Lipid Extracts Research Articles

Innovative Strategies for Microalgae-Based Bioproduct Extraction in Biorefineries: Current Trends and Future Solutions Integrating Wastewater Treatment

Recently, microalgae have emerged as a promising feedstock for biorefineries, offering significant potential for producing high-value bio-based products in areas such as biofuels, nutraceuticals, and environmental management. This study, therefore, undertook an in-depth bibliometric review of 535 articles out of 736 publications published between 2010 and 2024 and sourced from the Scopus database. With the use of the VOS-viewer software, this work identified the major trends within significant research areas in terms of focus and global collaboration networks that pertain to microalgae-based bioproducts. Also, it explored cutting-edge techniques for bioproduct extraction and processing that are both efficient and eco-friendly. This analysis also showed a remarkable growth in output, with peaks in the year 2022, reflecting an interest in renewable energy and methods of sustainable production. The main keywords identified deal with subject areas such as energy, environmental science, and chemical engineering. The dominant technologies referred to dealing with lipid extraction, bio-crude production, and nutrient recycling. While addressing cost, scale-up, and environmental concerns, there is still a need to improve extraction techniques like ultrasonic treatment, supercritical fluid treatment, and enzymatic treatment. Other emerging areas of research include genetic engineering and integrated biorefinery models, which are expected to provide a roadmap for future advancements in the field. The challenges innate in meeting this through innovation and optimization will be the key to realizing the full potential of microalgae to contribute to the circular bioeconomy.

Immunomodulatory effect of shrimp by-products in diets for Nile tilapia (Oreochromis niloticus)

Aquaculture plays a critical role in food security, with Nile tilapia (Oreochromis niloticus) being one of the most widely farmed species due to its resilience and adaptability. However, the reliance on traditional feed ingredients poses sustainability challenges. This study aimed to investigate the immunomodulatory effects of incorporating shrimp cephalothorax lipid extract (SCLE) and shrimp cephalothorax meal (SCM) in Nile tilapia diets as sustainable feed alternatives. Two experiments were conducted using diets with varying levels of SCLE (0.4%, 0.8%, 1.2%, and 1.6%) and SCM (5%, 10%, 15%, and 20%). A total of 200 healthy, uniformly sized Nile tilapia fingerlings were selected for two trials with average weights of 4.38±0.13 g and 3.24±0.07 g, respectively. Fish were distributed across 20 tanks and fed ad libitum for 45 days. Hematological parameters were analyzed, revealing that diets with SCLE significantly increased leukocyte, thrombocyte, and hematocrit levels, particularly at 1.6% inclusion. SCM inclusion also led to higher leukocyte counts, especially at 20%. These findings suggest that SCLE and SCM positively impact the innate immune system of Nile tilapia, enhancing their ability to resist pathogens. Additionally, the use of shrimp by-products in aquafeeds presents a viable strategy for reducing environmental waste and promoting more sustainable practices in aquaculture.

Lipid extract from Black Soldier Fly larvae: A high value excipient for solid lipid nanoparticles tailored to tackle atopic dermatitis

Atopic dermatitis (AD) is a chronic inflammatory skin disorder with a complex pathogenesis involving epidermal barrier dysfunction and aberrant lipid composition, particularly ceramides and fatty acids (FA). Conventional management options, such as topical glucocorticoids (GC), often lead to adverse effects upon prolonged usage, prompting the exploration of alternative therapeutic strategies. The lipid extract from Black Soldier Fly larvae (BSFL) biomass, holding a rich blend of FA, holds substantial potential as a novel ingredient to tackle skin barrier impairment. This study aimed to achieve proof-of-concept validation of innovative nanotechnology-based formulations tailored to enhance the topical management of AD. Specifically, solid lipid nanoparticles (SLNs) with BSFL lipid extract were developed to perform both as a carrier for dexamethasone (DEX), a representative GC, and as skin barrier repair adjuvants. Through systematic optimization using Box-Behnken Design, BSFL lipid extract-based SLNs demonstrated favorable physicochemical properties for topical application and satisfactory stability over 2 months. Notably, these SLNs exhibited favorable drug release kinetics, delivering the total DEX payload within a therapeutically relevant timeframe. Furthermore, these nanocarriers showed the ability to permeate human keratinocytes without pronounced toxicity, suggesting their potential utility in enhancing drug delivery and cellular uptake. Overall, these findings suggest that BSFL lipid extract is a promising natural and sustainable ingredient for the development of nanotechnology-driven approaches to AD management, offering a potential avenue for addressing the unmet needs in this challenging dermatologic condition.

