Effects of light intensity, CO2 and nitrogen supply on lipid class composition of Dunaliella viridis

Lipid class composition of Dunaliella viridis Teodoresco was analysed using thin layer chromatography coupled with flame ionisation detection (TLC/FID technique). D. viridis was cultured under four different photon fluence rates and in darkness, and under two different conditions of CO₂ supply (atmospheric and 1%) with and without nitrogen sufficiency. Nine lipid classes were identified and quantified. Total lipids per cell and acetone-mobile polar lipids decreased with light, while the percentage of sterols and triglycerides increased with increasing irradiance. Total phospholipids increase was related with growth rate while hydrocarbons, wax esters and sterol esters accumulated in darkness. There were almost no changes in total lipids per cell because of nitrogen limitation; however, nitrogen limitation led to higher changes in lipid class composition under 1% CO₂ than under atmospheric CO₂ levels. The main reserve lipid, triglycerides, accumulated in high amounts under 1% CO₂ and nitrogen limitation, increasing from 1% to 22% of total lipids. The ratio sterols/acetone-mobile polar lipids could be an index of the 'light status' independently of nitrogen limitation, while the ratio triglycerides/total phospholipids could indicate any physiological stress uncoupling C and N metabolism and affecting the growth rate. This revised version was published online in June 2006 with corrections to the Cover Date.     

Effects of CO2 and nitrogen supply on the biochemical composition of Ulva rigida with especial emphasis on lipid class analysis

Lipid class composition was analysed in the green macroalga Ulva rigida grown under normal (350 ppm) and high (10,000 ppm) CO₂ levels, and in nitrate saturated and nitrogen limited conditions. A new protocol for the extraction of lipids has been defined. Culture conditions altered the fate of assimilated carbon, and significant changes were observed in protein and total lipid content in particular. A CO₂-enriched atmosphere conditioned the effects of nitrogen limitation on lipid class composition, revealing deep qualitative changes in carbon metabolism. Triglycerides accumulated at high CO₂ and under nitrogen limitation, while chloroplast-related lipids showed an inverse response. Changes in phospholipids could be related to carbon availability as they did not respond to nitrogen limitation. The ratio sterols/acetone-mobile polar lipids followed a negative linear relation with the optimum quantum yield for photosynthetic electron transport (F_v/F_m), and was considered as an index of the «light status» of the cell. The specificity of the response of lipid classes to growth conditions in U. rigida emphasizes the potential role of lipid class analyses as a diagnostic tool for environmental stress.     

Photosynthesis of Lipids from CO(2) in Spinacia oleracea

Young expanding spinach leaves exposed to ¹⁴CO₂ under physiological conditions for up to 20 minutes assimilated CO₂ into lipids at a mean rate of 7.6 micromoles per milligram chlorophyll per hour following a lag period of 5 minutes. Label entered into all parts of the lipid molecule and only 28% of the ¹⁴C fixed into lipids was found in the fatty acid moieties, i.e. fatty acids were synthesized from CO₂in vivo at a mean rate of 2.1 micromoles per milligram chlorophyll per hour. Intact spinach chloroplasts isolated from these leaves incorporated H¹⁴CO₃ into fatty acids at a maximal rate of 0.6 micromole per milligram chlorophyll per hour, but were unable to synthesize either the polar moieties of their lipids or polyunsaturated fatty acids. Since isolated chloroplasts will only synthesize fatty acids at rates similar to the one obtained with intact leaves in vivo if acetate is used as a precursor, it is suggested that acetate derived from leaf mitochondria is the physiological fatty acid precursor.     

