Oleaginous Yeast Strains Research Articles

Oleaginous yeasts respond differently to carbon sources present in lignocellulose hydrolysate

BackgroundMicrobial oils, generated from lignocellulosic material, have great potential as renewable and sustainable alternatives to fossil-based fuels and chemicals. By unravelling the diversity of lipid accumulation physiology in different oleaginous yeasts grown on the various carbon sources present in lignocellulose hydrolysate (LH), new targets for optimisation of lipid accumulation can be identified. Monitoring lipid formation over time is essential for understanding lipid accumulation physiology. This study investigated lipid accumulation in a variety of oleaginous ascomycetous and basidiomycetous strains grown in glucose and xylose and followed lipid formation kinetics of selected strains in wheat straw hydrolysate (WSH).ResultsTwenty-nine oleaginous yeast strains were tested for their ability to utilise glucose and xylose, the main sugars present in WSH. Evaluation of sugar consumption and lipid accumulation revealed marked differences in xylose utilisation capacity between the yeast strains, even between those belonging to the same species. Five different promising strains, belonging to the species Lipomyces starkeyi, Rhodotorula glutinis, Rhodotorula babjevae and Rhodotorula toruloides, were grown on undiluted wheat straw hydrolysate and lipid accumulation was followed over time, using Fourier transform-infrared (FTIR) spectroscopy. All five strains were able to grow on undiluted WSH and to accumulate lipids, but to different extents and with different productivities. R. babjevae DVBPG 8058 was the best-performing strain, accumulating 64.8% of cell dry weight (CDW) as lipids. It reached a culture density of 28 g/L CDW in batch cultivation, resulting in a lipid content of 18.1 g/L and yield of 0.24 g lipids per g carbon source. This strain formed lipids from the major carbon sources in hydrolysate, glucose, acetate and xylose. R. glutinis CBS 2367 also consumed these carbon sources, but when assimilating xylose it consumed intracellular lipids simultaneously. Rhodotorula strains contained a higher proportion of polyunsaturated fatty acids than the two tested Lipomyces starkeyi strains.ConclusionsThere is considerable metabolic diversity among oleaginous yeasts, even between closely related species and strains, especially when converting xylose to biomass and lipids. Monitoring the kinetics of lipid accumulation and identifying the molecular basis of this diversity are keys to selecting suitable strains for high lipid production from lignocellulose.

Assessing oleaginous yeasts for their potentials on microbial lipid production from sugarcane bagasse and the effects of physical changes on lipid production

We assess oleaginous yeast strains from five genera to identify the strain suitable to use sugarcane bagasse as a feedstock for lipid production. Upon initial assessment in glucose or xylose media, five potential strains were chosen for further assessment in sugarcane bagasse hydrolysate. All strains exhibited improved growth and lipid production due to a buffering capacity of the hydrolysate, with R. glutinis showing the best lipid production. The yeast growth and lipid production were similar over the pH range between 5.5 and 7.5. It performed best at 30 °C. Using baffled flask at 200 rpm resulted in the highest cell dry weight of 40 g/L and 20 g/L of lipid, while using 100 rpm or normal flasks resulted in a much lower growth and lipid production. The results from this study suggest that sugarcane bagasse could be a raw material for microbial lipid production, providing the control criteria are suitable.

Valorisation of molasses by oleaginous yeasts for single cell oil (SCO) and carotenoids production