Four-Dimensional Lipidomic Analysis Using Comprehensive Online UHPLC × UHPSFC/Tandem Mass Spectrometry.

Multidimensional chromatography offers enhanced chromatographic resolution and peak capacity, which are crucial for analyzing complex samples. This study presents a novel comprehensive online multidimensional chromatography method for the lipidomic analysis of biological samples, combining lipid class and lipid species separation approaches. The method combines optimized reversed-phase ultrahigh-performance liquid chromatography (RP-UHPLC) in the first dimension, utilizing a 150 mm long C18 column, with ultrahigh-performance supercritical fluid chromatography (UHPSFC) in the second dimension, using a 10 mm long silica column, both with sub-2 μm particles. A key advantage of employing UHPSFC in the second dimension is its ability to perform ultrafast analysis using gradient elution with a sampling time of 0.55 min. This approach offers a significant increase in the peak capacity. Compared to our routinely used 1D methods, the peak capacity of the 4D system is 10 times higher than RP-UHPLC and 18 times higher than UHPSFC. The entire chromatographic system is coupled with a high-resolution quadrupole-time-of-flight (QTOF) mass analyzer using electrospray ionization (ESI) in both full-scan and tandem mass spectrometry (MS/MS) and with positive- and negative-ion polarities, enabling the detailed characterization of the lipidome. The confident identification of lipid species is achieved through characteristic ions in both polarity modes, information from MS elevated energy (MSE) and fast data-dependent analysis scans, and mass accuracy below 5 ppm. This analytical method has been used to characterize the lipidomic profile of the total lipid extract from human plasma, which has led to the identification of 298 lipid species from 16 lipid subclasses.

Halobacillus rhizosphaerae sp. nov., a moderately halophilic bacterium with protease activities isolated from the rhizosphere soil of the mangrove Acanthus ebracteatus.

A Gram-positive, moderately halophilic, rod-shaped and facultatively anaerobic strain T66T, was isolated from the rhizosphere soil of mangrove Acanthus ebracteatus in Guangxi, China. Strain T66T was observed to grow at 15-40℃ (optimum 30℃), pH 5-8 (optimum 6-7) and with 2-20% (w/v) NaCl (optimum 6%). The phylogenetic tree of the 16S rRNA gene sequences depicted a cluster of strain T66T to be closely related to Halobacillus litoralis SL-4T (98.72%), Halobacillus dabanensis D-8T (98.70%) and Halobacillus campisalis ASL-17T (98.66%). The phylogenetic analysis based on the 16S rRNA gene sequence showed that strain T66T belonged to the genus Halobacillus and formed a separate branch. The digital DNA-DNA hybridisation and average nucleotide identify values between strain T66T and its related species were 17.80-19.80% and 70.78-73.22%, respectively, which were lower than the threshold recommended for species delineation. The genomic DNA G + C content was 40.9%. The predominant isoprenoid quinone was MK-7, the cell-wall peptidoglycan contained meso-diaminopimelic acid, and the major fatty acids that accounted for more than 10.0% were anteiso-C15:0 (68.4%) and anteiso-C17:0 (13.4%). Phosphatidylglycerol, diphosphatidylglycerol, three unidentified phospholipids and an unidentified glycolipid were found in the polar lipid extraction. Strain T66T could hydrolyse casein and contains several genes (e. g. vanY, vpr, pbpG and elpC) involved in protease. Therefore, strain T66T is salt-tolerant and produces protease, and it may have development and utilisation value in flavouring agents and food curing. Based on phenotypic, chemotaxonomic data and genotypic characteristics, strain T66T represents a novel species of the genus Halobacillus, for which the name Halobacillus rhizosphaerae sp. nov. is proposed. The type strain is T66T (= JCM 36534T = MCCC 1K08701T).

