Lipids of four species of freshwater chrysophytes

doi:10.1016/0031-9422(88)80272-3

Phytochemistry

Volume 27, Issue 4, 1988, Pages 1053-1059

https://doi.org/10.1016/0031-9422(88)80272-3 Get rights and content

Abstract

Hydrocarbons, alkyl and steryl esters, free sterols, triacylglycerols and free fatty acids were extracted from four species of cultured freshwater chrysophytes. 21:6 and 21:5 alkenes were identified in two species which also contained the presumed C₂₂ polyenoic fatty acid precursors. Even carbon number (C₂₈-C₃₈) saturated and unsaturated alkyl esters occurred, together with esters of phytol, in all species. The dominant free sterol was either 24-ethylcholesta-5,22E-dien-3β-ol or 24-ethylcholest-5-en-3β-ol; steryl esters showed a predominance of the same steryl moiety, identified by GC-MS analysis, as that dominant in free sterols from the same algal species. The presence of unsaturated acyl groups linked to steryl esters from Synura uvella was demonstrated by trans-esterification. The acyl composition of triacylglycerols (TG), determined after transesterification, showed the absence of unsaturation in TG from Mallomonas caudata but ca 50% of unsaturated acyl groups in two species. Determination of the molecular composition of intact TG by GC-MS revealed the presence of lower homologues containing a C₄ acyl group in Dinobryon divergens and M. caudata. Free fatty acids showed high relative abundances of 14:0 and polyenoic acids.

References (41)

R.F. Lee et al.
Phytochemistry
(1971)
N. Robinson et al.
Phytochemistry
(1987)
M. Rohmer et al.
Steroids
(1980)
E.I. Mercer et al.
Phytochemistry
(1974)
T. Cavalier-Smith
Biosystems
(1981)
P. Kalo et al.
J. Chromatogr.
(1986)
L. Avivi et al.
Comp. Biochem. Physiol.
(1967)
R.P. Collins et al.
Comp. Biochem. Physiol.
(1969)
D. Raederstorff et al.
Phytochemistry
(1984)
P.A. Cranwell
Geochim. Cosmochim. Acta
(1985)

I.T. Marlowe et al.

J.K. Volkman

Org. Geochem.

(1986)

M. Parke et al.

J. Mar. Biol. Ass. U.K.

(1976)

I.T. Marlowe et al.

Br. Phycol. J.

(1984)

J.P. Smol et al.

Nature

(1984)

J. Kristiansen

Br. Phycol. J.

(1986)

F. Juttner

Appl. Environ. Microbiol.

(1981)

J.A. Erwin

(1973)

G.W. Patterson

Lipids

(1971)

P. Bourrelly

Cited by (30)

