Incorporation and Accumulation of Docosahexaenoic Acid from the Medium by Pichia methanolica HA-32

Yeast species were screened for the incorporation and accumulation of docosahexaenoic acid (DHA) with a yeast-malt medium containing 0.5% free fatty acid prepared from fish oil (DHA, 28% of total fatty acids in fish oil). The most suitable strain was Pichia methanolica HA-32. The optimum cultivation conditions for the accumulation of lipids and incorporation of DHA were as follows: 5% glucose, 20% yeast extract, and 3% free fatty acid in the medium, at pH 6.0 and with incubated at 25°C for 3 days. Under these conditions, about 200 mg of total lipids and 60 mg of DHA were recovered from 1 g of dry cells. The accumulation of DHA in cells increased in conjunction with the amount of yeast extract added to the medium. Vitamin B groups and minerals also had an effect on the accumulation of DHA. Choline and K₂HPO₄, which caused browning of the medium, promoted the accumulation of DHA in cells.     

Incorporation of eicosapentaenoic and docosahexaenoic acids by a yeast (FO726A)

An eicosapentaenoic acid (EPA)- and docosahexaenoic acid (DHA)-incorporating yeast, FO726A, was putatively identified as Candida guilliermondii on the basis of morphological, physiological and biochemical characteristics. Culture conditions for FO726A were investigated with respect to cell mass productivity, cellular accumulation of total lipid, triglyceride (TG), EPA and DHA. When grown at 20 degrees C for 24 h in an optimal medium containing 1 g scrap fish oil, the yeast yielded 820 mg dry cells which consisted of 40.7% lipid, 40.2% protein and 14.1% carbohydrate. The lipid (334mg) consisted of 300 mg TG (36.6% of dry cells), 23.2 mg EPA (2.8%) and 54.8 mg DHA (6.7%), and the recovery rates of EPA and DHA from the fish oil were 27.1 and 43.6%, respectively. The positional distributions of fatty acids in the TG from the yeast were then investigated and compared with those in the TG from the fish oil. The EPA and DHA in the fish oil were concentrated more in the sn-1,3 positions (8.8 and 13.7%, respectively) than in the sn-2 position (3.7 and 10.8%, respectively). In the case of the TG from the yeast, EPA was present to a greater extent in the sn-1,3 positions than in the sn-2 position. In contrast, DHA was preferentially present in the sn-2 position, approximately twice that in the sn-1,3 positions.     

Concentration of docosahexaenoic acid from fish oils using Geotrichum sp. FO347-2.

Geotrichum sp. FO347-2 could use refined sardine oil as a sole carbon source. Dry cell mass reached a maximum of 0.788 g per g of the oil added for 72 h. Total weight of the cellular lipids was largest around 24 h, when the contents of triglyceride and free fatty acid were 63.6 and 22.2%, respectively. Docosahexaenoic acid (DHA) was incorporated and concentrated in the cellular lipids, and the content reached 25.9% for 24 h, adding sardine oil containing 12.3% DHA. DHA and eicosapentaenoic acid were also concentrated in residual lipids outside the cells. Using tuna head oil containing 26.8% DHA, FO347-2 was compared with Candida guilliermondii FO726A with respect to DHA incorporation. FO347-2 and FO726A accumulated similar amounts of DHA, i.e. 53 and 55 mg, respectively, in 1 g of freeze-dried cells after 24-h cultivation at 30 degrees C. The recovery rates of DHA from the tuna oil for FO347-2 and FO726A were 19.4 and 19.7%, respectively.     

Enzymatic preparation of [1-13C]d-fructose-6-phosphate from [13C]formaldehyde and d-ribose-5-phosphate using the formaldehyde-fixing system of Methylomonas aminofaciens 77a

The intracellular concentration of 5,8,11,14,17-cis-eicosapentaenoic acid (EPA) and 4,7,10,13,16,19-cis-docosahexaenoic acid (DHA) was carried out by Mortierella alpina 1S-4 in a medium containing fish oil as the main carbon source. The EPA and DHA contents reached 29.2% and 20.0% of total fatty acids, respectively, when the fungus was grown in a medium containing salmon oil (EPA and DHA contents, 14.0% and 17.3%, respectively) as the main carbon source in a 5-1 bench-scale fermentor. EPA and DHA in the added fish oil were incorporated into both the mycelial polar lipids and triglycerides.On leave from Suntory Ltd. Correspondence to: S. Shimizu     