Extraction of high-quality Antarctic krill (Euphausia Superba) oil using low-temperature continuous phase-transition extraction equipment.

The aim of this study was to explore a processing method for efficient extraction of high-quality krill oil (KO) using a low-temperature continuous phase-transition extraction equipment (LCPE). The efficiency of lipid extraction and quality of KO and defatted krill meal (DKM) by LCPE were compared with those of supercritical CO2 and n-hexane extraction. Results showed that compared to other methods, extraction using LCPE had the highest lipid yield (21.72±0.34%), bioactive substances, and dimethyl sulfide (3.12±0.09mg/kg), the lowest oxidative deterioration. Moreover, compared to other methods, DKM extracted by LCPE had the lowest fat (<2%), the highest protein (>60%), and the best oxidative stability. These benefits would ensure easier transportation and better long-term storage, allowing for its application on distant-ocean fishing vessels. Therefore, LCPE is a method that allows for efficient extraction of high-quality KO.

Preparation of functional supplement powder using nanoliposome-containing marine bioactive compounds.

The demand for marine bioactive compounds as therapeutic agents in supplements or functional foods has increased. However, their instability, bitter taste, and potential degradation during digestion have hindered their widespread use. To overcome these problems, a functional supplement powder was produced using the encapsulation technique of nanoliposomes containing shrimp lipid extract, fish oil (FO), and fish protein hydrolysate. Chitosan and whey protein concentrate (WPC) were used to coat the nanoliposomes in mono/bilayer and composite forms, followed by freeze-drying for 72h. The physicochemical characteristics, nutritional, in vitro release, and sensory evaluation were investigated. The WPC-monolayer treatment exhibited the highest solubility (28.83mg/100g), encapsulation efficiency (97.67%), and polyunsaturated fatty acids (PUFAs). Although the mono/bilayer treatments of whey protein showed lower docosahexaenoic acid and eicosapentaenoic acid than FO, they presented a favorable amino acid profile. Compared to acidic stomach conditions, the release in the intestine was higher. Incorporating 1.5g of the supplement powder per 100g of milk can meet an individual's daily nutritional needs for essential amino acids and PUFAs. Therefore, encapsulating marine bioactive compounds in liposomal carriers could be a beneficial approach to their direct use as a nutritious powder.

Tandem Mass Spectrometry in Untargeted Lipidomics: A Case Study of Peripheral Blood Mononuclear Cells.

Peripheral blood mononuclear cells (PBMCs), including lymphocytes, are important components of the human immune system. These cells contain a diverse array of lipids, primarily glycerophospholipids (GPs) and sphingolipids (SPs), which play essential roles in cellular structure, signaling, and programmed cell death. This study presents a detailed analysis of GP and SP profiles in human PBMC samples using tandem mass spectrometry (MS/MS). Hydrophilic interaction liquid chromatography (HILIC) and electrospray ionization (ESI) coupled with linear ion-trap MS/MS were employed to investigate the diagnostic fragmentation patterns that aided in determining regiochemistry in complex lipid extracts. Specifically, the study explored the fragmentation patterns of various lipid species, including phosphatidylcholines (PCs), phosphatidylethanolamines (PEs), their plasmalogen and lyso forms, phosphatidylserines (PSs), phosphatidylinositols (PIs), phosphatidylglycerols (PGs), sphingomyelins (SMs), and dihexosylceramides (Hex2Cer). Our comprehensive analysis led to the characterization of over 200 distinct lipid species, significantly expanding our understanding of PBMC lipidome complexity. A freely available spreadsheet tool for simulating MS/MS spectra of GPs is provided, enhancing the accessibility and reproducibility of this research. This study advances our knowledge of PBMC lipidomes and establishes a robust analytical framework for future investigations in lipidomics.

A simultaneous analysis strategy of glycerophospholipids and lipid mediators based on secondary extraction scheme.