Biomass production,total protein,chlorophylls, lipids and fatty acids of freshwater green and blue-green algae under different nitrogen regimes

Two green algae (Chlorella vulgaris and Scenedesmus obliquus) and four blue-green algae (Anacystis nidulans, Microcystis aeruginosa, Oscillatoria rubescens and Spirulina platensis) were grown in 81 batch cultures at different nitrogen levels. In all the algae increasing N levels led to an increase in the biomass (from 8 to 450 mg/l), in protein content (from 8 to 54 %) and in chlorophyll. At low N levels, the green algae contained a high percentage of total lipids (45 % of the biomass). More than 70 % of these were neutral lipids such as triacylglycerols (containing mainly 16:0 and 18:1 fatty acids) and trace amounts of hydrocarbons. At high N levels, the percentage of total lipids dropped to about 20 % of the dry weight. In the latter case the predominant lipids were polar lipids containing polyunsaturated C₁₆ and C₁₈ fatty acids. The blue-green algae, however, did not show any significant changes in their fatty acid and lipid compositions, when the nitrogen concentrations in the nutrient medium were varied. Thus the green but not the blue-green algae can be manipulated in mass cultures to yield a biomass with desired fatty acid and lipid compositions. The data may indicate a hitherto unrecognized distinction between prokaryotic and eukaryotic organisms.     

Methanogenesis and microbial lipid synthesis in anoxic salt marsh sediments

In anoxic salt marsh sediments of Sapelo Island, GA, USA, the vertical distribution of CH₄ production was measured in the upper 20 cm of surface sediments in ten locations. In one section of high marsh sediments, the concentration and oxidation of acetate in sediment porewaters and the rate and amount of¹⁴C acetate and¹⁴CO₂ incorporation into cellular lipids of the microbial population were investigated. CH₄ production rates ranged from <1 to 493 nM CH₄ gram sediment⁻¹ day⁻¹ from intact subcores incubated under nitrogen. Replacement with H₂ stimulated the rate of methane release up to nine fold relative to N₂ incubations. Rates of lipid synthesis from CO₂ averaged 39.2 ×10⁻²nanomoles lipid carbon cm³ sediment⁻¹ hr⁻¹, suggesting that CO₂ may be an important carbon precursor for microbial membrane synthesis in marsh sediments under anoxic conditions. Qualitative measurements of lipid synthesis rates from acetate were found to average 8.7 × 10⁻² nanomoles. Phospholipids were the dominant lipids synthesized by both substrates in sediment cores, accounting for an average of 76.6% of all lipid radioactivity. Small amounts of ether lipids indicative of methanogenic bacteria were observed in cores incubated for 7 days, with similar rates of synthesis for both CO₂ and acetate. The low rate of ether lipid synthesis suggests that either methanogen lipid biosynthesis is very slow or that methanogens represent a small component of total microbial lipid synthesis in anoxic sediments. present address: The University of Maryland,, Chesapeake Biological Laboratory, Box 38, Solomons, MD 20688, USA     

Organic geochemical studies of modern microbial mats from Shark Bay: Part I: Influence of depth and salinity on lipid biomarkers and their isotopic signatures

The present study investigated the influence of abiotic conditions on microbial mat communities from Shark Bay, a World Heritage area well known for a diverse range of extant mats presenting structural similarities with ancient stromatolites. The distributions and stable carbon isotopic values of lipid biomarkers [aliphatic hydrocarbons and polar lipid fatty acids (PLFAs)] and bulk carbon and nitrogen isotope values of biomass were analysed in four different types of mats along a tidal flat gradient to characterize the microbial communities and systematically investigate the relationship of the above parameters with water depth. Cyanobacteria were dominant in all mats, as demonstrated by the presence of diagnostic hydrocarbons (e.g. n‐C₁₇ and n‐C_17:1). Several subtle but important differences in lipid composition across the littoral gradient were, however, evident. For instance, the shallower mats contained a higher diatom contribution, concordant with previous mat studies from other locations (e.g. Antarctica). Conversely, the organic matter (OM) of the deeper mats showed evidence for a higher seagrass contribution [high C/N, ¹³C‐depleted long‐chain n‐alkanes]. The morphological structure of the mats may have influenced CO₂ diffusion leading to more ¹³C‐enriched lipids in the shallow mats. Alternatively, changes in CO₂ fixation pathways, such as increase in the acetyl COA‐pathway by sulphate‐reducing bacteria, could have also caused the observed shifts in δ¹³C values of the mats. In addition, three smooth mats from different Shark Bay sites were analysed to investigate potential functional relationship of the microbial communities with differing salinity levels. The C_25:1 HBI was identified in the high salinity mat only and a lower abundance of PLFAs associated with diatoms was observed in the less saline mats, suggesting a higher abundance of diatoms at the most saline site. Furthermore, it appeared that the most and least saline mats were dominated by autotrophic biomass using different CO₂ fixation pathways.     