Fish oil fatty acids impair VLDL assembly and/or secretion by cultured rat hepatocytes

We determined the effect of the two major fish oil fatty acids, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), on VLDL assembly and secretion by cultured rat hepatocytes. The incorporation of [3H]glycerol into total triglyceride (cell plus media) was stimulated eight-fold when hepatocytes were incubated for 2 h with 1 mM EPA, DHA, or oleic acid (OA), suggesting that fish oil fatty acids stimulate hepatic triglyceride synthesis to an extent similar to OA. In contrast, mass quantitation of secreted triglyceride showed impaired triglyceride secretion with EPA and DHA compared to OA. During a 42-h time course, cells stimulated with EPA and DHA progressively accumulated triglyceride compared to cells stimulated with OA. To determine whether fish oil fatty acids impair very low density lipoprotein (VLDL) secretion, cells were labeled with [35S]methionine and the secretion of de novo synthesized apoB was measured. Compared to OA, EPA and DHA significantly impaired the secretion of both molecular weight forms of apoB. The cellular content of apoB was not altered by any of the fatty acids. The concordant decrease in the secretion of both triglyceride and apoB suggests that fish oil fatty acids impair VLDL assembly and/or secretion.     

不同氮和磷培养条件下等鞭金藻的生长、磷吸收和油脂品质的分析

为探索不同水平N和P对等鞭金藻(Isochrysis galbana Parke)产量及油脂品质的影响,在富N(80.00 mg·L-1 NO3--N)和无N(0.00 mg·L-1 NO3--N)条件下设置富P、限P和无P(20.00、0.25和0.00 mg·L-1 PO43--P)共6组培养基,对培养10 d时等鞭金藻的藻体质量浓度、P吸收量、总脂肪酸质量分数和脂肪酸产率变化、13个脂肪酸组分及其质量分数以及EPA和DHA的相对含量和产量进行了比较分析。结果显示：在富N培养基中,等鞭金藻藻体质量浓度的增幅明显高于无N培养基且按培养基中P质量浓度从高到低依次降低。总体上看,随培养时间延长,等鞭金藻的总脂肪酸质量分数持续升高,且在富N培养基中总脂肪酸质量分数高于无N培养基;其中,富N限P和富N无P培养基中的总脂肪酸质量分数基本上均高于富N富P培养基。富N培养基中各脂肪酸组分的质量分数大体上高于无N培养基,且限P培养基中各脂肪酸组分的质量分数大体上高于富P和无P培养基。在富N富P培养基中1 L藻体的P吸收量最高(0.0148 mg),并且吸收的P绝大部分被贮存在藻体中,而在无N富P培养基中P吸收量明显降低(0.0098 mg)。在富N富P培养基中,饱和脂肪酸质量分数和相对含量及EPA相对含量和产量均最低,但DHA相对含量和产量则最高。在富N限P培养基中,等鞭金藻的EPA产量和脂肪酸产率均最高,其DHA产量也较高;5种优质脂肪酸组分(即C18：1n9c、C16：0、C14：0、C18：0和C16：1n9)的总相对含量达到65.86%,尤其是C18：1n9c,其相对含量高达28.19%。综合分析结果显示：富N培养基有利于等鞭金藻的生长、P吸收及脂肪酸积累,其中,富N限P培养基是等鞭金藻高产且产优质油脂的适宜培养基。此外,等鞭金藻不但是生产生物柴油的优质资源而且是生产DHA和清除废水中P的潜在生物资源。     

Eicosapentaenoic and docosahexaenoic acids production by and okara-utilizing potential of thraustochytrids

Nine thraustochytrid strains isolated from subtropical mangroves were screened for their eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) production potential in a glucose yeast extract medium. Their ability to utilize okara (soymilk residue) for growth and EPA and DHA production was also evaluated. EPA yield was low in most strains, while DHA level was high on glucose yeast extract medium, producing 28.1–41.1% of total fatty acids, for all strains, with the exception of Ulkenia sp. KF13. The DHA yield of Schizochytrium mangrovei strains ranged from 747.7 to 2778.9 mg/l after 52 h of fermentation at 25°C. All strains utilized okara as a substrate for growth, but DHA yield was lower when compared with fermentation in a glucose yeast extract medium. Journal of Industrial Microbiology & Biotechnology (2001) 27, 199–202. Received 11 December 2000/ Accepted in revised form 29 June 2001     