Lipid peroxidation plays an important role in physiological and pathophysiological conditions; it occurs mainly in the vicinity of the membrane. Glycerophospholipids are indispensable for normal structure of membranes. Lipid mediators are final products of lipid peroxidation. Glycerophospholipids as a source of lipid mediators are closely related with lipid mediators in lipid peroxidation process. This study developed a strategy for simultaneous analysis of glycerophospholipids and lipid mediators in a sample based on a secondary extraction scheme. Due to differences in physicochemical properties of glycerophospholipids and lipid mediators, we used different solvents and methods to extract glycerophospholipids and lipid mediators based on a sample. In addition, we compared three methods of extracting glycerophospholipids to select the best extraction method. In this study, a UPLC-MRM absolute quantification strategy for three deuterated internal standards of lipid mediator was established. The calibration range of all standards is linear, and the correlation coefficients are greater than 0.999. Quantitative range, precision, and accuracy of all analytes-based analysis method meet requirements of method validation. And the accuracy and precision of this method for glycerophospholipids meet the requirements of method verification. It is satisfactory to apply this method in the analysis of the changes of enzymes in lipid peroxidation during the treatment of asthma with dexamethasone. The quantitative results of phospholipids and lipid mediators in mouse lung tissue were obtained by this method, indicating that dexamethasone may inhibit the activity of phospholipase As enzyme and thus slow down the lipid peroxidation process. This work may be of great significance for exploring the changes of enzymes in lipid peroxidation metabolism.

Advances in utilizing reverse micelles to investigate membrane proteins.

Reverse micelles (RMs) have emerged as useful tools for the study of membrane associated proteins. With a nanoscale water core surrounded by surfactant and solubilized in a non-polar solvent, RMs stand apart as a unique membrane model. While RMs have been utilized as tools to investigate the physical properties of membranes and their associated water, RMs also effectively house membrane associated proteins for a variety of studies. High-resolution protein NMR revealed a need for development of improved RM formulations, which greatly enhanced the use of RMs for aqueous proteins. Protein-optimized RM formulations enabled encapsulation of challenging membrane associated protein types, including lipidated proteins, transmembrane proteins, and peripheral membrane proteins. Improvements in biological accuracy of RMs using phospholipid-based surfactants has advanced their utility as a membrane mimetic even further, better matching the chemistry of the most common cellular membrane lipids. Natural lipid extracts may also be used to construct RMs and house proteins, resulting in a membrane model that better represents the complexity of biological membranes. Recent applications in high-resolution investigations of protein-membrane interactions and inhibitor design of membrane associated proteins have demonstrated the usefulness of these systems in addressing this difficult category of protein. Further developments of RMs as membrane models will enhance the breadth of investigations facilitated by these systems and will enhance their use in biophysical, structural, and drug discovery pursuits of membrane associated proteins. In this review, we present the development of RMs as membrane models and their application to structural and biophysical study of membrane proteins.

Assessing the effect of minimally invasive lipid extraction on parchment integrity by artificial ageing and integrated analytical techniques

To assess the short and long-term effect of a newly developed minimally invasive lipid extraction method on parchment, sacrificial pieces of parchments were subjected to artificial ageing and investigated using various analytical methods. Lipids were extracted using our novel vacuum-aided extraction method and characterised by high-temperature gas chromatography (HTGC-FID). Lipids were identified as arising from degraded animal fats. The physical, molecular, and mechanical properties of the parchment samples before/after lipid extraction, and before/after ageing were assessed using scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR) and pure shear single notch fracture testing. SEM imaging allowed for an assessment of potential structural changes of the collagen fibres while FTIR was used to investigate the possible molecular changes indicated by changes in amide I and II bands. Mechanical tests were used to record the changes in brittleness and stiffness occurring in the materials through lipid extraction and ageing. The multimodal investigation did not highlight measurable changes in the structural, molecular, and mechanical properties of the lipid-extracted parchment, thus indicating the suitability for the minimally invasive lipid extraction method to be applied to historical parchments.

