Nitzschia alba

Lewin, J., and Chen, C. H. Silicon metabolism in diatoms. VI. Silicic acid uptake by a colorless marine diatom, Nitzschia alba Lewin and Lewin. J. Phycol. 4, 161-166 (1968). 

In addition to sulfoquinovosyldiacylglycerol, the marine diatom Nitzschia alba has been found to contain a sulfonium analog of phosphatidylcholine, phosphatidylsulfocholine (14). This lipid has two methyl groups attached to the sulphur atom, and it substitutes completely for phosphatidylcholine in Nitzschia alba. In other marine diatoms and algae, both lipids have been found (15). 

Anderson R, Kates M, Volcani BE. Identihcation of the sulfolipids in the non-photosynthetic diatom Nitzschia alba. Biochim. Bio-phys. Acta 1978 528 89-106. 

The major component, 1-frustulin, is one of a number of isoforms of a 75 kDa protein that is immunologically related to proteins extracted from the cell walls of other diatom species, namely Navicula pelliculosa, Nitzschia alba, N. angularis and Phaeodactylum tricornutum. 

Even carbon atom normal olefins are significant components of the nonphotosynthetic diatom Nitzschia alba the n-Ci6 2 represents 33.8% of total n-alkanes + n-alkenes, the n-C,g 2 20.4%, the n-Cjg 2 9.3% (Tomabene et al., 1974). The predominance in Nitzschia alba of even-carbon numbered olefins, as compared with the high content of odd-carbon numbered olefinic hydrocarbons found in other algae is unique and suggests that this diatom may have an unusual biosynthetic pathway for hydrocarbons. 

Tornabene, T.G., Kates, M. and Volcani, B.E., 1974. Sterols, aliphatic hydrocarbons, and fatty acids of a nonphotosynthetic diatom, Nitzschia alba. Lipids, 9 279—284. 

In certain organisms, e.g. the non-photosynthetic diatom Nitzschia alba, lecithine was found to be replaced by its sulphonium analogue (a phos-phatidyl-S,S-dimethylmercaptoethanol) as cell membrane component (Anderson et al., 1976) it was concluded that S-containing amino acids (e.g. cysteine, methionine) rather than serine probably act as primary precursors of the glycerophospholipids and sphingolipids which are involved in the formation of hydrophobic layers in membrane structures. 

Recently, the chemical synthesis of 5/i-3-phosphatidylsulfocholine has been reported (Tremblay and Kates, 1979). Biosynthesis of the sulfocholine moiety in Nitzschia alba has been suggested to occur via the deamination, oxidative decarboxylation, and methylation of methionine. In addition, the 1-deoxyceramide-1-sulfonate compound was proposed to be synthesized in a manner analogous to sphingosine, with cysteine replacing serine (Anderson et a/., 1979). 

STUDIES ON THE BIOSYNTHESIS OF PHOSPHATIDYLSULFOCHOLINE AND DEOXYCERAMIDESULFONIC ACID IN THE DIATOM NITZSCHIA ALBA... 

The non-photosyntnetic diatom, Nitzschia alba, contains phosphati-dylsulfochollne (PSC) as the major membrane phospholipid, which completely replaces phosphatidylcholine (PC) [1,2]. The sulfonlum analogue (PSC) also occurs in photosynthetic diatoms, which however contain... 

Table 3. INCORPORATION OF VARIOUS PRECURSORS INTO DEOXYCERAMIDE SULFONIC ACID (DCS) IN NITZSCHIA ALBA ...

Anderson, R., Kates, M. and Volcanl, B.E. (1978), Identification of the sulfollplds In the non-photosynthetlc diatom Nitzschia alba, Blochem.Blophys.Acta 528,89-106. 

The sulfoqtxinovosyldiglycerides are not the only sulfo-lipids found in the diatoms, whether marine or freshwater, and the presence of these sulfolipids is probably the principal characteristic of these organisms. In addition to the SQDGs, which are ubiquitous, the diatoms contain deoxyceramide-l-sulfonic acids and phosphatidylsulfocho-lines (PSCs) (Bisseret et al, 1984). Two examples of these compounds isolated from Nitzschia alba are presented below (Kates, 1989). 

Navicula pdliculosa, Nitzschia alba Kates and Volcani, 1966 Anderson, Kates, and Volcani, 1978... 

More recent reports, however, suggest that some protozoans do contain sialic acid components. The marine diatom, Nitzschia alba, was found to possess components containing sialic acid, with the highest concentration in a light smooth membrane preparation (Sullivan and... 

Sullivan, C. W., and Volcani, B. E., 1974, Isolation and characterization of plasma and smooth membrane of the marine diatom Nitzschia alba, Arch. Biochem. Biophys. 163 29. 

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