Application of lipase to concentrate the docosahexaenoic acid (DHA) fraction of fish oil

A commercial lipase preparation from Rhizopus niveus was used to concentrate the omega-3 fatty acid, docosahexaenoic acid (DHA) component in fish oil. The DHA content of cod-liver oil was 9.64% (w/w) of total fatty acids. Enzymatic digestion conditions were established which produced a DHA content in the monoglycerides fraction of 29.17% (w/w) of total fatty acid, triglyceride, and diglyceride components were 5.72, 9.95, and 15316%, respectively.     

Metabolism of n -9, n -6 and n -3 fatty acids in hepatoma Morris 7777 cells. Preferential accumulation of linoleic acid in cardiolipin

The objective of this study was to investigate, using a pulse-chase technique, the different incorporation of (1-(14)C) n -9, n -6 and n 3 fatty acids into hepatoma lipids and their secretion to the culture medium. Docosahexaenoic acid (DHA) accumulated preferentially into the triacylglycerol while arachidonic acid (AA) did into the phospholipid fraction. DHA was poorly secreted to the culture medium whereas AA was secreted to a large extent. The fatty acids were initially esterified mainly into phosphatidylcholine and phosphatidylethanolamine. During the 24 h chase, a general shift from phosphatidylcholine to phosphatidylethanolamine was observed. Linoleic acid was esterified in cardiolipin to a much greater extent than any other fatty acid and it was not converted to more polyunsaturated fatty acids.The supplementation of the culture medium with polyunsaturated fatty acids had no inhibitory effect on the growth of the hepatoma cells, in marked contrast to observations made in other tumoral cells. The reasons for the resistance of the hepatoma cells to polyunsaturated fatty acid toxicity, including the possible antioxidant effect of linoleic acid accumulation in cardiolipin, are also discussed.     

Lipidomics of hepatic lipogenesis inhibition by omega 3 fatty acids

We assessed – by a lipidomic approach – the differential incorporation of EPA and DHA into hepatic lipids, after prolonged feeding of rats with fish oil. We also evaluated their effect on lipogenesis and its related enzymes. Rats were administered 100 mg/kg/d fish oil, by oral gavage, for 30 days. The fatty acid profile of total liver lipids was determined by gas–liquid chromatography coupled to mass spectrometry. Individual phospholipid classes and their molecular species were quantified by ESI-MS/MS. Omega 3 fatty acids readily incorporated into hepatic phospholipids, decreased stearoyl-CoA desaturase 16, stearoyl-CoA desaturase, delta 6 desaturase, and delta 5 desaturase activities (calculated as product/substrate ratio) and decreased the “lipogenesis index”, i.e., the proportion of fatty acids endogenously synthesized in the liver and not provided with the diet. Our results show that long-chain omega 3 fatty acids selectively incorporate into hepatic phospholipids, inhibit de novo lipogenesis and change the hepatic fatty acid profile via reduced desaturases' activity in the non-steatotic liver. In addition to corroborating advice to consume adequate amounts of omega 3 fatty acids for overall health, these data contribute mechanistic insights to the clinical observations that provision of omega 3 fatty acids decreases hepatic fat and ameliorates NAFLD prognosis.     

Identification of genes affecting lipid content using transposon mutagenesis in Saccharomyces cerevisiae

Genes involved in lipid accumulation were identified in Saccharomyces cerevisiae using transposon insertion mutagenesis. Five ORFs, such as SNF2, IRA2, PRE9, PHO90, and SPT21 were found from the analysis of the insertion sites in transposon insertion mutants with higher lipid content. Since these ORFs are not directly involved in storage lipid biosynthesis, we speculate that they are involved in carbon fluxes into storage lipids in response to nutrient conditions. Lipid analysis of disruptants of these ORFs indicated that the Deltasnf2, and Deltaira2 disruptants had significantly higher lipid content. Cultivation in a nitrogen-limited medium increased the lipid content in all disruptants, among which the Deltapre9 disruptant was the most sensitive to nitrogen limitation. We then focused on the Deltasnf2 disruptant due to its higher lipid content and its function as a regulator of phospholipid synthesis. Lipid class analysis indicated that triacylglycerol and free fatty acids contributed to the increase in total lipids of the Deltasnf2 disruptant. The addition of exogenous fatty acids was not so effective at increasing the lipid content in the Deltasnf2 disruptant as it was in the wild type. It should be noticed that exogenous free linoleic acid was much higher in the Deltasnf2 disruptant than in the wild type, as in the case of endogenous free fatty acids. In addition, the incorporation of exogenous fatty acids into cells increased in the disruptant, suggesting that fatty acid transporters were regulated by SNF2. The results suggest that metabolic fluxes into storage lipids, which are activated in the Deltasnf2 disruptant, is repressed by the incorporation of exogenous fatty acids. They provide new insight into the biosynthesis of storage lipids in yeast.     

