Cassandra Breil

Microwave, ultrasound, thermal treatments, and bead milling as intensification techniques for extraction of lipids from oleaginous Yarrowia lipolytica yeast for a biojetfuel application.

In the present work, two different ways of lipids extraction from Yarrowia lipolytica yeast were investigated in order to maximize the extraction yield. Firstly, various modern techniques of extraction including ultrasound, microwave, and bead milling were tested to intensify the efficiency of lipid recovery. Secondly, several pretreatments such as freezing/defrosting, cold drying, bead milling, and microwave prior two washing of mixture solvent of chloroform:methanol (1:2, v/v) were study to evaluate the impact on lipid recovery. All these treatments were compared to conventional maceration, in terms of lipids extraction yield and lipid composition analysis. The main result of this study is the large difference of lipid recovery among treatments and the alteration of lipids profile after microwave and ultrasound techniques.

Bio-Based Solvents for Green Extraction of Lipids from Oleaginous Yeast Biomass for Sustainable Aviation Biofuel.

Lipid-based oleaginous microorganisms are potential candidates and resources for the sustainable production of biofuels. This study was designed to evaluate the performance of several alternative bio-based solvents for extracting lipids from yeasts. We used experimental design and simulation with Hansen solubility simulations and the conductor-like screening model for realistic solvation (COSMO-RS) to simulate the solubilization of lipids in each of these solvents. Lipid extracts were analyzed by high performance thin-layer chromatography (HPTLC) to obtain the distribution of lipids classes and gas chromatography coupled with a flame ionization detector (GC/FID) to obtain fatty acid profiles. Our aim was to correlate simulation with experimentation for extraction and solvation of lipids with bio-based solvents in order to make a preliminary evaluation for the replacement of hexane to extract lipids from microorganisms. Differences between theory and practice were noted for several solvents, such as CPME, MeTHF and ethyl acetate, which appeared to be good candidates to replace hexane.

“Bligh and Dyer” and Folch Methods for Solid–Liquid–Liquid Extraction of Lipids from Microorganisms. Comprehension of Solvatation Mechanisms and towards Substitution with Alternative Solvents

Bligh and Dyer (B & D) or Folch procedures for the extraction and separation of lipids from microorganisms and biological tissues using chloroform/methanol/water have been used tens of thousands of times and are gold standards for the analysis of extracted lipids. Based on the Conductor-like Screening MOdel for realistic Solvatation (COSMO-RS), we select ethanol and ethyl acetate as being potentially suitable for the substitution of methanol and chloroform. We confirm this by performing solid-liquid extraction of yeast (Yarrowia lipolytica IFP29) and subsequent liquid-liquid partition-the two steps of routine extraction. For this purpose, we consider similar points in the ternary phase diagrams of water/methanol/chloroform and water/ethanol/ethyl acetate, both in the monophasic mixtures and in the liquid-liquid miscibility gap. Based on high performance thin-layer chromatography (HPTLC) to obtain the distribution of lipids classes, and gas chromatography coupled with a flame ionisation detector (GC/FID) to obtain fatty acid profiles, this greener solvents pair is found to be almost as effective as the classic methanol-chloroform couple in terms of efficiency and selectivity of lipids and non-lipid material. Moreover, using these bio-sourced solvents as an alternative system is shown to be as effective as the classical system in terms of the yield of lipids extracted from microorganism tissues, independently of their apparent hydrophilicity.

A green analytical chemistry approach for lipid extraction: computation methods in the selection of green solvents as alternative to hexane

