Lipid Extraction Yield Research Articles

The impact of supercritical carbon dioxide processing on the aroma and physicochemical properties of soybean flour

Soybeans are rich in protein but have limited food applications due to their undesirable volatile compounds, negatively affecting their flavor and consumer acceptance. This study aimed to extract lipids and volatile compounds from soybean flour using supercritical carbon dioxide (SC-CO2) and investigate the impact of extraction conditions on the properties of soybean flour, including particle size distribution, composition, color, and rheological and textural qualities. Similar lipid extraction yields (∼20%) were obtained with SC-CO2 and conventional hexane extractions. The volatile compound concentration of the soybean flour was reduced after SC-CO2 extraction (0.63-1.00 µg/g) as compared to hexane extraction (1.44-1.68 µg/g). The results showed that SC-CO2-treated soybean flour showed smaller particle sizes (<250 µm, ∼70%), improved protein purity upon protein extraction, and brighter color as compared to hexane-extracted flour. Additionally, in comparison to untreated soybean flour, SEM images revealed a more disrupted and rough structure in defatted soybean flour. Overall, the presented SC-CO2 approach can improve the aroma of soybean flour while achieving similar lipid extraction yields with conventional hexane extraction, all without the use of toxic organic solvents.

Maximizing Lipid Extraction from Chlorella pyrenoidosa: A Study on the Effectiveness of Cell Disruption Techniques

Microalgae are one of the most eco-friendly and promising raw material sources for the production of biofuel. Proteins, carbohydrates, lipids and nucleic acid are the major components of algal biomass depending upon the species. The present study aimed to determine the lipid extraction and transesterification from Chlorella pyrenoidosa microalgae. Different methods and solvents are used for the disruption of the cell-wall and extraction of lipid content. The methodology involved ultrasonication, microwave digestion, Soxhlet extraction and autoclave while using different solvents as methanol, chloroform, hexane, dichloromethane and heptane. We compared various cell disruption methods to improve lipid extraction yields and the highest lipid extraction yields were obtained using Soxhlet method with hexane. The obtained lipid converted into fatty acid methyl esters (FAMEs) through transesterification process. The identification of fatty acid was compared by retention time and individual pattern of use from caprylic acid (C8:0) to lignoceric acid (C24:0) in form of methyl ester. The Soxhlet method using methanol and chloroform and FAME analysis showed a highest percentage of palmitic acid (C16:0) and lowest percentage of myristic acid (C14:1).

Unlocking functional lipid ingredients from algae by food-grade biosolvents and ultrasound-assisted extraction for nutritional applications

Algae are a sustainable source of healthy and functional lipids. The production of extracts suitable for food and nutraceutical industries requires food-grade solvents, which may have low lipid extraction yield and/or purity. This work aimed to assess the efficiency of biosolvents ethanol (E) and ethyl acetate (EA) in obtaining food-grade lipid ingredients from an algae blend, Fucus vesiculosus, Ulva sp., and Chlorella vulgaris, in comparison with the Folch method. Ultrasound (UAE) was assayed to enhance the biosolvent extraction. The results showed that the different extraction approaches can significantly influence the extraction yield, lipid purity, and lipid composition, including fatty acid (FA) content. EA and EA + UAE produced high lipid purity (>74%) extracts with high polyunsaturated FA (≤77.5%) and n-3 FA (≤74.4%) contents, despite the lower extraction yield. E + UAE may be used to obtain lipid-rich ingredients from algae blend (57%) and C. vulgaris (91%). All extracts showed anti-inflammatory and antioxidant properties. This study provides relevant information for the production of food-grade lipid ingredients from algae.

Tisochrysis lutea as a source of omega-3 polar lipids and fucoxanthin: extraction and characterization using green solvents and advanced techniques