C<inf>30</inf> and C<inf>31</inf> steranes in Permian fossil conifers Protophyllocladoxylon
2022, Applied Geochemistry
Citation Excerpt :
Absolute amounts of terrigenous organic matter in the conifer trunk samples might be disproportionately overestimated on the basis of n-alkanes, as land plants typically contain higher proportions of n-alkanes than aquatic organisms (Meyers and Ishiwatari, 1993). Additionally, C29 steranes may also have algal sources as the C29 sterols have been also reported in specific microalgae, such as freshwater Chrysophyceae (Cranwell et al., 1988; Volkman et al., 1998), freshwater Eustigmatophyceae (Volkman et al., 1998, 1999), and green microalgae of Chlorophyceae (Volkman et al., 1998). A prokaryotic origin of the C30 4-methylsteranes is still possible, although little organic matter from the trunk samples is derived from bacteria, as indicated by extremely low abundance or absence of hopanes in all the conifer trunk samples and because hopanoids are highly specific biomarkers of a bacterial origin.
Steroids with alkyl groups at C-2 and C-3 are not known yet in any living organism, while 4-methylsteranes are previously thought specific to 4-methylsteroids bio-synthesized by limited types of organisms, such as dinoflagellates, microalgae, and certain bacteria. Here we investigate the occurrence of C₃₀ 2α-, 3β-, 4α-methyl-24-ethylcholestanes, C₃₁ 3β,24-diethylcholestanes, and 3,4-dimethyl-24-ethylcholestane, which are tentatively identified in fourteen fossil conifer Protophyllocladoxylon trunk samples from the upper Permian Wutonggou and Guodikeng formations in northwest China. In contrast to the paucity of alkyl steranes in the background sediments, abundant C₃₀ 4α-methyl-24-ethylcholestanes in fossil conifers from diverse fluvial–lacustrine environments suggest that conifers were the most likely biological origin for the 4-methyl steranes in conifer trunk samples, although origins from associated fungi might also be possible. Alternatively, these C-4 methyl steranes might have possible algal or prokaryotic origins. It is noteworthy that diagenetic methylation or bacterial alkylation at early stages of diagenesis during burial may have caused a re-arrangement of classical 24-ethylsterols that were bio-synthesized by plants to generate C-2 and C-3 alkylated steranes. This study reports the presence of 4-methylsteranes in conifer fossils for the first time, pointing toward a likely origin from higher plants. This study also provides the first report of C-2 and C-3 alkylated steranes in plant fossils, a.llowing for the possibility that plants may produce functionalised sterol precursors of orphan alkylsteranes that are abundant in geological sediments but whose functionalised precursors are not known from any living organisms.
Natural and anthropogenically driven changes in the n-alkanols of lake sediments and implications for their use in paleoenvironmental studies of lakes
2021, Catena
Citation Excerpt :
Short-chain n-alkanols form via hydrolysis of wax esters (Parrish, 1988) and are widely ascribed to phytoplankton or zooplankton sources (Sargent et al., 1977; Wakeham et al., 1980, 1984; Robinson et al., 1984; Meyers et al., 1984; Fernandes et al., 1999a; Hu et al., 2009; He et al., 2014; Guo et al., 2019). For example, chlorophytes and chrysophytes contain short-chain n-alkanols dominated by either C18 or C16 (Smith et al., 1983; Rezanka and Podojil, 1986; Cranwell et al., 1988, 1990; Grimalt et al., 1991; Bechtel and Schubert, 2009; Hu et al., 2009; Holtvoeth et al., 2010). However, other reports suggest that short-chain n-alkanols are not source-specific (Muri et al., 2004) and they may also be contributed by floating aquatic macrophytes such as Utricularia sp. (Jaffé et al., 2001).
In order to examine how natural backgrounds and anthropogenic activities influenced the n-alkanol profiles of lake sediments, abundances and compositions of n-alkanols were determined in sediment cores taken from four lakes with notable differences in depth, nutrient level, transparency, water residence time and human impact. The results indicate the short-chain n-alkanols (C₁₄, C₁₆ and C₁₈) are generally more abundant in sediments from eutrophic lakes than in oligotrophic bodies, due to greater inputs from algae and zooplankton. In individual lakes, however, high levels of short-chain n-alkanols were not always recorded in sediments of relatively eutrophic phases because contributions from zooplankton can be significant even if the lake remains relatively oligotrophic. The >C₂₀ n-alkanol profiles varied markedly between shallow and deep lakes. A prevalence of long-chain compounds (C₂₆, C₂₈, C₃₀ and C₃₂) was observed in shallow lakes and is attributable to terrestrial organic matter (OM) carried by inflowing rivers, whose relatively huge annual input is evidenced by the short water residence time in these lakes. Sediments from deep lakes were dominated by middle-chain n-alkanols (C₂₀, C₂₂ and C₂₄) as a result of significant input from submersed macrophytes, which achieve high productivity in the clear, sunlit water. In shallow lakes, (C₂₆ + C₂₈)/(C₂₂ + C₂₄) n-alkanol ratios in sediments were greatly dependent on anthropogenic eutrophication and aquaculture via their influence on the productivity of submersed macrophytes.