Abstract Two oleaginous yeast strains (Rhodosporodium toruloides and Rhodotorula glutinis) were examined for valorisation of molasses by the production of single cell oil (SCO) and carotenoid pigments. In the batch culture studies, the volumetric productivities of R. toruloides and R. glutinis were 3.41 and 2.47 g L−1 d−1 in the molasses medium, compared to that of 1.75 and 1.47 g L−1 d−1, respectively in the glucose yeast extract mineral (GYM) medium, at 96 h. R. toruloides grown in molasses medium yielded a maximum of 0.295 g of biomass g−1 of substrate consumed; whereas R. glutinis produced 0.226 g of biomass g−1 of the substrate consumed. The lipid contents of R. toruloides and R. glutinis were 53% and 45% in the molasses medium, and 48% and 43% in the GYM medium, respectively. R. glutinis grown in the GYM medium recorded the maximum carotenoid yield (0.045%), volumetric carotenoid productivity (0.027 mg L−1 h−1), and cellular carotenoid content ( 448 μ g g − 1 of cell dry weight). A significant increase in biomass and lipid yield was observed in molasses grown yeast as compared to GYM medium. Oleic acid (C18:1) was the predominant fatty acid present in R. toruloides cultivated in GYM medium. This study confirmed the potential of molasses with low C/N ratio for enhanced lipid production.

Exogenous l-proline improved Rhodosporidium toruloides lipid production on crude glycerol

BackgroundCrude glycerol as a promising feedstock for microbial lipid production contains several impurities that make it toxic stress inducer at high amount. Under stress conditions, microorganisms can accumulate l-proline as a safeguard. Herein, l-proline was assessed as an anti-stress agent in crude glycerol media.ResultsCrude glycerol was converted to microbial lipids by the oleaginous yeast Rhodosporidium toruloides CGMCC 2.1389 in a two-staged culture mode. The media was supplied with exogenous l-proline to improve lipid production efficiency in high crude glycerol stress. An optimal amount of 0.5 g/L l-proline increased lipid titer and lipid yield by 34% and 28%, respectively. The lipid titer of 12.2 g/L and lipid content of 64.5% with a highest lipid yield of 0.26 g/g were achieved with l-proline addition, which were far higher than those of the control, i.e., lipid titer of 9.1 g/L, lipid content of 58% and lipid yield of 0.21 g/g. Similarly, l-proline also improved cell growth and glycerol consumption. Moreover, fatty acid compositional profiles of the lipid products was found suitable as a potential feedstock for biodiesel production.ConclusionOur study suggested that exogenous l-proline improved cell growth and lipid production on crude glycerol by R. toruloides. The fact that higher lipid yield as well as glycerol consumption indicated that l-proline might act as a potential anti-stress agent for the oleaginous yeast strain.

Dataset of Nile Red Fluorescence Readings with Different Yeast Strains, Solvents, and Incubation Times

We used Nile red to estimate lipid content in oleaginous yeasts using a high-throughput approach. We measured the fluorescence intensity of Nile red using different solvents, yeast strains, and incubation times in optimized excitation/emission wavelengths. The data show the relative fluorescence units (RFU) for Nile red excitation, using 1× PBS, 1× PBS and 5% v/v isopropyl alcohol, 50% v/v glycerol, culture medium A-gly broth, and A-gly broth supplemented with 5% v/v DMSO. In addition, we showed the RFU for the Nile red dye for different oleaginous and non-oleaginous yeast strains, such as Meyerozyma guilliermondii BI281A, Yarrowia lipolytica QU21 and Saccharomyces cerevisiae MRC164. Other measurements of lipid accumulation kinetics were shown for the above and additional yeast strains. These datasets provide the guidelines to obtain the optimal solvent system and the minimal interaction time for the Nile red dye to enter in the cells and obtain a stable readout.