The marine microalga Tisochrysis lutea is a potential and sustainable source of bioactive compounds such as carotenoids and omega-3 fatty acids. In the present work, the extraction of fucoxanthin and docosahexaenoic acid (DHA), the most abundant omega-3 fatty acid which constitutes polar lipids particularly in the brain, was studied using advanced extraction techniques with green and bio-based solvents compared to traditional extraction techniques with hazardous organic solvents. The experimental design to maximize the lipid extraction yield by ultrasound-assisted extraction (UAE) was developed, choosing as experimental factors the percentage of solvent (0, 50 and 100% of 2-methyl-tetrahydrofuran or 2-methyloxolane (2-me-THF) in ethanol), the extraction time (20, 30 and 40 min) and temperature (40, 50 and 60 ºC). The highest lipid extraction yields were obtained using ethanol as solvent. Nevertheless, the most interesting extracts based on their chemical composition were obtained when the presence of 2-me-THF in the extraction mixture was greater than that of ethanol. Through analytical techniques such as HPLC-ELSD/DAD and GC-MS as well as spectrophotometric techniques, the contents of polar lipids, fatty acids, total carotenoids and fucoxanthin were quantified. In addition, the antioxidant capacity of different selected extracts was studied, being once again the most interesting those extracted with different amounts of 2-me-THF due to its selectivity and enriched composition in high-added value bioactives, mainly fucoxanthin and DHA. Therefore, it is shown the importance of choosing an advanced extraction technique together with the use of green solvents not only to develop procedures that are in agreement with Green Chemistry but also to preserve its bioactivity.

High-Resolution Lipidomics Reveals Influence of Biomass and Pretreatment Process on the Composition of Extracted Algae Oils As Feedstock for Sustainable Aviation Fuels.

The increasing demand for sustainable aviation fuel (SAF) creates a need for innovative biomass and lipid sources with compositions that are compatible with refineries. Algae-derived oils present an opportunity to supply a process-compatible lipid feedstock at yields higher than those of conventional oilseed crops. With few documented reports on chemical composition, the process readiness remains elusive. We present data on extraction efficiency, yield, and purity of lipids from algae with and without the application of a low-concentration sulfuric acid pretreatment of the biomass. The pretreatment process increased the oil yield and positively impacted the quality of the extracted oils. Results from fatty acid and lipidomics analysis revealed that the low-lipid biomass sources extracted 70-80% of the available lipids, and the non-fatty acid co-extractants exceeded 40% of the extracted oils. For a high-lipid algae sample, derived from a genetically engineered strain, we show >90% extraction yield with >85% FAME purity. This work provides insights into the composition of algae-derived oils and quality metrics that are essential to determining the viability of lipid hydroprocessing to SAF.

Incomplete lipid extraction as a possible cause for underestimation of lipid oxidation in emulsions

AbstractLipid oxidation deteriorates the sensory and nutritional quality of food emulsions containing polyunsaturated fatty acids. Classically, different extraction solvents are used as a first step to measure lipid oxidation in emulsions. However, it is unclear how the applied extraction method influences the measured lipid oxidation values. In this work, we systematically examined the performance of common solvent mixtures such as chloroform, methanol, and hexane (or isooctane)–isopropanol on lipid extraction from emulsions stabilized with different emulsifiers (Tween 20 (T20), whey proteins, and pea proteins) and oxidation levels, and how this, in turn, affected the measured hydroperoxide concentrations. Chloroform–methanol was the most effective solvent (lipid yield &gt;93 wt.%). When using hexane–isopropanol, extraction yields were consistently high for T20‐ and pea protein‐based emulsions (&gt;60 wt.%), but in whey protein‐based emulsions, values as low as 26 wt.% were measured. In case of incomplete extraction, hydroperoxide concentrations measured by colorimetric methods need to be corrected for this effect. When using 1H NMR to assess lipid oxidation, the actual amount of extracted lipids is intrinsically taken into account. This highlights not only the importance of the extraction method in determining lipid oxidation in emulsions but also that of the actual analysis method.Practical application: This study highlights that the lipid extraction yield can vary depending not only on the emulsion composition (e.g., type of emulsifier) but also on the oxidative state of the emulsion and the extraction solvent used. If this is overlooked, errors can be made in the hydroperoxide determination. Although these effects can be corrected for, this is not standard procedure, which implies that awareness on this matter should be increased. It is also important to point out that depending on the solvent used, the different lipid classes (including various lipid oxidation products) may be extracted at different levels. Chloroform–methanol should be preferred for extraction of all lipid and lipid oxidation‐derived molecules, including aldehydes.