Sequence-directed DNA Curvature in Activator-binding Sequence in the Escherichia coli kdpABC Promoter

Microorganisms that accumulated the eicosapentaenoic acid (EPA)-enriched triacylglycerol (TG), were screened for using yeast-malt medium containing 1% free EPA. The best strain was identified as Mucor hiemalis HA-30. The optimum culture conditions for the accumulation of EPA-enriched TG were : 3% soluble starch, 0.5% polypeptone, 0.3% yeast extract, 0.5% free EPA, and pH 6.0 at 25°C. After the cultivation, 1.77 mg/ml of the TG with EPA purity of 79% was obtained. The EPA content in TG increased in conjunction with the EPA content of the supplemented free fatty acids or ethyl esters. Free EPA were more efficiently incorporated than the ethyl esters. Trieicosapentaenoyl glycerol (EPA, EPA, EPA) accounted for 73% of total TGs.     

Dose dependent accretion of docosahexaenoic acid (DHA) in cardiac membranes of rats fed egg yolk powder enriched in DHA.

We tested the hypothesis that enrichment of the diet with docosahexaenoic acid (DHA) enriched egg yolk powder could modify specifically the (n-3) fatty acids content of rat plasma, red blood cells and heart membranes. Dose-dependent effect of DHA was studied in rats supplemented during 4 weeks. Three groups of adult male rats, DHA10, DHA35 and DHA60 (n = 5 each), had their diet supplemented with 10 mg, 35 mg or 60 mg DHA/kg body weight/day, respectively. Fatty acid composition of membranes and plasma lipids were determined. A significant dose-dependent increase in DHA was observed in all three types of samples. Arachidonic acid (AA) levels did not change in heart and red blood cell membranes whereas it increased significantly in plasma with the DHA35 diet. These results contrast with that previously reported for fish oil supplementation where a decrease in AA levels was reported. Hence, DHA enriched egg yolk supplementation leads to a specific accretion of DHA without competition on AA status.     

Distribution and metabolism of arachidonic and docosahexaenoic acids in rat pineal cells. Effect of norepinephrine

The time-course incorporation of 10 μM [¹⁴C]arachidonic (AA) and docosahexaenoic (DHA) acids into glycerolipids was studied in rat pineal cells. The incorporation of both labeled fatty acids into total lipids was approximately equal, but their distribution profiles among the various cell lipids showed marked differences. The esterification of [¹⁴C]DHA in the neutral lipids, triacylglycerols (TAG) and cholesterol esters (CE), was 2-fold higher than that of [¹⁴C]AA whereas the opposite could be observed in total phospholipids (PL). The order of incorporation into PL was phosphatidylcholine (PC) > phosphatidylinositol (PI) = phosphatidylethanolamine (PE) for [¹⁴C]AA and PC = PE for [¹⁴C]DHA, the incorporation of both fatty acids being not detected in phosphatidylserine (PS) and that of DHA not in PI. When using 0.5 μM [³H] fatty acids, the respective distribution patterns resembled that of fatty acids at 10 μM, except for a lower proportion in TAG. The stimulation of ³H-labeled cells by 100 μM norepinephrine induced a 170% increase of basal release of [³H]AA into the medium, while [³H]DHA was virtually not released. However, the analysis of cell labeling revealed that both [³H] fatty acid levels were decreased in PL and increased in TAG. These findings suggest different involvement for AA and DHA in the pineal function. The preferential incorporation of DHA in TAG suggests that TAG might play an important role in the pineal enrichment with DHA. The absence of DHA release after NE stimulation, which however cannot be ascertained, may raise the question of the role of DHA in NE transduction.     