Impact of lipids removal on the color, cooking characteristics, textural properties, and UHPLC‐QToF‐IMS‐based metabolites of Indian brown rice using supercritical carbon dioxide

AbstractBackground and ObjectivesThe study investigated the effect of lipid extraction by using the supercritical carbon dioxide (sCO2) process from brown rice (BR) of different Indian rice varieties (PB386, PB3, PB1121, PB1637, PR122, PR123, PR129, and PR113). BR was evaluated for color, pasting, cooking, and textural properties. UHPLC‐QToF‐IMS analysis was also carried out to make a comparison in fatty, phenolic, and amino acid profiles between BR of different varieties.FindingsDefatted BR (DBR) from all varieties exhibited increased L* (Lightness) while lower a* (redness to greenness) and b* (yellowness to blueness) than BR. Cooking time and hardness decreased, and water uptake increased in both types of DBR. Defatting of BR increased peak viscosity while it decreased pasting temperature in all the varieties. Fatty acids and phenolic acids compounds decreased while minor increases in amino acids were observed on defatting in all the varieties.ConclusionTherefore, sCO2 extraction was observed as a promising alternative to conventional methods like polishing to enhance the organoleptic and nutritional quality of the rice.

Enhanced Lipidomics Analysis of Breast Cancer Cells Using Three-phase Liquid Extraction and Ultra High-performance Liquid Chromatography Coupled With Quadrupole Time-of-Flight Tandem Mass Spectrometry.

Lipid extraction of complex biological samples is essential for high-quality data in liquid chromatography-mass spectrometry (LC-MS)-based lipidomics. This study introduces a three-phase liquid extraction (3PLE)-ultra-high-performance LC coupled with quadrupole time-of-flight tandem MS method. This method was successfully applied to lipidomics analysis of breast cancer cells, including highly metastatic MDA-MB-231 and slightly metastatic MCF7 cells. The 3PLE method employed an n-hexane/methyl tert-butyl ether/acetonitrile/water solvent system that formed one aqueous and two organic phases. Neutral and polar lipids were enriched in the upper and middle organic phases, respectively, and combined for detection, thereby reducing analysis time. Compared with the Bligh and Dyer method, 3PLE achieved higher sensitivity and detected more features, with over a 50% increase in the relative abundance of nearly 50% of the differential lipids. In total, 21 differential lipids were identified in the MDA-MB-231 group and 22 in the MCF7 group compared to normal breast epithelial cells (MCF10A). Pathway analysis suggested that lipid changes in breast cancer cells were associated with glycerophospholipid metabolism, arachidonic acid metabolism, sphingolipid metabolism, and linoleic acid metabolism. The study presents a highly efficient lipidomics method, providing a scientific foundation for understanding breast cancer pathogenesis and aiding in diagnosis.

Optimization of the marine microalgae Nannochloropsis oculata harvesting by flocculation: Effects on biomass quality and residual medium reuse for a new cycle

ABSTRACT Flocculation using natural plant-based biopolymers from Moringa oleifera seeds and Acacia mearnsii flocculant as Tanfloc® (TSG) has emerged as an efficient strategy for microalgae biomass harvesting. This study optimized the recovery process of Nannochloropsis oculata by varying flocculant concentration, sedimentation time, and culture pH. Results revealed that 1.2 mg.L−1 of TSG at pH 8.9 achieved optimal conditions, although TSG proved effective across different pH ranges. Alkaline flocculation (ALK) also enhanced microalgae harvesting, yielding a high harvesting efficiency (>96%) within 30 minutes of sedimentation. Both methods achieved a concentration factor exceeding 20. However, the use of ALK resulted in reduced lipid and carbohydrate content compared to the control condition. Carotenoid levels showed no significant difference. TSG influenced lipid extraction but not fatty acid quality or carbohydrate extraction. Importantly, the residual medium from TSG flocculation could sustain subsequent cultivation cycles without nutrient supplementation, presenting a cost-effective solution for microalgae cultivation and harvesting.