Lipid extraction of high‐moisture sour cherry (Prunus cerasus L.) stones by supercritical carbon dioxide

AbstractBACKGROUNDSour cherry (Prunus cerasus L.) stones are the major byproduct of the cherry industry and the efficient management of this biowaste can lead to achieving the food processing sustainability aimed at by the modern food industry. Despite its significant content of lipids, the valorization of cherry stone waste as feedstock for lipid extraction appears to be limited due to the high moisture content. This study explores the primary factors that affect the yield of lipid extraction using Soxhlet, Randall and supercritical carbon dioxide (scCO2) extraction methods, with a particular emphasis on yield optimization for green extraction technologies (scCO2).RESULTSThe investigation revealed an increased lipid extraction yield for scCO2 from 7.4 for dry crushed stones to 20.6 g per 100 g dry weight when the cherry kernels are separated. The high initial moisture content affected all three extraction methods, but mostly impacted the scCO2 extraction, resulting in the co‐extraction of an aqueous phase. Lipid and aqueous yield could be manipulated by time, temperature and pressure. However, no observable influence on the composition of fatty acid methyl esters was detected.CONCLUSIONNumerous approaches are shown to enhance the lipid yield from cherry stone waste, depending on the desired outcome. When dealing with wet samples, Randall extraction proves to be the most effective method. On the other hand, scCO2 extraction presents distinct advantages, such as the extraction of food‐grade lipids and the co‐extraction of a unique aqueous phase, which comes at the expense of a reduced lipid yield. © 2024 The Authors. Journal of Chemical Technology and Biotechnology published by John Wiley &amp; Sons Ltd on behalf of Society of Chemical Industry (SCI).

Extraction of neutral lipids and phospholipids from marine biomasses using subcritical and supercritical fluids

Supercritical carbon dioxide (scCO2) and subcritical dimethylether (DME) were used to extract lipids from partially to fully dry marine biomass - whole jack mackerel (WJM), Hoki frames and heads (HFH), and Greenshell mussel meat (GSM). scCO2 gave a lower extraction yield of total lipids from GSM (42%) compared to WFH and HFH (86 - 88% yield) due to the higher concentration of phospholipids present in GSM. DME gave a higher extraction yield of total lipids and phospholipids than scCO2 for all marine biomass types. Phospholipid yield from GSM using DME was dependent on moisture content of the feed marine biomass and decreased with decreasing moisture content. Our results suggested that phospholipid extraction yield can be optimised by partly drying biomass to 30 - 50% moisture prior to extraction. DME extracts contained good levels of omega-3 fatty acids with minimal hydrolytic phospholipid degradation, thus providing a potential processing technology option to recover them from marine biomass.

Unconventional Extraction Methods of Oleaginous Yeast Cell Pretreatment and Disruption

Extraction is one of the most commonly used methods for obtaining and purifying chemical compounds for commercial usage. The aim of this study was to evaluate the effect of unconventional permeabilization and cell disruption methods on the yield of lipid extraction from cells of the oleaginous yeast Yarrowia lipolytica. Batch cultures in a medium with molasses and waste post-frying oil were carried out. The biomass was subjected to pulsed electric field (PEF), high-pressure processing (HPP), ultrasounds (US), and several conventional processing techniques with chemical and mechanical agents (glass beads, acetone, Triton and Tween surfactants). The effectiveness of the applied methods, either on cell permeabilization or cell disruption, was investigated by analyzing the oil and total protein extraction yield and oil leaching efficiency, as well as by using microscope images. The PEF and US treatments proved to be effective permeabilization methods as a step of sample pretreatment for extraction. These unconventional physical methods could efficiently increase intracellular lipid extraction yield in solvent applications.

An integrated approach for the extraction of lipids from marine macroalgae consortium using RSM optimization and thermo-kinetic analysis

This work presents an integrated approach for the extraction of lipids from marine macroalgae using RSM optimization and thermo-kinetic analysis. The lipids were extracted from marine macroalgal biomass using a Soxhlet extractor. The Soxhlet extraction parameters, including temperature (60–80 °C), solvent-to-algae ratio (3:1–7:1), algal particle size (0.05–0.25 mm), and extraction time (60–180 min), were optimized using RSM to achieve the maximum possible lipid extraction yield from marine macroalgae. The highest lipid extraction yield of 12.76% was obtained using the optimized conditions, which included an extraction temperature of 72 °C, a solvent-to-algae ratio of 5:1, an algal particle size of 0.16 mm, and an extraction time of 134 min. The kinetic analysis revealed an activation energy of 52.79 kJ mol−1 for the Soxhlet extraction process. The thermodynamic analysis of the Soxhlet extraction process demonstrated the following results: ΔH = 49.98 kJ mol−1, ΔS = −128.24 J K−1 mol−1, and ΔG = 93.98 kJ mol−1. The GC-MS analysis confirmed that the extracted algal lipids exhibited a composition of 14.20% palmitic acid, 4.89% stearic acid, and 76.97% oleic acid. The physiochemical analysis ensured that the extracted algal lipids possess excellent qualities, making them desirable for sustainable biofuel production.