不同施氮措施对旱作玉米地土壤酶活性及CO2排放量的影响

对施用速效氮肥(尿素)和缓释氮肥的旱作夏玉米地土壤酶活性及CO2排放量进行分析。结果表明,与不施肥处理比较,不同氮肥种类和施用量均可显著提高土壤脲酶、蔗糖酶、过氧化氢酶活性和CO2的排放量。在整个生育期,尿素与缓释氮肥处理土壤酶活性和土壤CO2排放量表现出相同变化趋势,尿素和缓释氮肥处理土壤CO2平均排放量分别为459.12 mg·m-·2h-1和427.11 mg·m-·2h-1,两者达到显著差异水平(P<0.5)。相关分析表明,土壤脲酶、蔗糖酶和过氧化氢酶活性与土壤CO2排放量呈显著或极显著正相关,相关系数分别为0.79、0.64和0.80。说明相同施氮量缓释氮肥较尿素能有效提高土壤酶活性并降低土壤碳排放量。     

Methanogenesis and microbial lipid synthesis in anoxic salt marsh sediments

In anoxic salt marsh sediments of Sapelo Island, GA, USA, the vertical distribution of CH₄ production was measured in the upper 20 cm of surface sediments in ten locations. In one section of high marsh sediments, the concentration and oxidation of acetate in sediment porewaters and the rate and amount of¹⁴C acetate and¹⁴CO₂ incorporation into cellular lipids of the microbial population were investigated. CH₄ production rates ranged from <1 to 493 nM CH₄ gram sediment⁻¹ day⁻¹ from intact subcores incubated under nitrogen. Replacement with H₂ stimulated the rate of methane release up to nine fold relative to N₂ incubations. Rates of lipid synthesis from CO₂ averaged 39.2 ×10⁻²nanomoles lipid carbon cm³ sediment⁻¹ hr⁻¹, suggesting that CO₂ may be an important carbon precursor for microbial membrane synthesis in marsh sediments under anoxic conditions. Qualitative measurements of lipid synthesis rates from acetate were found to average 8.7 × 10⁻² nanomoles. Phospholipids were the dominant lipids synthesized by both substrates in sediment cores, accounting for an average of 76.6% of all lipid radioactivity. Small amounts of ether lipids indicative of methanogenic bacteria were observed in cores incubated for 7 days, with similar rates of synthesis for both CO₂ and acetate. The low rate of ether lipid synthesis suggests that either methanogen lipid biosynthesis is very slow or that methanogens represent a small component of total microbial lipid synthesis in anoxic sediments. present address: The University of Maryland,, Chesapeake Biological Laboratory, Box 38, Solomons, MD 20688, USA     