Mixed glycerol and orange peel-based substrate for fed-batch microbial biodiesel production

The aqueous extraction of orange peel waste (OPW), the byproduct of the juice extraction process generated annually in massive amounts (21 Mton), yields a carbohydrate-rich liquid fraction, termed orange peel extract (OPE). Several studies highlight that the combination of glycerol, a biodiesel byproduct, with carbohydrate mixtures might boost microbial lipid production. This study performed first a shaken flask screening of 15 oleaginous yeast strains based on their growth and lipid-producing abilities on OPE- and glycerol-based media. This screening enabled the selection of R. toruloides NRRL 1091 for the assessment of the process transfer in a stirred tank reactor (STR). This assessment relied, in particular, on either single- and double-stage feeding fed-batch (SSF-FB and DSF-FB, respectively) processes where OPE served as the primary medium and nitrogen-containing glycerol-OPE mixtures as the feeding one. The continuous supply mode at low dilution rates (0.02 and 0.01 h−1 for SSF-FB and DSF-FB, respectively) starting from the end of the exponential growth of the initial batch phase enabled the temporal extension of biomass and lipid production. The SSF-FB and DSF-FB processes attained high biomass and lipid volumetric productions (LVP) and ensured significant lipid accumulation on a dry cell basis (YL/X). The SSF-FB process led to LVP of 20.6 g L−1 after 104 h with volumetric productivity (rL) of 0.20 g L−1 h−1 and YL/X of 0.80; the DSF-FB process yielded LVP, rL and YL/X values equal to 15.92 g L−1, 0.11 g L−1 h−1 and 0.65, respectively. The fatty acid profiles of lipids from both fed-batch processes were not significantly different and resembled that of Jatropha oil, a vastly used feedstock for biodiesel production. These results suggest that OPE constitutes an excellent basis for the fed-batch production of R. toruloides lipids, and this process might afford a further option in OPW-based biorefinery.

Two-step optimization process for grass hydrolysate application as biodiesel feedstock with novel quality characteristics.

A major obstacle to biodiesel commercialization is supplying feedback which increases production costs. The potential of some oleaginous yeast for conversion of waste materials to biodiesel feedstock can overcome this problem. In this study, a potential oleaginous yeast strain was used for single-cell oil (SCO) production. Two sets of experiments were designed for the optimization process. According to the results obtained from the first experiment, lipid production and lipid content of this strain increased from 1.96g/L and 22.6% to 3.85g/L and 35.18% by optimization of grass hydrolysis, respectively. The results of the second experiment indicate an increase in SCO production and lipid content to 7.28g/L and 56.39%, respectively. These results were obtained when HNO3 was used for substrate pre-treatment. Lipid analysis by gas chromatography-mass spectrometry showed a suitable and high potential of fatty acid profile for biodiesel production, which was then confirmed by evaluating the physicochemical properties of the biodiesel obtained in compliance with the US and EU standards. Consumption of microbial oil and low-cost substrate can compensate the high costs of feedstock in biodiesel production.

High density cultivation of oleaginous yeast isolates in ‘mandi’ waste for enhanced lipid production using sugarcane molasses as feed

This study focuses on the use of synthetic and low cost carbon sources for enhanced biomass and lipid production from oleaginous yeast strains using batch and fed batch fermentation. Five strains were selected out of 20 strains which were all isolated from various habitats, on the basis of lipid accumulating potential using Sudan B black dye. The selected isolates were characterized and their lipid production was optimized by batch cultivation in waste extract. Gas chromatography analysis revealed that lipids from all isolated yeast strains contained mainly long-chain fatty acids such as oleic acid, palmitic acid, stearic acid and linoleic acid. On the basis of lipid profile and production, two most suitable oleaginous yeast strains were selected for further experiments, i.e. fed batch fermentation using glucose (control) and sugarcane molasses as feed. Using glucose as feed, 38.8 ± 0.9 g/L and 29.4 ± 0.2 g/L biomass dry cell weight (DCW) and total lipids were produced respectively, whereas with sugarcane molasses feed, 50 ± 1 g/L (DCW) biomass and 39.2 ± 0.6 g/L lipids were produced by Rhodosporidium toruloides ATCC204091. After transesterification the lipid profile was analyzed by GC–MS revealing suitability for use as a potential feedstock for biodiesel production.