Source, sink and preservation of organic matter from a machine learning approach of polar lipid tracers in sediments and soils from the Yellow River and Bohai Sea, eastern China
2021, Chemical Geology
Citation Excerpt :
Monounsaturated fatty acids (MUFAs), dominated by C16:1 ω7 (ω is the number of double bonds), C18:1 ω9 and C22:1 ω11, were detected to be relatively minor components of total FAs. Generally, C16:1 ω7 could be derived from microalgae and diverse bacteria (Volkman, 2003), while C18:1 ω9 could be present in microalgae and zooplankton (Cranwell et al., 1988; Wakeham and Beier, 1991), and C22:1 ω11 is a significant component of the wax esters in zooplankton (Graeve et al., 1994; Falk-Petersen et al., 2002). Abundant branched fatty acids (br-FAs) were detected in these samples.
Transport and transformation of organic matter (OM) from the river to the marginal sea is a significant part of the global carbon cycle. Biomarkers are of indispensable advantage in precisely identifying the origin of OM that is crucial to understand the organic carbon cycle. Application of more biomarker molecules with mutually confirmable information commonly implies stricter constraint of the source but also brings challenges to the data analysis and interpretation due to a large amount of molecular information. Here we used random forest (RF) classification models to analyze 123 polar lipid biomarkers of six categories, including fatty alcohols, fatty acids, alkan-2-ones, steroids, triterpenoids, and 1-O-monoalkylglycerol ethers (MAGEs) from the sediments and soils in the Yellow River and the Bohai Sea of eastern China. The environmental specificity of biomarkers was assessed based on the effective distinguishment of samples from different habitats by RF models. The sources of polar lipid biomarkers were constrained according to their environmental specificity, and four genetic classifications, i.e., bacteria, algae and zooplankton, terrestrial higher plants, and anthropogenic input were identified. The spatial distribution of OM sources provides a reasonable scheme of the sink for biospheric OM in this typical “land-river-ocean” system. A type of MAGEs as the most important variables for the RF models was effectively used to be a potential bottom-water oxygen proxy to assess the preservation of OM, and ca. 37% of marine in-situ fresh OM was estimated to decompose under varying redox conditions in the surface sediments of Bohai Sea.
Influence of human activity on the abundance, distribution and origin of fatty acids in sediments of two shallow lakes and implications for paleolimnological studies
2020, Ecological Indicators
Citation Excerpt :
The ratio of C18:1 ω7/C18:1 ω9 has been used to trace bacterial reworking of planktonic material (Wakeham et al., 1997; Bechtel and Schubert, 2010; Chen et al., 2019). However, C18:1 ω7 is also found in some freshwater algae (e.g. Dinobryon divergenes and Mallomonas caudata) and C18:1 ω9 could be present in bacteria and zooplankton (Cranwell et al., 1988; Wakeham and Beier, 1991; Wakeham, 1995; Wakeham et al.,1997; Prartono and Wolff, 1998; Birgel et al., 2004). In CD-1, abundances of C18:1 varied similarly to those of C22:1 (R2 = 0.92, n = 35, Fig. 7b and d).
During the past few decades, the majority of shallow lakes in the Yangtze River basin (Eastern China) have been impacted by heavy discharges of sewage and the intensification of aquaculture. These activities have significant potential to alter aquatic ecosystems and these changes may be reflected in the composition of lipid biomarkers in sediments at the time. In order to evaluate this effect, the abundances and distribution of fatty acids (FAs) were measured in ²¹⁰Pb dated sediment cores from two anthropogenically impacted shallow lakes in the Yangtze River basin, Changdang and Taibai. Results from Lake Changdang revealed an extreme enrichment of zooplankton-derived C22:1 ω11 in sediments, with C22:1 ω11/n-C16 ratios reaching ~1.6 on average. This unusual distribution may have been caused by zooplankton blooms in the lake in the years before aquaculture was developed. Elevated abundances of C18:1 ω9 and short-chain n-alkanoic acids observed in pre-1977 sediments might be also derived from zooplankton. After 1977, FAs of zooplankton origin in Lake Changdang greatly declined in abundance, coincident with the introduction of planktivorous fish. Meanwhile, inputs of FAs from submerged/floating macrophytes, bacteria and algae increased as a result of eutrophication and reduced grazing pressure from zooplankton. In Lake Taibai, abundances of C22:1 ω11 were greatly reduced in all sediments and accounted for 38% of n-C16 on average, reflecting comparatively smaller inputs of zooplankton FAs owing to the earlier establishment of aquaculture in the lake. Relative enrichment of polyunsaturated FAs (PUFAs) and branched FAs (Br-FAs) in the sediments was attributed to high inputs of algal and bacterial organic matter (OM) in response to reduced predation and grazing by zooplankton. Rapid increases in PUFAs and Br-FAs in post-1970 sediments were driven by eutrophication in this period.