EFFECTS OF SILICON DEFICIENCY ON LIPID COMPOSITION AND METABOLISM IN THE DIATOM CYCLOTELLA CRYPTICA1

The effects of silicon deficiency on the metabolism and composition of lipids in Cyclotella cryptica T13L Reimann, Lewin, and Guillard were examined. Silicon-deficient cells had higher levels of neutral lipids (primarily triacylglycerols) and higher proportions of saturated and monounsaturated fatty acids than silicon-replete cells. After 4 h of silicon deficiency, the percentage of newly assimilated NaH¹⁴CO₃ partitioned into lipids increased from 27.6% to 54.1%, whereas the percentage partitioned into chrysolaminarin decreased from 21.6% to 10.6%. In addition, pulse-chase experiments with NaH¹⁴CO₃ indicated that the amount of ¹⁴C in the total cellular lipid fraction increased by 32% after 12 h of silicon deficiency despite the absence of additional photoassimilable ¹⁴C. Therefore, the accumulation of lipids in response to silicon deficiency appears to be due to two distinct processes: (a) an increase in the proportion of newly assimilated carbon partioned into lipids, and (2) a slow conversion of previously assimilated carbon from non-lipid compounds into lipids     

The Effect of Light, Carhon Dioxide, and Nitrogen Nutrition on the Incorporation of S from External Sulphate into Different S-Containing Fractions in Scenedesmus, with Special Reference to Lipid S

The experiments showed that incorporation of S from the sulphate in the medium into normal cells of Scenedesmus was enhanced by light, relatively most in the case of lipid S and least in the inorganic sulphate fraction. The effects of light were, generally, increased by the presence of CO₂ and nitrogen salts. CO₂ did not significantly alter the proportions between the fractions, but the presence of nitrogen increased the formation of protein S more than the synthesis of S-containing lipids.—It is suggested that lipid S is formed as a “sink”, when a step between sulpbite and -SH becomes increasingly rate-limiting in the overall reduction of sulphate. Furthermore, incorporation as SO₄^2? and as lipid S may be regulated by more or less independent processes.     

<Emphasis Type="Italic">Scenedesmus vacuolatus</Emphasis> cultures for possible combined laccase-like phenoloxidase activity and biodiesel production

A key aspect of the industrial development of microalgal production processes is the excessive cost of biomass production. A solution is a combination of biodiesel production and wastewater treatment. The microalga Scenedesmus has a high lipid content and a potential extracellular phenoloxidase activity, which could improve the phycoremediation of phenolic pollutants. In this work, the most suitable growth conditions to obtain this twofold aim were analyzed. First, different strains of Scenedesmus vacuolatus microalga were tested at different pH, salinity and CO₂ concentration in the gas phase. The two most promising strains were then cultivated in autotrophic and heterotrophic conditions, and were investigated in terms of efficient nitrogen removal, fatty acid profile and maximized extracellular phenoloxidase activity in the medium. The results showed two extreme conditions: (1) biomass productivity doubled when photobioreactors were sparged with 5% CO₂ supplemented air with respect to cultures sparged with air (the steady state values of strain 53 were 0.138 g L^?1 day^?1 in the presence of air, and 0.243 in the presence of CO₂ addition), and N-starvation under 5% CO₂enhanced the transesterified fraction of lipids (strain 53 FAME fraction in the presence of N-starvation was 33%, in the presence of nitrogen FAME fraction was 22%); (2) phenoloxidase activity was completely suppressed by presence of 5% CO₂ in the gas phase (strain 53 0.21 U mL^?1), indicating clear catabolite repression for the induction of this enzyme in the algal metabolism.     

<Emphasis Type="Italic">Neochloris oleabundans</Emphasis> UTEX #1185: a suitable renewable lipid source for biofuel production

