A comprehensive study of sterols in marine diatoms (Bacillariophyta): Implications for their use as tracers for diatom productivity

Diatoms are one of the most important organisms contributing to aquatic primary productivity and their sterols are frequently used as markers for their presence and abundance. In this study, the sterol composition of >100 diatom cultures was analyzed and its distribution was compared to the diatom phylogeny to identify typical diatom biomarkers. Forty‐four sterols were detected, 11 of them being commonly present as major sterols (contributing >10% to the total sterols). 24‐Methylcholesta‐5,24(28)‐dien‐3β‐ol is the most common sterol in diatoms, being present in 67% of all cultures analyzed, followed by the Δ5 sterols, cholest‐5‐en‐3β‐ol (cholesterol), 24‐methylcholest‐5‐en‐3β‐ol, and 24‐ethylcholest‐5‐en‐3β‐ol. 24‐Methylcholesta‐5,22E‐dien‐3β‐ol, previously suggested to be specific for diatoms, was only the fifth most common sterol; this sterol was absent in some of the major diatom groups, and high relative concentrations seem to be restricted to pennate diatoms. No sterols are restricted to specific phylogenetic groups of diatoms. Cluster analyses, however, do reveal distinct sterol distributions: Thalassiosirales typically contain high relative abundances of 24‐methylcholesta‐5,24(28)‐dien‐3β‐ol, high relative abundances of cholesta‐5,22E‐dien‐3β‐ol are typical for Cymatosirales, high relative abundances of 24‐ethylcholesta‐5,22E‐dien‐3β‐ol are characteristic for related Amphora, Amphiprora, and Entomoneis species, and a combination of high relative abundances of 24‐methylcholest‐5‐en‐3β‐ol, 24‐methylcholesta‐5,24(28)‐dien‐3β‐ol, and 24‐ethylcholest‐5‐en‐3β‐ol is typical for Attheya species. High contributions of 24‐methylcholesta‐5,22E‐dien‐3β‐ol (>50% of all sterols) seem to be restricted to pennate diatoms. None of the major sterols found in diatoms can be used as an unambiguous diatom biomarker because all of them have been reported as common sterols in other algal groups.

[1]  G. Muyzer,et al.  PHYLOGENETIC POSITION OF ATTHEYA LONGICORNIS AND ATTHEYA SEPTENTRIONALIS (BACILLARIOPHYTA) 1 , 2009, Journal of phycology.

[2]  Stefan Schouten,et al.  Occurrence and biomarker potential of 23-methyl steroids in diatoms and sediments , 2009 .

[3]  Kazuki Saito,et al.  Dual biosynthetic pathways to phytosterol via cycloartenol and lanosterol in Arabidopsis , 2009, Proceedings of the National Academy of Sciences.

[4]  D. Rabosky,et al.  Diversity dynamics of marine planktonic diatoms across the Cenozoic , 2009, Nature.

[5]  Stefan Schouten,et al.  Occurrence of gorgosterol in diatoms of the genus Delphineis , 2009 .

[6]  D. Mann,et al.  MOLECULAR EVIDENCE CONFIRMS SISTER RELATIONSHIP OF ARDISSONEA, CLIMACOSPHENIA, AND TOXARIUM WITHIN THE BIPOLAR CENTRIC DIATOMS (BACILLARIOPHYTA, MEDIOPHYCEAE), AND CLADISTIC ANALYSES CONFIRM THAT EXTREMELY ELONGATED SHAPE HAS ARISEN TWICE IN THE DIATOMS 1 , 2008, Journal of phycology.

[7]  T. Kuroiwa,et al.  A cryptic algal group unveiled: a plastid biosynthesis pathway in the oyster parasite Perkinsus marinus. , 2008, Molecular biology and evolution.

[8]  U. Sorhannus.  A nuclear-encoded small-subunit ribosomal RNA timescale for diatom evolution , 2007 .

[9]  G. Muyzer,et al.  On the origin of 24-norcholestanes and their use as age-diagnostic biomarkers , 2007 .

[10]  C. Delwiche,et al.  Plastid genes in a non-photosynthetic dinoflagellate. , 2007, Protist.