Lipidomic Profiling of Rice Bran after Green Solid-Liquid Extractions for the Development of Circular Economy Approaches.

Rice bran is a rather underutilized by-product of the rice industry that nowadays is far from being valorized. In this study, the lipidomic profile of bran of the Italian rice variety, Roma, has been evaluated through ultra performance liquid chromatography-tandem mass spectrometry. Crude lipid extracts were obtained from rice bran treated with different green solvents (1-butanol, ethanol and methyl tert-butyl ether/methanol mixture) in combination with an ultrasonic pre-treatment, and then compared with extracts obtained with standard solvents (chloroform/methanol mixture). Lipid yield, number and type of lipids and composition of prevalent lipid classes extracted were evaluated in order to provide an exhaustive lipid profile of the rice bran and to identify the most efficient green solvent for solid-liquid extractions. Twelve different lipid classes and a maximum of 276 lipids were identified. Ethanol and methyl tert-butyl ether/methanol solvents provided higher lipid extraction yields, the former being the most effective solvent for the extraction of triglycerides and N-acylethanolamines and the latter the most effective for the extraction of diglycerides, phospholipids and ceramides at 4 °C. Moreover, extraction with ethanol at 20 °C gave similar results as at 4 °C in terms of lipid yield and for most of the classes of lipids extracted. Taken together, our results indicate ethanol and methyl tert-butyl ether/methanol as excellent solvents for lipid extraction from rice bran, with the aim to further valorize this food by-product in the perspective of a circular economy.

Post-incubation pH Impacts the Lipid Extraction Assisted by Pulsed Electric Fields from Wet Biomass of Auxenochlorella protothecoides

Pulsed electric field (PEF) treatment is a promising technology for efficient lipid extraction from microalgae. This study focusses on under-investigated processing parameters, such as media pH, pulse application, and incubation protocols. The lipid yield and electroporation level of PEF-treated Auxenochlorella protothecoides were determined at a medium pH of 3.0 and 5.0 under variation of the pre- or post-PEF incubation time and for split-dose treatments. Low energetic PEF treatments with 40 kV/cm and 1 μs pulses at 9.6 and 19.2 kJ/L were performed either in batch mode or in continuous flow. Post-PEF incubation significantly increased the shared electroporated cells (>60%) in medium pH 3.0, while no change was observed at pH 5.0. Split-dose PEF treatments at pH 5.0 caused significantly higher electroporation levels and lipid extraction yields than equivalent single-dose treatments. Results have shown that medium pH is critical in the final electroporation and lipid extraction yields of A. protothecoides and therefore should be considered in further studies.

Extraction possibilities of lipid fraction and authentication assessment of chaga (Inonotus obliquus)

Chaga (Inonotus obliquus) (Fr.) Pilát is a black perennial fungus that grows on adult birch trunks and has been traditionally used as a health promoting remedy in different countries. The lipophilic compounds of chaga were isolated applying conventional (Soxhlet), intensive (ultrasound assisted, accelerated solvent extraction) and environmentally friendly (supercritical fluid) extraction methods utilizing both polar and non-polar solvents. Soxhlet extraction showed the highest inotodiol yield (231 mg/100 g chaga) using cyclohexane. For authentication of chaga samples, isotope ratio mass spectrometry (IRMS) and multi-elemental analysis was performed. The extraction yield and profile of lipids, sterols and triterpenoids depend on the chaga origin. The amount of lipids in chaga samples varied in the range from 0.5 to 1.0%. The antimicrobial activity of chaga extracts against pathogenic and opportunistic pathogenic microorganisms was demonstrated. The results showed that extraction using supercritical CO2 delivered yields comparable to those obtained by conventional and intensive extraction techniques. Amount of target compounds (sterols and triterpenoids) obtained using supercritical CO2 extraction could represent the future for sustainable industrial-scale production of biologically active ingredients with antimicrobial activity. Authentication using IRMS allowed to differentiate between natural (fruiting bodies) and cultivated (mycelium) chaga.