Energy crises, global warming, and climatic changes call for technological and commercial advances in manufacturing high-quality transportation fuels from unconventional feedstocks. Microalgae is one of the most promising sources of biofuels due to the high yields attained per unit area and because it does not displace food crops. Neochloris oleabundans (Neo) microalga is an important promising microbial source of single-cell oil (SCO). Different experimental growth and lipid production conditions were evaluated and compared by using optical density (540 nm), dry-weight determination, and flow cytometry (FC). Best Neo average biomass productivity was obtained at 30°C under conditions of nitrogen-sufficiency and CO₂ supplementation (N+/30°C/CO₂), with an average doubling time of 1.4 days. The second and third highest productivities occurred with N-sufficient cultures without CO₂ supplementation at 26°C (N+/26°C) and at 30°C (N+/30°C), with doubling times of 1.7 and 2.2 days, respectively. Microbial lipid production was monitored by flow cytometry using Nile red (NR), a lipophilic fluorochrome that possesses several advantageous characteristics for in situ screening near real time (at line). Results showed maximum lipid content (56%) after 6 days of nitrogen depletion under nitrogen starvation without CO₂ supplementation (N−/30°C), followed by N−/30°C/CO₂ and N−/26°C conditions with 52% lipid content, after 5 and 6 days of N starvation, respectively. The adequate fatty acid profile and iodine value of Neo lipids reinforced this microalga as a good source of SCO, in particular for use as biodiesel.     

The effects of nitrogen fertilisation and elevated CO2 on the lipid biosynthesis and carbon isotopic discrimination in birch seedlings (Betula pendula)

The effects of nitrogen (N) fertilisation and elevated [CO₂] on lipid biosynthesis and carbon isotope discrimination in birch (Betula pendula Roth.) transplants were evaluated using seedlings grown with and without N fertiliser, and under two concentrations of atmospheric CO₂ (ambient and ambient+250 μmol mol^-1) in solar dome systems. N fertilisation decreased n-fatty acid chain length (18:0/16:0) and the ratios of α-linolenate (18:2)/linoleate (18:1), whereas elevated [CO₂] showed little effect on n-fatty acid chain length, but decreased the unsaturation (18:2+18:1)/18:0. Both N fertilisation and elevated [CO₂] increased the quantity of leaf wax n-alkanes, whilst reducing that of n-alkanols by 20–50%, but had no simple response in fatty acid concentrations. ¹³C enrichment by 1–2.5‰ under N fertilisation was observed, and can be attributed to both reduced leaf conductance and increased photosynthetic consumption of CO₂. Individual n-alkyl lipids of different chain length show consistent pattern of δ¹³C values within each homologue, but are in general 5–8‰ more depleted in ¹³C than the bulk tissues. Niether nitrogen fertilisation and elevated CO₂ influenced the relationship between carbon isotope discrimination of the bulk tissue and the individual lipids. This revised version was published online in June 2006 with corrections to the Cover Date.     

Influence of Temperature and Seed Ripening on the in-vivo Incorporation of CO(2) into the Lipids of Oat Grains (Avena sativa L.)

To elucidate the influence of growth temperature and of stage of maturity on lipid synthesis in seeds, oat plants (Avena sativa nuda L., variety NOS) were fed with ¹⁴CO₂ at different stages after flowering, and the ¹⁴C-incorporation into the grain lipids was determined at 2, 24, and 48 hours after the end of ¹⁴CO₂-application. By changing growth temperature from 12 C to 28 C after the application of ¹⁴CO₂ to intact plants, a higher ¹⁴C-labeling of saturated fatty acids was found at the higher temperature. At 28 C, palmitic and stearic acids contained 23% and 9% respectively of total fatty acid-¹⁴C shortly after the ¹⁴CO₂-application, whereas at 12 C the corresponding values were 19% and 4%, respectively. Within 2 days ¹⁴C-activity of saturated fatty acids decreased at both temperatures, but to a lesser degree at 28 C. The higher ¹⁴C-labeling of saturated fatty acids and its lower decrease within 2 days at 28 C clearly show a direct influence of temperature on fatty acid biosynthesis in oat grains.     