Lipid Production from Amino Acid Wastes by the Oleaginous Yeast Rhodosporidium toruloides

Microbial lipids have been considered as promising resources for the production of renewable biofuels and oleochemicals. Various feedstocks, including sugars, crude glycerol, and volatile fatty acids, have been used as substrates for microbial lipid production, yet amino acid (AA) wastes remain to be evaluated. Here, we describe the potential to use AA wastes for lipid production with a two-stage culture mode by an oleaginous yeast strain Rhodosporidium toruloides CGMCC 2.1389. Each of the 20 proteinogenic AAs was evaluated individually as sole carbon source, with 8 showing capability to facilitate cellular lipid contents of more than 20%. It was found that L-proline was the most favored AA, with which cells accumulated lipids to a cellular lipid content of 37.3%. When blends with AA profiles corresponding to those of meat industry by-products and sheep viscera were used, the cellular lipid contents reached 27.0% and 28.7%, respectively. The fatty acid compositional analysis of these lipid products revealed similar profiles to those of vegetable oils. These results, thus, demonstrate a potential route to convert AA wastes into lipids, which is of great importance for waste management and biofuel production.

Simultaneous lipid production for biodiesel feedstock and decontamination of sago processing wastewater using Candida tropicalis ASY2

BackgroundWithout sufficient alternatives to crude oil, as demand continues to rise, the global economy will undergo a drastic decline as oil prices explode. Dependence on crude oil and growing environmental impairment must eventually be overcome by creating a sustainable and profitable alternative based on renewable and accessible feedstock. One of the promising solutions for the current and near-future is the substitution of fossil fuels with sustainable liquid feedstock for biofuel production. Among the different renewable liquid feedstock’s studied, wastewater is the least explored one for biodiesel production. Sago wastewater is the byproduct of the cassava processing industry and has starch content ranging from 4 to 7%. The present investigation was aimed to produce microbial lipids from oleaginous yeast, Candida tropicalis ASY2 for use as biodiesel feedstock and simultaneously decontaminate the sago processing wastewater for reuse. Initial screening of oleaginous yeast to find an efficient amylolytic with maximum lipid productivity resulted in a potent oleaginous yeast strain, C. tropicalis ASY2, that utilizes SWW as a substrate. Shake flask experiments are conducted over a fermentation time of 240 h to determine a suitable fatty acid composition using GC-FID for biodiesel production with simultaneous removal of SWW pollutants using ASY2.ResultsThe maximum biomass of 0.021 g L−1 h−1 and lipid productivity of 0.010 g L−1 h−1 was recorded in SWW with lipid content of 49%. The yeast strain degraded cyanide in SWW (79%) and also removed chemical oxygen demand (COD), biological oxygen demand (BOD), nitrate (NO3), ammoniacal (NH4), and phosphate (PO4) ions (84%, 92%, 100%, 98%, and 85%, respectively). GC-FID analysis of fatty acid methyl esters (FAME) revealed high oleic acid content (41.33%), which is one of the primary fatty acids for biodiesel production.ConclusionsIt is evident that the present study provides an innovative and ecologically sustainable technology that generates valuable fuel, biodiesel using SWW as a substrate and decontaminates for reuse.

Biodiesel-derived crude glycerol as alternative feedstock for single cell oil production by the oleaginous yeast Candida viswanathii Y-E4