Composition, accumulation and utilization of yolk lipids in teleost fish

Lipid reserves in teleost eggs are stored in lipoprotein yolk and, in some species, a discrete oil globule. Lipoprotein yolk lipids are primarily polar lipids, especially phosphatidylcholine and phosphatidylethanolamine (PE), and are rich in (n–3) polyunsaturated fatty acids, especially 22:6(n–3) (docosahexaenoic acid, DHA). Oil consists of neutral lipids and is rich in monounsaturated fatty acids (MUFA). Egg lipids are derived from dietary fatty acid, fatty acid mobilized from reserves and possibly fatty acid synthesized de novo. There is selective incorporation of essential fatty acids, particularly DHA, into yolk lipids and discrimination against incorporation of 22:1(n–11). Lipid is delivered to the oocyte by vitellogenin, which is rich in polar lipids, and likely also by other lipoproteins, especially very low density lipoprotein, which is rich in triacylglycerol (TAG). All classes of lipid may be used as fuel during embryonic and larval development and MUFA are preferred fatty acids for catabolism by embryos. Catabolism of oil globules is frequently delayed until latter stages of development. In some species, DHA derived from hydrolysis of phospholipid may be conserved by transfer to the neutral lipid. Recent work has expanded knowledge of the role of DHA in membrane structure, especially in neural tissue, and molecular species analysis has indicated that PE containing sn-1 oleic acid is a prime contributor to membrane fluidity. The results of this type of study provide an explanation for the selection pressures that influence yolk lipid composition. Future work ought to expand knowledge of specific roles of individual fatty acids in embryos along with knowledge of the ecological physiology of ovarian recrudescence, environmental influences on vitellogenin and yolk lipid composition, and the control of yolk lipid accumulation and utilization.     

Long-chain acyl-CoA synthetase 6 preferentially promotes DHA metabolism

Previously we demonstrated that supplementation with the polyunsaturated fatty acids (PUFA) arachidonic acid (AA) or docosahexaenoic acid (DHA) increased neurite outgrowth of PC12 cells during differentiation, and that overexpression of rat acyl-CoA synthetase long-chain family member 6 (Acsl6, formerly ACS2) further increased PUFA-enhanced neurite outgrowth. However, whether Acsl6 overexpression enhanced the amount of PUFA accumulated in the cells or altered the partitioning of any fatty acids into phospholipids (PLs) or triacylglycerides (TAGs) was unknown. Here we show that Acsl6 overexpression specifically promotes DHA internalization, activation to DHA-CoA, and accumulation in differentiating PC12 cells. In contrast, oleic acid (OA) and AA internalization and activation to OA-CoA and AA-CoA were increased only marginally by Acsl6 overexpression. Additionally, the level of total cellular PLs was increased in Acsl6 overexpressing cells when the medium was supplemented with AA and DHA, but not with OA. Acsl6 overexpression increased the incorporation of [(14)C]-labeled OA, AA, or DHA into PLs and TAGs. These results do not support a role for Acsl6 in the specific targeting of fatty acids into PLs or TAGs. Rather, our data support the hypothesis that Acsl6 functions primarily in DHA metabolism, and that its overexpression increases DHA and AA internalization primarily during the first 24 h of neuronal differentiation to stimulate PL synthesis and enhance neurite outgrowth.     

Isolation of a yeast growing on sardine oil and its characteristics

A yeast strain, FO-144Cl, was isolated from a soil sample, using crude sardine oil, which contains a large quantity of poly-unsaturated long-chain fatty acids, as a sole carbon source. This strain was identified as a species of Candida. A medium for its growth was optimized by statistical methods and optimal temperature for the growth was from 28 to 30°C. Among the natural oils and fats tested, the yeast grew best on olive oil and grew better on the crude sardine oil than on a refined one. The yield of dry cells was 17.6 mg/ml after 24 h, using 2% crude sardine oil. The maximum growth rate was 0.36, 0.25, and 0.21 h⁻¹ with crude sardine oil, soybean oil, and olive oil, respectively. The content of crude fat in the yeast cells was 15.1% and half of the total cell lipid was triglyceride. Fatty acid compositions of the lipid and oily fractions left in the medium after cultivation were analyzed. Little unsaturated long-chain fatty acids (>C₁₈) was observed in the cell lipids, but they were left concentrated in the medium.     