The effects of host carbon dioxide, nitrogen and water supply on the infection of wheat by powdery mildew and aphids

In two experiments, winter wheat (Triticum aestivum cv. Cerco) was grown in 350 (ambient) and 700 μmol mol^-1 (elevated) atmospheric CO₂ concentrations. In the first experiment, plants were grown at five levels of nitrogen fertilization, and in the second experiment, plants were grown at three levels of water supply. All plants were infected with powdery mildew, caused by the fungus Erysiphe graminis. Plants grown in elevated atmospheric CO₂ concentrations had significantly reduced % shoot nitrogen contents and significantly increased % shoot water contents. At elevated atmospheric CO₂ concentrations, where plant nitrogen content was significantly reduced, the severity of mildew infection was significantly reduced, and where host water content was significantly increased, the severity of mildew infection was significantly increased. In a moderate water supply treatment, the plants grown in elevated atmospheric CO₂ concentrations had significantly reduced nitrogen contents (9·9%) and significantly increased water content (4%), the amount of mildew infection was unchanged. The severity of mildew infection appeared to be more sensitive to host water content than to host nitrogen content.     

Allocation and Turnover of Photosynthetically Assimilated CO(2) in Leaves of Glycine max L. Clark

The allocation and turnover of photosynthetically assimilated ¹⁴CO₂ in lipid and protein fractions of soybean (Glycine max L. Clark) leaves and stem materials was measured. In whole plant labeling experiments, allocation of photosynthate from a pulse of ¹⁴CO₂ into polymeric compounds was: 25% to proteins in 4 days, 20% to metabolically inert cell wall products in 1 to 2 days, 10% to lipids in 4 days, and 4% to starch in 1 day. The amount of ¹⁴C labeled photosynthate that an actively growing leaf (leaf 4) used for its own lipid synthesis immediately following pulse labeling was about 25%. The ¹⁴C of labeled proteins turned over with half-lives of 3.8, 3.3, and 4.1 days in leaves 1, 2, and 3, respectively; and turnover of ¹⁴C in total shoot protein proceeded with a half-life of 5.2 days. Three kinetic ¹⁴C turnover patterns were observed in lipids: a rapid turnover fraction (within a day), an intermediate fraction (half-life about 5 days), and a slow turnover fraction. These results are discussed in terms of previously published accounts of translocation, carbon budgets, carbon use, and turnover in starch, lipid, protein, and cell wall materials of various plants including soybeans.     

Endogenous substrate for energy metabolism and ultrastructural correlates in spermatozoa of the sea urchin Diadema setosum

Energy metabolism in spermatozoa of the sea urchin Diadema setosum of the order Diadematoida was examined. The spermatozoa contained not only several kinds of phospholipids and cholesterol, but also triglyceride (TG). Glycogen and glucose were present at extremely low levels. Following dilution of dry sperm and incubation in seawater, the TG content decreased rapidly. Other lipids, however, remained at constant levels, except for a slight increase in the level of free fatty acid. High lipase activity was demonstrated in the spermatozoa. ¹⁴C-labeled fatty acid was oxidized to ¹⁴CO₂. Ultrastructural study also showed that lipid globules were present at the bottom of the midpiece. After incubation in seawater, morphological changes in the lipid globules were observed and some vacuoles appeared. Thus, the results obtained strongly suggest that D. setosum spermatozoa obtain energy through oxidation of fatty acid from TG stored in the lipid globules at the midpieces. © 1995 Wiley-Liss, Inc.     

The effect of ammonium and nitrate on CO2 assimilation,RuBP and PEP carboxylase activity and dry matter production in wheat

Photosynthetic¹⁴CO₂ assimilation, ribulose 1, 5-bisphosphate carboxylase (RuBPC), phosphoenol pyruvate carboxylase (PEPC) and dry matter (DM) production were examined in wheat under varying levels and forms of nitrogen.¹⁴CO₂ assimilation increased gradually after germination reaching a peak value at anthesis, followed by a sharp decline. A similar pattern was observed for both the carboxylases, RuBPC and PEPC activities. Increase in nitrogen levels, in general, brought about a significant increase over the control (zero-nitrogen) in¹⁴CO₂ assimilation, RuBPC, PEPC activities and DM production. There were no significant differences in RuBPC activity and¹⁴CO₂ assimilation with respect to the forms of nitrogen. Significantly higher PEPC activity and DM was observed in plants supplied with nitrate-nitrogen (NO₃-N), as compared to those supplied with ammonium-nitrogen (NH₄-N). The significance of PEPC activity in C₃ photosynthesis is discussed in relation to DM distribution.     