In recent years, much attention has been paid to microbial lipids as promising raw materials for biodiesel production. The use of industrial by-products as carbon sources seems to be a feasible strategy for cost-effective lipid fermentation with oleaginous microorganisms on a large scale. In this work, biodiesel-derived crude glycerol was used as a renewable feedstock for microbial lipid production. Chemical characterization has shown that used crude glycerol sample is mainly composed of 64.5 % glycerol, 5.9 % methanol, 11 % water and 5.8 % ash in addition to other impurities. This industrial waste was used as only carbon source in the culture media of 13 oleaginous yeast strains. Candida viswanathii Y-E4 stood out above the other strains, achieving a higher amount of biomass and lipid content (17.2 g/L and 41 %, respectively). Culture conditions were optimized using response surface methodology to enhance the Y-E4 lipid yield. Box-Behnken model was performed to determine the optimum levels of three independent variables and the eventual effect of their interactions on the response. Under optimal conditions, the total biomass of 26.6 g/L with lipid content of 51.9 % (corresponding to a lipid yield of 13.6 g/L) could be achieved after 166 h of culture. The characterization of obtained lipid showed that fatty acids composition and lipid profile were very different between pure and crude glycerol based cultures, with a predominance of long-chain fatty acids, particularly polyunsaturated fatty acids such as linoleic acid (45 %). The predictive determination of biodiesel properties suggests that this oil may effectively be used for biodiesel manufacture. The current study, therefore, opens new perspectives in relation to the valorization of biodiesel-derived crude glycerol, through completely eco-friendly processes.

Microbial lipid production from dilute acid and dilute alkali pretreated corn stover via Trichosporon dermatis

Microbial lipid production from lignocellulosic biomass has attracted much attention recently. In this study, T. dermatis 32903 was selected from eleven promising oleaginous yeast strains. Carbon to nitrogen ratio (C/N) was investigated and optimized to maximize lipid production. Dilute acid (DA) pretreated corn stover (CS) and dilute alkali (AL) pretreated CS were then used for microbial lipid production, resulting in lipid concentrations of 7.46 g/L and 6.81 g/L, with sugar to lipid yields reached 0.104 g/g and 0.101 g/g, respectively. Washing of DA-CS and AL-CS enhanced lipid production to 11.43 g/L and 20.36 g/L with sugar to lipid yields improved to 0.156 g/g and 0.186 g/g, respectively. As degradation products in pretreated biomass showed severe inhibition on lipid fermentation, eight typical degradation products were further investigated for their effects on lipid fermentation. T. dermatis 32903 exhibited high tolerance to furan derivatives and week acids, but lower tolerance to phenolic compounds.

Optimization of culture conditions of Rhodotorula graminis S1/2R to obtain saponifiable lipids for the production of second-generation biodiesel

The use of biodiesel has generated a diversification of the energy matrix, which has led to a lower dependence on fossil fuels and a concomitant reduction of the adverse effects on the environment generated by their use. Currently, biodiesel is mainly produced by transesterification with short-chain alcohols of oils from different sources, in particular from oil crops, such as soybean and canola. Since the use of crops for the generation of fuels competes with their use as food, it seems appropriate to explore new oil sources for the production of biodiesel, such as the intracellular triglycerides accumulated by oleaginous yeasts. In this case, to achieve a competitive process, yeast production should be carried out using low-cost fermentable substrates such as industrial wastes or by-products. In this work we optimized the production of intracellular lipids by a previously selected oleaginous yeast strain in a fed-batch culture in presence of crude glycerol as a source of carbon and energy. In the optimized conditions an important improvement of lipid concentration was achieved, obtaining 12.2 g L−1 of fatty acid methyl esters (FAMEs) and 26.6 g L−1 of dry biomass in 360 h of culture.

Screening for Oily Yeasts Able to Convert Hydrolysates from Biomass to Biofuels While Maintaining Industrial Process Relevance.

Research has recently intensified to discover new oleaginous yeast strains able to function quickly and efficiently in low-cost lignocellulosic hydrolysates to produce high-quality lipids for use in biodiesel and chemicals. Detailed techniques are given here for ranking candidate yeast strains based on conversion of hydrolysate sugars to lipids and then optimizing cultivation conditions for best performers in a 96-well aerobic microcultivation format. A full battery of assays applicable to high throughput of small-volume samples are described for efficiently evaluating cell biomass production, lipid accumulation, fatty acid composition, and sugar utilization. Original data is additionally presented on the validation of the microtechnique for GC analysis of lipid composition in yeast since this application involved modification of a previously published assay for microalgae.