CO2-triggered switchable solvent for lipid extraction from microalgal biomass

This study proposed a novel and energy-efficient method using switchable polarity solvents for lipid recovery from microalgae. Different from the existing methods, use of switchable polarity solvents does not require the fractional distillation for separation of lipid and solvent by only converting the polarity of the solvent after lipid extraction. When a non-polar amine solvent reacts with CO2, amino group (NH) can be transformed to a polar form, i.e. carbamate (NHCOO−). Nuclear magnetic resonance (NMR) spectrum indicated that only secondary amines are convertible to a polar compound of carbamate after CO2 treatment. The polarity switching potential of each amine candidate was quantitatively evaluated by normalized polarity energy (ETN). Dipropylamine (DPA) showed the greatest change in ETN from 0.452 to 0.789 kcal/mol (ETN of water = 1.0 kcal/mol) before and after CO2 treatment. DPA is a potential polarity switchable solvent capable of achieving an excellent lipid extraction yield of 7.51% from tested microalgal biomass (Chlorella vulgaris) with 9.16% of total lipid content and 95.5% fatty acid methyl esters (FAMEs) content. Furthermore, the used solvent could be recovered at the high efficiency of 84.0%. With a significant polarity switchability from nonpolar amine to carbamate in the presence of CO2, DPA, a secondary amine, could be suggested as a suitable solvent used for both extraction of lipids with a higher FAMEs content from microalgae and separation of lipid by only adding CO2.

Extraction of non-starch lipid from protease-treated wheat flour.

Lipids account for 2.0-2.5% of wheat flour by dry weight and affect properties and quality of cereal foods. A new method was developed to extract non-starch lipids from wheat flour. Wheat flour was first hydrolyzed with a protease and followed by extraction of non-starch lipids by water-saturated butanol (WSB). Protein hydrolysis by protease followed by extraction of non-starch lipids with WSB increased yield to 1.9 ± 0.3% from 1.0 ± 0.1% with no protease treatment. The lipid profile showed a significant increase in phospholipid compounds extracted with protease hydrolysis (5.9 ± 0.8 nmol·g-1 ) versus without enzymatic treatment (2.4 ± 1.3 nmol g-1 ). Improved lipid extraction yield and phospholipid compounds following protease-assisted extraction method provided additional insight towards the understanding of protein-lipid interaction in wheat flour. The new protease-assisted extraction method may be applied to analyzing non-starch lipids in other types of wheat flours and other cereal flours. © 2021 Society of Chemical Industry.

Direct extraction of lipids from wet microalgae slurries by super-high hydrostatic pressure

Microalgae are undergoing intense study as feedstock to produce biodiesel. However, due to the relatively low price of biodiesel, microalgae have recently been considered a novel source of food and functional products because they contain valuable natural products. Lipid extraction from wet microalgae slurries is considered an energy-saving extraction technique and often includes the use of liquid CO2, switchable solvent, organic solvent, dimethyl ether, and other pre-treatment methods. These methods led to either low extraction efficiencies additional treatment of the residue, or both. Therefore, super-high hydrostatic pressure (100–1000 MPa) is a processing technology mainly applied in the food industry for non-thermal sterilization that could offer several benefits: 1) a super-high pressure can disrupt cells and increase extraction yield; 2) non-thermal treatment will guarantee the extraction of biofunctional products without limited destruction; and 3) a super-high pressure saves energy costs for sterilization and denaturation of the residue, which could be used as a commercial edible protein or animal feed. However, there are no previous reports about lipid extraction by super-high hydrostatic pressure from wet microalgae slurries or regarding considerable challenges. In this study, we investigated two types of extraction from wet microalgae slurries by super-high hydrostatic pressure: one-step extraction and two-step extraction. We also compared the super-high hydrostatic pressure technique with high-pressure homogenization, ultrasonication and microwave extraction by evaluating cell disruption and lipid extraction yields. The highest cell disruption of 92.8 ± 2.7% and lipid extraction yield of 11.4 ± 0.4% were obtained when super-high hydrostatic pressure (SHHP) was applied in the one-step extraction process. In the two-step extraction process, the highest cell disruption of 87.8 ± 2.3% and lipid extraction yield of 10.1 ± 0.7% were obtained by SHHP treatment which was higher than those achieved by the other three treatments with the same wet microalgae slurry. Thus, SHHP can achieve high cell disruption and lipid extraction yields from wet microalgae slurries through the one-step extraction method.