Divergent effects of eicosapentaenoic and docosahexaenoic acid ethyl esters, and fish oil on hepatic fatty acid oxidation in the rat

The physiological activity of fish oil, and ethyl esters of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) affecting hepatic fatty acid oxidation was compared in rats. Five groups of rats were fed various experimental diets for 15 days. A group fed a diet containing 9.4% palm oil almost devoid of n-3 fatty acids served as a control. The test diets contained 4% n-3 fatty acids mainly as EPA and DHA in the form of triacylglycerol (9.4% fish oil) or ethyl esters (diets containing 4% EPA ethyl ester, 4% DHA ethyl ester, and 1% EPA plus 3% DHA ethyl esters). The lipid content of diets containing EPA and DHA ethyl esters was adjusted to 9.4% by adding palm oil. The fish oil diet and ethyl ester diets, compared to the control diet containing 9.4% palm oil, increased activity and mRNA levels of hepatic mitochondrial and peroxisomal fatty acid oxidation enzymes, though not 3-hydroxyacyl-CoA dehydrogenase activity. The extent of the increase was, however, much greater with the fish oil than with EPA and DHA ethyl esters. EPA and DHA ethyl esters, compared to the control diet, increased 3-hydroxyacyl-CoA dehydrogenase activity, but fish oil strongly reduced it. It is apparent that EPA and DHA in the form of ethyl esters cannot mimic the physiological activity of fish oil at least in affecting hepatic fatty acid oxidation in rat.     

Influence of an increased intake of linoleic acid on the incorporation of dietary (n-3) fatty acids in phospholipids and on prostanoid synthesis in rat tissues.

We investigated whether the amount of dietary linoleic acid (LA) (as corn oil) influences the incorporation of dietary eicosapentaenoic acid (EPA) or docosahexaenoic acid (DHA) in tissue phospholipids and the prostanoid biosynthesis. Rats were fed four different levels of corn oil (at a total dietary fat level of either 2.5%, 5%, 10% or 20%); at each corn oil level, two groups of rats were supplemented with either EPA and DHA (200 mg/day) during 6 weeks, and compared with a group receiving oleic acid. The phospholipid fatty acid composition of liver, kidney and aorta showed, as expected, that the incorporation of EPA was highly suppressed by increasing the content of dietary linoleic acid in the diets. On the other hand, DHA was almost unaffected by the amounts of (n - 6) fatty acids in the diets. These results indicate that EPA levels but not DHA levels in tissue phospholipids were influenced by the competing dietary (n - 6) fatty acids. The tissue arachidonate content was similar under the various dietary linoleic acid conditions, but feeding EPA or DHA lowers the AA content. Moreover, the amount of dietary linoleic acid did not significantly influence the prostaglandin E2 (PGE2) production in stimulated aortic rings. However, PGE2 synthesis was significantly decreased in the groups treated with either EPA or DHA. Thromboxane B2 levels in serum followed a similar pattern. It is suggested that an increase of dietary (n - 3) PUFAs is more efficient to reduce (n - 6) eicosanoid formation than a decrease of dietary (n - 6) fatty acids.     

Single cell oil production by Yarrowia lipolytica growing on an industrial derivative of animal fat in batch cultures

The growth of an oleaginous strain of Yarrowia lipolytica on an industrial fat composed of saturated free fatty acids (stearin) was studied. Lipid accumulation during primary anabolic growth was critically influenced by the medium pH and the incubation temperature. This process was independent of the nitrogen concentration in the culture medium, but was favored at a high carbon substrate level and at a low aeration rate. At pH 6 and a temperature of 28-33 degrees C, 9-12 g/l of dry biomass was produced, whereas significant quantities of lipids were accumulated inside the yeast cells (0.44-0.54 g of lipid per gram of biomass). The strain showed the tendency to degrade its storage lipids, although significant amounts of substrate fat, rich in stearic acid, remained unconsumed in the culture medium. Y. lipolytica presented a strong fatty acid specificity. The fatty acids C12:0, C14:0, and C16:0 were rapidly incorporated and mainly used for growth needs, while C18:0 was incorporated with reduced rates and was mainly accumulated as storage material. Reserve lipids, principally composed of triacylglycerols (55% w/w of total lipids) and free fatty acids (35% w/w), were rich in stearic acid (80% w/w), while negligible amounts of unsaturated fatty acids were detected. When industrial glycerol was used as co-substrate, together with stearin, unsaturated fatty acid concentration in the reserve lipid increased.