Activating de novo triacylglycerol synthesis in oleaginous yeast for improved bio-diesel quality

The economic production of yeast biofuels requires several strategies, such as multiomics techniques to gain insights into lipid biosynthesis pathway. Hence, metabolomic studies for amelioration of triacylglycerol (TAG) accumulation in oleaginous yeast strain to reveal potential targets in fatty acid synthesis pathway should be explored. The aim of this research experiment was to boost TAG agglomeration in novel isolated oleaginous yeast Cryptococcus psychrotolerans IITRFD using sodium bicarbonate as supplement for biodiesel production. Enhanced biomass productivity (83.5 ± 0.32 mg/L/h) and lipid productivity (56.8 ± 0.34 mg/L/h) have been estimated as compared to yeast nitrogen base media (YNB) used as control. Also, the bicarbonate supplementation (25 mM) leads to decrease in phospholipids (23.6 %) while increase in TAG amount (75.4 %) signifying that it redirects the phospholipids synthesis pathway in the direction of de novo TAG pathway. The fatty acid profile obtained revealed rise in monounsaturated fatty acid content and decrease in polyunsaturated fatty acid content demonstrating better oxidative stability (19 h) and cold flow behaviour (- 12 °C) of biodiesel produced. This novel strategy of utilizing bicarbonate as a triggering system may possibly revamp the commercial use of C. psychrotolerans IITRFD for high quality biodiesel production. This is the first study to augment TAG accumulation in this oleaginous yeast using sodium bicarbonate with improved fuel properties.

Selection of oleaginous yeasts capable of high lipid accumulation during challenges from inhibitory chemical compounds

A two-stage selection process was applied to eight oleaginous yeast strains from the Lipomyces genera. In the primary selection stage, a nitrogen-limited mineral medium (-NMM) that contained a mixture of glucose and xylose as a carbon source was used to evaluate the lipid-accumulating abilities of the yeast strains. The strains L. doorenjongii, L. orientalis, and L. starkeyi were selected as the potential strains in the primary selection. These three strains exhibited a remarkable ability to simultaneously assimilate glucose and xylose and achieved a cell biomass of more than 30 g/L. The values for lipid content in the selected strains were 57.89 ± 1.92, 56.38 ± 1.93, and 77.14 ± 1.55% for L. doorenjongii, L. orientalis, and L. starkeyi, respectively. In the secondary selection, when the -NMM medium contained an inhibitory chemical compound (ICC), the selected strains showed a different tolerance level against each of the typical inhibitor compounds. However, L. starkeyi accumulated the highest lipid content and yield at 68.24 ± 2.48% and 0.19 ± 0.00 (w/w), respectively. L. starkeyi accumulated high levels of intracellular lipid and tolerated the ICC. The composition of fatty acid methyl esters (FAMEs) was unaltered by the presence of ICC and the major FAMEs consisted of oleic, palmitic, stearic, palmitoleic and linoleic acids.

Recovery of Fuel-Precursor Lipids from Oleaginous Yeast

Bioderived lipids offer a potentially promising intermediate to displace petroleum-derived diesel. One of the key challenges for the production of lipids via microbial cell mass is that these products are stored intracellularly and must be extracted and recovered efficiently and economically. Thus, improved methods of cell lysis and lipid extraction are needed. In this study, we examine lipid extraction from wet oleaginous yeast in combination with seven different cell lysis approaches encompassing both physical and chemical techniques (high-pressure homogenization, microwave and conventional thermal treatments, bead beating, acid, base, and enzymatic treatments) to facilitate lipid extraction from a model oleaginous yeast strain, Lipomyces starkeyi. Of the seven techniques investigated, acid treatment led to the highest lipid recovery yields. Further exploration of acid treatment and integration with an economic model revealed that treatment at 170 °C for 60 min at 1 wt % H2SO4 and 8 wt % yeast solids re...