Discovering oxidized polar lipids in microalgae lipidome using liquid chromatography mass spectrometry approaches

Microalgae are rich in polar lipids, such as glycolipids, phospholipids and betaine lipids esterified with omega-3 polyunsaturated fatty acids (PUFA), which are prone to oxidation. Under stress conditions, the redox balance in microalgae is altered, leading to an abnormal production of reactive oxygen species (ROS) that can affect surrounding lipids. While few oxidized polar lipids have been described to play important roles in mammals and possess interesting bioactive properties, their occurrence in microalgae is poorly described, hindering their exploitation as novel bioactive compounds. To enhance our understanding of these lipids, we conducted a targeted analysis of oxidized polar lipids in lipid extracts obtained from five microalgae species: Chlorella vulgaris, Chlorococcum amblystomatis, Scendesmus obliquus, Nanochloropsis oceanica and Phaeodactylum ticornutum, using reverse-phase liquid chromatography mass spectrometry (RP-LC-MS). A detailed analysis of the LC-MS data identified 150 oxidized polar lipid species across different classes of phospholipids, glycolipids and betaine lipids in the five microalgae species. These modified oxidized lipids featured oxygenated species with 1–3 additional oxygen atoms in the fatty acyl chains. The predominant oxidized fatty acids esterified to these lipids were omega-3 eicosapentaenoic acid (EPA, 20:5 n-3) and α-linonelic acid (ALA, 18:3 n-3). Notably, most oxidized lipid species were identified in diacylglyceryl-N,N,N-trimethylhomoserine (DGTS) in C. amblystomatis, S. obliquus and N. oceanica, monogalactosyldiacylglycerol (MGDG) in P. tricornutum, and phosphatidylethanolamine (PE) in C. vulgaris. Furthermore, distinct fragmentation patterns across lipid classes allowed the unequivocal identification of oxidized polar lipids. These findings reveal a diverse array of oxidized polar lipids in microalgae, predominantly enriched with oxidized omega-3 PUFA, highlighting microalgae as a natural source of oxidized polar lipids that may serve as a natural reservoir of bioactive omega-3 oxylipins.

Evaluation of the pharmacological efficiency of the lipid extract from the tunic of the marine hydrobiont Halocynthia aurantium (Pallas, 1774)

It was studied effect of the lipid extract isolated from the tunic of the marine hydrobiont Halocynthia aurantium. It was evaluated its administration during hypothermia, hyperthermia, muscle load and the introduction of hexenal as well as its embryotoxic and teratogenic effects The impact of stress (vertical fixation of rats by the dorsal neck fold) was accompanied by an increase in plasma levels of total lipids, total cholesterol, cholesterol/phospholipid ratios and a decrease in total phospholipids, as well as by a change in the quantitative characteristics of classes of neutral and phospholipid. It was carried out a correction of the developed changes by a lipid extract of ascidia and a commercial reference preparation “Omega-3”. The lipid extract of H. aurantium showed a higher efficiency in restoring the lipid composition of the blood plasma under stress impact compared to the preparation “Omega-3” due to a wider range of neutral and phospholipid classes, polyunsaturated fatty acids of the n-3 and n-6 families. The tunica of ascidian can be used as a raw material for obtaining preparations with stress-protector and lipid-correcting properties.

Techno-economic analysis of bioplastic and biofuel production from a high-ash microalgae biofilm cultivated in effluent from a municipal anaerobic digester

Rotating Algae Biofilm Reactors (RABRs) are a promising technology for efficient treatment of wastewater and production of algae-based bioproducts. However, RABR-grown algae can contain a high content of ash (30–60 wt%, dry basis), which influences the technical and economic feasibility of bioproduct conversion processes. In this report, experimental studies and economic analysis were conducted to compare different processes for bioproduct conversion of a high-ash microalgae biofilm grown using a RABR treating 0.6 million gallons per day of anaerobic digestion centrate at the Central Valley Water Reclamation Facility in Salt Lake City, UT. Process and economic models were developed and compared for three conversion processes: 1) the production of bioplastics, 2) the production of bioplastics with a lipid-extraction pretreatment, and 3) the production of biocrude via hydrothermal liquefaction. Techno-economic analysis was performed for each conversion process, including three cases for algae productivity: 231, 391, and 577 metric tons per year (dry basis). The calculated value for the minimum plastic selling price (MPSP) of bioplastics produced from algae ranges from $4050 to $3520 per metric ton based on the baseline and final productivity cases of the RABR, respectively. The extraction of lipids in addition to bioplastic production results in an MPSP of $4570 to $4000 per metric ton for the same productivity cases. The relatively small production scale and complex processing for hydrothermal liquefaction results in a minimum fuel selling price of the biocrude of $5.32 per gallon of gasoline equivalent. The conversion process for bioplastic production from whole algae has the highest income:expense ratio and the most cost-competitive pricing of the three modeled processes.