[11]  D. Mann,et al.  The origin and evolution of the diatoms: their adaptation to a planktonic existence , 2007 .

[12]  M. Hartmann,et al.  Sterol composition ofPhaeodactylum tricornutum as influenced by growth temperature and light spectral quality , 1996, Lipids.

[13]  Sebastiaan W. Rampen,et al.  Effect of diatom nutrient limitation on copepod development: role of essential lipids , 2005 .

[14]  Nicholas H. Putnam,et al.  The Genome of the Diatom Thalassiosira Pseudonana: Ecology, Evolution, and Metabolism , 2004, Science.

[15]  Linda K. Medlin,et al.  Evolution of the diatoms: V. Morphological and cytological support for the major clades and a taxonomic revision , 2004 .

[16]  M. Rohmer,et al.  Isoprenoid biosynthesis in the diatoms Rhizosolenia setigera (Brightwell) and Haslea ostrearia (Simonsen). , 2004, Proceedings of the National Academy of Sciences of the United States of America.

[17]  W. Kooistra,et al.  Molecular phylogeny and morphology of the marine diatom Talaroneis posidoniae gen. et sp. nov. (Bacillariophyta) advocate the return of the Plagiogrammaceae to the pennate diatoms , 2004 .

[18]  J. Volkman,et al.  Sterols in microorganisms , 2002, Applied Microbiology and Biotechnology.

[19]  J. Schwender,et al.  Chlorophyta exclusively use the 1-deoxyxylulose 5-phosphate/2-C-methylerythritol 4-phosphate pathway for the biosynthesis of isoprenoids , 2001, Planta.

[20]  A. Mühlebach.  Sterole im herbstlichen Weddellmeer (Antarktis) : großräumige Verteilung, Vorkommen und Umsatz = Sterols in the autumnal Weddell Sea (Antarctica): large-scale distribution, occurrence, and turnover , 1999 .

[21]  E. Tegelaar,et al.  24-norcholestanes as age-sensitive molecular fossils , 1998 .

[22]  C. Billard,et al.  STEROLIC BIOMARKERS IN MARINE PHYTOPLANKTON. II. FREE AND CONJUGATED STEROLS OF SEVEN SPECIES USED IN MARICULTURE , 1998 .

[23]  D. M. Nelson,et al.  Production and dissolution of biogenic silica in the ocean: Revised global estimates, comparison with regional data and relationship to biogenic sedimentation , 1995 .

[24]  S. M. Barrett,et al.  STEROLS OF 14 SPECIES OF MARINE DIATOMS (BACILLARIOPHYTA) 1 , 1995 .

[25]  S. M. Barrett,et al.  Geochemical significance of the occurrence of dinosterol and other 4-methyl sterols in a marine diatom , 1993 .

[26]  C. Djerassi,et al.  Biosynthetic studies of marine lipids. 33. Biosynthesis of dinosterol, peridinosterol and gorgosterol: unusual patterns of bioalkylation in dinoflagellate sterols , 1991 .

[27]  W. Lusby,et al.  Sterols of some diatoms , 1991 .

[28]  C. Djerassi,et al.  Dinoflagellates cyclize squalene oxide to lanosterol , 1991 .

[29]  G. Hallegraeff,et al.  Lipids in marine diatoms of the genus Thalassiosira: Predominance of 24-methylenecholesterol , 1988 .

[30]  J. Volkman.  A review of sterol markers for marine and terrigenous organic matter , 1986 .

[31]  G. McFadden,et al.  Sterols and fatty acids of an antarctic sea ice diatom, Stauroneis amphioxys , 1981 .

[32]  W. Meinschein,et al.  Sterols as ecological indicators , 1979 .

[33]  R. Morris,et al.  Sterols of the phytoplankton—effects of illumination and growth stage , 1979 .

[34]  D. Orcutt,et al.  Sterol, fatty acid and elemental composition of diatoms grown in chemically defined media. , 1975, Comparative biochemistry and physiology. B, Comparative biochemistry.

[35]  A. Kanazawa,et al.  The Occurrence of Brassicasterol in the Diatoms, Cyclotella nana and Nitzschia closterium , 1971 .