Implementation in lipid extraction and analysis from phytoplankton: Skeletonema marinoi as case study

Microalgae, dominating protists in aquatic systems, are rich in lipids, a complex molecular class regulating cell physiology and phytoplankton ecology. Investigation of microalgal lipid metabolism is increasing, but common strategies for comprehensive lipid analyses are still lacking. Major methodological gaps are represented by separate analytical procedures for extraction and characterization of lipid molecules, thus hindering accurate comparison of metabolic data. Herein we propose one unique methodology for sample collection, extraction and analysis of main lipid mediators (oxylipins, fatty acids, glycerolipids, sterols and sterol derivatives) from diatoms. Extractions relied on the MTBE/methanol method, which provides high lipid extraction yields, involving either MeOH or water preparation of samples. Experiments focused on Skeletonema marinoi, a diatom species often used as model organism in plankton chemical ecology. Extraction protocols were implemented to characterize oxylipins and glycerolipids from algal cells collected as pellets or accumulated on glass-fibre filters, thus providing a practical tool to study multiple lipid classes in natural phytoplankton.

Improving the lipid extraction yield from Chlorella based on the controllable electroporation of cell membrane by pulsed electric field

In order to solve the increasingly serious problems of energy and environment, microalgae are used as a raw material for extracting lipids to produce biodiesel. Prior to the extraction of lipids, microalgae were treated with high-voltage pulsed electric field (PEF) to break the cell membrane. It was found that the lipid extraction yield depends on the electric field strength (E) and the specific energy input (Wsp), and has a certain relationship with the cell disintegration rate of Chlorella. The perforation degree of the Chlorella's cell membrane by PEF treatment is controllable, moderate perforation can be ensured by controlling the power parameters. PEF treatment significantly improved the extraction yield of lipids. Compared with the test samples without PEF treatment, PEF treatment increased the lipid extraction yields by up to 166.67%. However, an excessively high voltage will cause the quality of the extracted biodiesel to decrease.

Techniques of lipid extraction from microalgae for biofuel production: a review

Microalgae are feedstocks for production of carbon-neutral biofuels. Efforts have been performed to market microalgae biofuels, yet the production of microalgae biofuel remains a challenge due to the high production cost and low product yield. In particular, lipid extraction is a critical step to be optimized. Here, we review lipid extraction technologies and cell lysis strategies. Extraction techniques involve solvents such as organic solvents, supercritical fluids, ionic liquids, deep eutectic solvents and switchable solvents. Advantages and shortcomings of solvents are discussed. Besides, strategies have been designed to reduce power costs by integration of unit operations in downstream processing. We present single-step processes for simultaneous cell lysis and lipid extraction, such as ultrasound-, microwave-, bead-beating-, surfactant- and pulsed electric field-assisted extractions. The lipid extraction yield is enhanced by incorporating cell disruption into the lipid extraction process.

Electro-Fenton Based Technique to Enhance Cell Harvest and Lipid Extraction from Microalgae

Currently, lipid extraction remains a major bottleneck in microalgae technology for biofuel production. In this study, an effective and easily controlled cell wall disruption method based on electro-Fenton reaction was used to enhance lipid extraction from the wet biomass of Nannochloropsis oceanica IMET1. The results showed that 1.27 mM of hydroxide radical (HO•) was generated under the optimal conditions with 9.1 mM FeSO4 in a 16.4 mA·cm−2 current density for 37.0 min. After the electro-Fenton treatment, the neutral lipid extraction yield of microalgae (~155 mg) increased from 40% to 87.5%, equal to from 12.2% to 26.7% dry cell weight (DCW). In particular, the fatty acid composition remained stable. The cell wall disruption and lipid extraction processes were displayed by the transmission electron microscope (TEM) and fluorescence microscopy (FM) observations, respectively. Meanwhile, the removal efficiency of algal cells reached 85.2% within 2 h after the reaction was terminated. Furthermore, the biomass of the microalgae cultured in the electrolysis wastewater treated with fresh nutrients reached 3 g/L, which is 12-fold higher than that of the initial after 24 days. These finds provided an economic and efficient method for lipid extraction from wet microalgae, which could be easily controlled by current magnitude regulation.