Co-occurrence of long chain diols, keto-ols, hydroxy acids and keto acids in recent sediments of Lake El Junco, Galápagos Islands
2011, Organic Geochemistry
Citation Excerpt :
Saturated and monounsaturated wax esters usually co-eluted during our analyses of El Junco sediments. Their molecular compositions were derived from both the GC–MS analysis of fatty acids and fatty alcohols released by saponification and the relative intensities of the [RCO2H2]+ ions in summation spectra obtained from each GC peak, as previously reported (Cranwell et al., 1988). Both alcohols and acids exhibited ranges between C13 and C20, while iso-branching was limited to the C16 and C18 compounds.
Lipid biomarkers in lacustrine sediments provide valuable information about lake history and environmental change. Here we report the occurrence of a unique set of lipid biomarkers from a freshwater crater lake, El Junco, in the Galápagos. In addition to previously reported alkadienes, botryococcenes and lycopadienes indicative of Botryococcus braunii A, B and L races, we find highly branched C₂₅ isoprenoids (HBIs) from diatoms, monomethyl alkanes likely from insect epicuticular waxes, long chain alkenols, diols and a triol, keto-ols, hydroxy acids and keto acids. Saturated and mono-unsaturated long chain diols from C₃₀–C₃₆ had terminal hydroxyl groups and hydroxyl groups between the ω16 and ω20 positions. Vicinal diols with hydroxyl groups at ω9 and ω10 were likely from the floating fern Azolla. C₃₀–C₃₆ keto-ols, mid-chain hydroxy and keto acids had mid-chain functional groups at similar positions to the diols, suggesting common origins. The predominance of ω20-hydroxy acids and diols, together with 20,21-dihydroxy-nonacosanoic acid is indicative of an Azolla source, while ω16 and ω18 hydroxy acids and diols imply a microalgal source.
Temperature dependency of long-chain alkenone distributions in Recent to fossil limnic sediments and in lake waters
2001, Geochimica et Cosmochimica Acta
Distribution patterns of C₃₇ and C₃₈ polyunsaturated long-chain alkenones (LCAs) serve as proxies for the determination of paleotemperatures for marine surface waters. We studied Recent/Subrecent and Late Glacial/Holocene sediments from Germany, Austria, Russia, and the U.S. to test for a correspondence between LCA distribution and surface water temperature in limnic systems. Previously, reports of LCA occurrence were restricted to sediments of 6 wide distributed freshwater and alkaline lakes. In this study 13 of 27 investigated lakes contained LCAs in surface sediments with concentrations varying between 12 to 205 μg/g TOC. Late Glacial to Holocene sediment sequences from Lake Steisslingen and Lake Wummsee, (Germany), Lake Pichozero (Russia), and Brush Lake (U.S.A.) contained abundant LCAs with averaged concentrations of 33 to 7536 μg/g TOC. For the first time we observed the occurrence of LCAs within in the water column of oligotrophic Lake Stechlin (NE-Germany). Alkenones were restricted to the zone of maximum chlorophyll concentration within the water column indicating that LCAs have a biosynthetic origin and can be attributed to phototrophic (micro)algae. Attempts to identify the producing organism, however, were not successful. Culture experiments allow various phytoplankton to be excluded as producers. Alkenone-producing algae are evidently of small size, hindering microscopical identification. LCAs commonly occur in high concentrations in Late Glacial sediments, mainly during the cold period of the Younger Dryas, whereas the Holocene usually is devoid of polyunsaturated alkenones. The episodic occurrence of LCAs restricts their utility as proxies for continuous geological records. Furthermore, lack of microscopical verification and the episodic distribution allow for different producers of unsaturated alkenones in Recent and Late Glacial sediments. An empirical relationship between LCA distribution and temperature was observed. In fossil sediments from Lake Steisslingen, there is a good correspondence between Uk37 and the temperature-controlled δ¹⁸O isotope ratio of lake chalk. Comparison of LCA patterns obtained from the uppermost centimetres of lake sediments with averaged summer surface water temperatures of the lakes studied, demonstrates a trend of covariance (r²: Uk′37 = 0.90, Uk37 = 0.67; n = 9). Hence, the same mechanism that causes temperature-dependence of LCA patterns in marine systems might be effective in limnic settings. Identification of alkenone producers and their culture under controlled temperature are still mandatory before LCAs can be routinely applied as paleotemperature proxy in limnic systems.

View all citing articles on Scopus

View full text

Lipids of four species of freshwater chrysophytes

Abstract

Phytochemistry

Phytochemistry

Steroids

Phytochemistry

Biosystems

J. Chromatogr.

Comp. Biochem. Physiol.

Comp. Biochem. Physiol.

Phytochemistry

Geochim. Cosmochim. Acta

Org. Geochem.

J. Mar. Biol. Ass. U.K.

Br. Phycol. J.

Nature

Br. Phycol. J.

Appl. Environ. Microbiol.

Lipids