulted in reporting several kinds of Pseudo-nitzschia spp. as described in the next section (Table 19.1). 

Bates, S. S., et al. Pennate diatom Nitzschia pungens as the primary source of domoic acid, a toxin in shellfish from eastern Prince Edward Island, Canada. Can. J. Fish. Aquat. Set, 46, 1203-1215 (1989). 

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