AbstractThere is a great interest in finding alternatives and green solvents in extraction processes to replace petroleum based solvents. In order to investigate these possibilities, computational methods, as Hansen solubility parameters (HSP) and conductor-like screening model for real solvent (COSMO-RS), were used in this work to predict the solvation power of a series of solvents in salmon fish lipids. Additionally, experimental studies were used to evaluate the performance in lipids extraction using 2-methyltetrahydrofurane, cyclopentyl methyl ether, dimethyl carbonate, isopropanol, ethanol, ethyl acetate, p-cymene and d-limonene compared with hexane. Lipid classes of extracts were obtained by using high performance thin-layer chromatography (HPTLC), whereas gas chromatography with a flame ionization detector (GC/FID) technique was employed to obtain fatty acid profiles. Some differences between theoretical and experimental results were observed, especially regarding the behavior of p-cymene and d-limonene, which separate from the predicted capability. Results obtained from HPTLC indicated that p-cymene and d-limonene extract triglycerides (TAGs) and diglycerides (DAGs) at levels of 73 and 19%, respectively, whereas the other studied extracts contain between 75 and 76% of TAGs and between 16 and 17% of DAGs. Fatty acid profiles, obtained by using GC-FID, indicated that saturated fatty acids (SFAs) between 19.5 and 19.9% of extracted oil, monounsaturated fatty acids (MUFAs) in the range between 43.5 and 44.9%, and PUFAs between 31.2 and 34.6% were extracted. p-Cymene and limonene extracts contained lower percentages than the other studied solvents of some PUFAs due probably to the fact that these unsaturated fatty acids are more susceptible to oxidative degradation than MUFAs. Ethyl acetate has been found to be the best alternative solvent to hexane for the extraction of salmon oil lipids.n Graphical Abstractᅟ

Manothermosonication as a useful tool for lipid extraction from oleaginous microorganisms

Manothermonication is a recognized and efficient method used for sterilization in food preservation. The synergistic effect of sonication combined with pressure and temperature allows enhancing the cavitation activity. Never employed for extraction, this study is about the transposition of this process as a tool of extraction. In this study, Rhodosporidium toruloides yeast was submitted to extraction by four modes of sonication, with a temperature ranged from 20 to 55°C and a pressure between 1 to 2bars. The lipids extraction yields were compared to the conventional maceration. Microbial oils obtained from both processes were analyzed and quantified by HPTLC (High Performance Thin-Layer Chromatography) and GC-FID (Gas Chromatography with flame ionization detector) after transesterification of lipids. Manothermosonication (30min, 2bars, 55°C) permits to enhance of approximately 20% the extraction yield of lipids to compared to conventional maceration. The fatty acid profiles of each pretreatment and extraction by US, MS, TS and MTS do not affect the fatty acid profiles of yeast (majority of oleic acid (C18:1n9), linoleic acid (C18:2n6) and palmitic acid (C16:0)). Manothermosonication technique shows a great potential for lipid extraction from oleaginous microorganisms.

Determination of fatty acids and lipid classes in salmon oil by near infrared spectroscopy

Near-infrared (NIR) spectroscopy was evaluated as a rapid method for the determination of oleic, palmitic, linoleic and linolenic acids as well as omega-3, omega-6, and to predict polyunsaturated, monounsaturated and saturated fatty acids, together with triacylglycerides, diglycerides, free fatty acids and ergosterol in salmon oil. To do it, Partial Least Squares (PLS) regression models were applied to correlate NIR spectra with aforementioned fatty acids and lipid classes. Results obtained were validated in front of reference procedures based on high performance thin layer and gas chromatography. PLS-NIR has a good predictive capability with relative root mean square error of prediction (RRMSEP) values below or equal to 1.8% and provides rapid analysis without the use of any chemicals making it an environmentally friendly methodology.

Innovative Techniques and Alternative Solvents for Extraction of Microbial Oils

This chapter reviews the recent development of extraction techniques, procedures and solvents for lipids from microorganisms. The modern innovative and intensified extraction techniques, alternative solvents and original procedures (ultrasound, microwave, supercritical fluid extraction, biobased-solvent, mechanical extraction, enzyme-assisted extraction, Instant controlled pressure drop, pulse electric field) are summarized in terms of their principles, processes, applications, benefits and disadvantages.

Analytical Methodology for Lipid Extraction and Quantification from Oleaginous Microorganisms

This chapter reviews the development of extraction and analytical techniques for lipids from microorganisms. The commonly used extraction techniques of total lipid such as «Folch», «Bligh and Dyer», and Soxhlet Extraction methods are detailed and explained. A special focus has been made for the complementary analytical methods such as HP-TLC (High Performance Thin Layer Chromatography) which gives details about the repartition of the different classes of lipids and GC (Gas Chromatography) which brings quantitative analysis of all fatty acids chains present in the lipid microbial extract.

Microorganisms: Source of High Value Added Compounds

This chapter presents the potential of primary and secondary metabolites produced by microorganisms after a brief introduction of their classification and detailing their cell wall structure. Furthermore, applications of microorganisms as sources of reagents and ingredients in various industries: food, cosmetic, pharmaceutics, nutraceutics, and biofuel.