Evaluation of lipid production from xylose and glucose/xylose mixed sugar in various oleaginous yeasts and improvement of lipid production by UV mutagenesis

Microbial lipids from oleaginous yeasts are recognized as promising alternative lipid sources. Although lipid productivity of oleaginous yeasts from glucose has been well-studied, knowledge of lipid productivity from xylose is limited. In this study, we aimed to evaluate and improve lipid productivity from xylose or glucose/xylose mixed sugar in various oleaginous yeasts. The xylose-based growth capability of 15 oleaginous strains belonging to Cryptococcus curvatus, Lipomyces starkeyi, Rhodosporidium toruloides, and Rhodotorula glutinis was tested. L. starkeyi strains showed relatively low growth capability. Ultraviolet mutagenesis combined with selection using cerulenin was applied for C. curvatus and R. toruloides strains. A mutant R. toruloides 8766 3-11C 2-53C exhibiting higher lipid productivity from xylose and glucose/xylose was obtained. The transcription levels of various lipid production-related genes were upregulated, whereas xylose metabolism-related genes were almost unchanged in the mutant. The results reveal the very diverse xylose-utilizing capability in the various oleaginous yeast species and strains. Promising target genes to improve lipid productivity from xylose through gene recombination were identified.

Use of high-throughput techniques to study simultaneous production of lipid metabolites in carotenogenic yeasts grown on waste animal fat

This study focuses on the valorisation of crude glycerol and sunflower meal (SFM) from conventional biodiesel production plants for the separation of value-added co-products (antioxidant-rich extracts and protein isolate) and for enhancing biodiesel production through microbial oil synthesis. Microbial oil production was evaluated using three oleaginous yeast strains (Rhodosporidium toruloides, Lipomyces starkeyi and Cryptococcus curvatus) cultivated on crude glycerol and nutrient-rich hydrolysates derived from either whole SFM or SFM fractions that remained after separation of value-added co-products. Fed-batch bioreactor cultures with R. toruloides led to the production of 37.4 g L−1 of total dry weight with a microbial oil content of 51.3% (w w−1) when a biorefinery concept based on SFM fractionation was employed. The estimated biodiesel properties conformed with the limits set by the EN 14214 and ASTM D 6751 standards. The estimated cold filter plugging point (7.3–8.6 °C) of the lipids produced by R. toruloides is closer to that of biodiesel derived from palm oil.

Cocoa butter-like lipid production ability of non-oleaginous and oleaginous yeasts under nitrogen-limited culture conditions

Cocoa butter (CB) extracted from cocoa beans is the main raw material for chocolate production. However, growing chocolate demands and limited CB production has resulted in a shortage of CB supply. CB is mainly composed of three different kinds of triacylglycerols (TAGs), POP (C16:0–C18:1–C16:0), POS (C16:0–C18:1–C18:0), and SOS (C18:0–C18:1–C18:0). The storage lipids of yeasts, mainly TAGs, also contain relative high-level of C16 and C18 fatty acids and might be used as CB-like lipids (CBL). In this study, we cultivated six different yeasts, including one non-oleaginous yeast strain, Saccharomyces cerevisiae CEN.PK113-7D, and five oleaginous yeast strains, Trichosporon oleaginosus DSM11815, Rhodotorula graminis DSM 27356, Lipomyces starkeyi DSM 70296, Rhodosporidium toruloides DSM 70398, and Yarrowia lipolytica CBS 6124, in nitrogen-limited medium and compared their CBL production ability. Under the same growth conditions, we found that TAGs were the main lipids in all six yeasts and that T. oleaginosus can produce more TAGs than the other five yeasts. Less than 3% of the total TAGs were identified as potential SOS in the six yeasts. However, T. oleaginosus produced 27.8% potential POP and POS at levels of 378 mg TAGs/g dry cell weight, hinting that this yeast may have potential as a CBL production host after further metabolic engineering in future.