Characterization of Extracellular Vesicles by Sulfophosphovanillin Colorimetric Assay and Raman Spectroscopy.

Detailed characterization of extracellular vesicles (EVs) is crucial for their application in medical diagnostics. However, the complexity of their chemical composition and the heterogeneity of EV populations make their characterization challenging. Here we describe two analytical procedures that can help overcome this challenge. Small EVs were isolated from conditioned cell culture media using ultracentrifugation and characterized using nanoparticle tracking analysis (NTA) and transmission electron microscopy (TEM). Raman spectroscopy was used to assess the overall composition of the isolated samples and lipids extracted from them. Sulfophosphovanillin (SPV) colorimetric assay was used to quantify the contents of lipid. Six samples of EVs were characterized. The lipid contents measured using SPV assay was in reasonable agreement with the quantitative estimates based on the particle size and concentration measured using NTA. The most peaks observed in the Raman spectra could be attributed to either proteins or lipids, and their origins was confirmed by lipid extraction. The protein-to-lipid ratio was estimated based on the Raman spectra. The experiential procedures described in this study will help to overcome the challenge of quick and highly informative characterization of the EVs.

Environmental impact assessment in microalgal lipid production: carbon footprint and net emissions

This study focuses on analyzing the role of microalgae in mitigating climate change through CO2 capture and lipid production, which can be used in the development of energy products and commercially relevant products. The objective was to evaluate the net CO2 emissions in three lipid production scenarios from microalgae, in addition to analyzing the impact of various biomass pretreatment technologies before lipid extraction. For this purpose, only the emissions directly generated by energy consumption in the process and the amount of CO2 that can be captured by microalgae cultivation were considered. In all three scenarios, CO2 capture during biomass cultivation and emissions associated with maintaining the process in operation were evaluated. The results show that the emissions generated by energy consumption were 3.56 kg-CO2/kg-oil, 2.19 kg-CO2/kg-oil, and 2.36 kg-CO2/kg-oil in scenarios 1, 2, and 3, respectively, while the CO2 emissions captured in microalgae cultivation were three to four times higher, ultimately resulting in negative emissions in all scenarios. The efficiency of CO2 capture per kilogram of oil produced varies between scenarios, suggesting that the choice of technology and process conditions significantly influence the overall environmental impact. This analysis identifies areas of opportunity to improve microalgal biomass utilization processes, highlighting the stages of the process with the greatest impact on the carbon footprint and enabling the comparison of different technologies on the same basis.

Ultrasound-assisted extraction vs. microwave-assisted extraction for sustainable development goals: Selecting the ideal lipid extraction and fatty acid profile

The objective of this study was to compare the efficiency of ultrasound-assisted extraction (UAE) and microwave-assisted extraction (MAE) methods for extracting lipids from the green microalga Chlorococcum novae-angliae. This study specifically focused on the fatty acid profiles of the extracted lipids, using ethanol as the solvent and wet biomass as the starting material. Ultrasound-assisted extraction yielded a maximum of 0.026 ± 0.001 g lipid/g wet biomass at a biomass ratio of 1:25 for 2 min with a 1-second cycle at 180 W and 20 kHz, which was 21% higher than that of microwave-assisted extraction conducted at a ratio of 1:30 for 2 min at 300 W and 35 °C. Ultrasound-assisted extraction enhanced saturated fatty acids (SFAs), which were 1.5 times higher than to microwave-assisted extraction, while microwave-assisted extraction significantly increased polyunsaturated fatty acids (PUFAs) by 4.4 times. The findings suggest that ultrasound-assisted extraction is more suitable for applications requiring high SFA content, such as in the fuel industry, whereas microwave-assisted extraction is preferable for sectors focused on fatty acid quality, such as food and health. This comparative analysis contributes to the literature by highlighting the impact of extraction methods on fatty acid profiles and supports sustainable development goals (SDGs), particularly SDG 12, by promoting environmentally friendly extraction techniques.