Assessment of <Emphasis Type="Italic">Nannochloropsis gaditana</Emphasis> growth and lipid accumulation with increased inorganic carbon delivery

Algal biomass refineries for sustainable transportation fuels, in particular biodiesel, will benefit from algal strain enhancements to improve biomass and lipid productivity. Specifically, the supply of inorganic carbon to microalgal cultures represents an area of great interest due to the potential for improved growth of microalgae and the possibility for incorporation with CO₂ mitigation processes. Combinations of bicarbonate (HCO₃^?) salt addition and application of CO₂ to control pH have shown compelling increases in growth rate and lipid productivity of fresh water algae. Here, focus was placed on the marine organism, Nannochloropsis gaditana, to investigate growth and lipid accumulation under various strategies of enhanced inorganic carbon supply. Three gas application strategies were investigated: continuous sparging of atmospheric air, continuous sparging of 5% CO₂ during light hours until nitrogen depletion, and continuous sparging of atmospheric air supplemented with 5% CO₂ for pH control between 8.0 and 8.3. These gas sparging schemes were combined with addition of low concentrations (5 mM) of sodium bicarbonate at inoculation and high concentration (50 mM) of sodium bicarbonate amendments just prior to nitrogen depletion. The optimum scenario observed for growth of N. gaditana under these inorganic carbon conditions was controlling pH with 5% CO₂ on demand, which increased both growth rate and lipid accumulation. Fatty acid methyl esters were primarily comprised of C16:0 (palmitic) and C16:1 (palmitoleic) aliphatic chains. Additionally, the use of high concentration (50 mM) of bicarbonate amendments further improved lipid content (up to 48.6%) under nitrogen deplete conditions when paired with pH-controlled strategies.     

Revealing the polar lipidome,pigment profiles,and antioxidant activity of the giant unicellular green alga,Acetabularia acetabulum

Marine algae are one of the most important sources of high-value compounds such as polar lipids, omega-3 fatty acids, photosynthetic pigments, or secondary metabolites with interesting features for different niche markets. Acetabularia acetabulum is a macroscopic green single-celled alga, with a single nucleus hosted in the rhizoid. This alga is one of the most studied dasycladalean species and represents an important model system in cell biology studies. However, its lipidome and pigment profile have been overlooked. Total lipid extracts were analyzed using hydrophilic interaction liquid chromatography-high resolution mass spectrometry (HILIC-HRMS), tandem mass spectrometry (MS/MS), and high-performance liquid chromatography (HPLC). The antioxidant capacity of lipid extracts was tested using DPPH and ABTS assays. Lipidomics identified 16 polar lipid classes, corresponding to glycolipids, betaine lipids, phospholipids, and sphingolipids, with a total of 191 lipid species, some of them recognized by their bioactivities. The most abundant polar lipids were glycolipids. Lipid classes less studied in algae were identified, such as diacylglyceryl-carboxyhydroxymethylcholine (DGCC) or hexosylceramide (HexCer). The pigment profile of A. acetabulum comprised carotenoids (17.19%), namely cis-neoxanthin, violaxanthin, lutein and β,β-carotene, and chlorophylls a and b (82.81%). A. acetabulum lipid extracts showed high antioxidant activity promoting a 50% inhibition (IC₅₀) with concentrations of 57.91 ± 1.20 μg · mL⁻¹ (438.18 ± 8.95 μmol Trolox · g⁻¹ lipid) in DPPH and 20.55 ± 0.60 μg · mL⁻¹ in ABTS assays (918.56 ± 27.55 μmol Trolox · g⁻¹ lipid). This study demonstrates the potential of A. acetabulum as a source of natural bioactive molecules and antioxidant compounds.