The Component Combined Amino Acids Of Some Marine Diatoms

Chuecas, L.; Riley, J.P.

doi:10.1017/s0025315400046440

Cited by 31 publications

(12 citation statements)

References 5 publications

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“…This value is not valid because it corresponds to that of animal protein. The correct conversion factor for phytoplankton is 5.8 reported by Fraga and Pérez (1990), who obtained the value from a data set of 175 amino acid samples and is close to the value of 5.6 recorded by Chuecas and Riley (1969) for diatoms. On the other hand, to estimate Prt using a factor of 5.8, it is necessary to multiply this value by the 80% of total N in order to remove the N-contribution from chlorophyll and nucleic acids.…”

Section: Discussionsupporting

confidence: 83%

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Rı́os¹,

Fraga²,

Pérez³

et al. 1998

Sci. Mar.

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SUMMARY: Elemental (C, H, O, N, Si, P) and biochemical composition (proteins, carbohydrates, lipids, phosphorus compounds, chlorophyll and opal) in particulate organic matter, diatoms, other autotrophs, heterotrophs and detritus from natural plankton were established simultaneously by measuring relatively few components. Using standard techniques in marine chemistry on board ship, it is possible to infer a great deal about the composition and condition of the plankton. In addition, the organic matter content in terms of cell volume was determined for each group of plankton. Variation of chemical composition with depth was also considered. The ratio carbohydrates/lipids (Cbh/Lip) was used as an indicator of the chemical quality of the plankton.

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Section: Discussionsupporting

confidence: 83%

Untitled

Rı́os¹,

Fraga²,

Pérez³

et al. 1998

Sci. Mar.

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“…3b than can be predicted from the amount of ammonium assimilation. Based on a protein composition of 14% N by weight in P. tricornutum (Cheucas and Riley 1969), the measured protein value in these cells was 2.4-fold greater than the value predicted from the total amount of ammonium-N assimilated over the period of the experiment. It is possible that these cells are synthesizing a carbon-rich complement of proteins; certainly the protein composition in cells that are not dividing is unlikely to be the same as the composition in those cells that are actively growing.…”

Section: Discussionmentioning

confidence: 72%

Arrest of cell division but not protein synthesis in sodium-deficient cells of the marine diatom Phaeodactylum tricornutum Bohlin

Larson

Rees

1994

Planta

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Abstract. Cell division in the marine diatom Phaeodactylure tricornutum was prevented when cultures were maintained in the absence of sodium, regardless of the nitrogen status of the cells or medium. Addition of 10 mM ammonium and 50 mM sodium to cultures preconditioned in nitrogen and sodium-deficient medium for 5 d led to a recovery in cell division and chlorophyll a, and net protein synthesis. Sodium added in the absence of ammonium led to a recovery in cell division, but not net protein synthesis. Ammonium added in the absence of sodium was partially assimilated (as NH3) and resulted in a small amount of protein synthesis, but without cell division. This effect was enhanced if the cells had lower protein quotas prior to ammonium addition, with total consumption of the added 1 mM ammonium and appreciable net protein synthesis. Respiration was enhanced by 1 or 10 mM ammonium or 10 mM methylammonium addition to nitrogen-deficient cultures maintained in the presence or absence of sodium. In contrast to respiration, photosynthesis was inhibited by these additions in sodium-replete cultures, but was enhanced in sodium-deficient cultures.

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“…Release of free amino acids by zooplankton has been found in several investigations (Johannes and Webb 1970, Butler et al 1970, Corner and Davies 1971 but also release during grazing must be taken into consideration Davies 1971, Williams 1975). Therefore the sources of the main amino acids can be phytoplankton material, of which the main amino acids were found to be also glycine, serine and alanine along with aspartic and glutamic acid and leucine (Chuecas andRiley 1969, Hecky et al 1973), as weil as zooplankton, since a similar amino acid dominance was found for Calanus helgolandicus (Cowey and Corner 1963). In short, at this phase decomposition processes were proceeding at the depths where high amino acid concentrations were observed.…”

Section: Discussionmentioning

confidence: 90%

“…11). The increase of up to 40 nmol dm-3 during the phytoplankton maximum was caused by the phytoplankton bloom, since the main compounds of this very labile fraction are typical for diatoms (Chuecas and Riley 1969). These compounds are octadecahexaenoic and eicosapentaenoic acids.…”

Section: Discussionmentioning

confidence: 99%