Mole Of Fatty Acid Research Articles

Direct Incorporation of Exogenous Glycerol Leads to Increased Triacylglycerol Formation in Chlorella vulgaris

Algal-based biofuels have the potential to significantly impact the global use of petroleum-based fuel sources without competing with agricultural feedstocks. Chlorella vulgaris, a unicellular green alga with a high growth rate and limited nutritional requirements, can produce up to 42% lipids per dry mass under stress conditions, making it a promising biofuel feedstock. Of all lipid classes, triacylglycerols (TAGs) are most desired, as three moles of fatty acids are generated from every one mole of TAGs. The process of transesterifying these fatty acids results in the generation of a glycerol waste product with little economic value. With the exposure of mixotrophically grown C. vulgaris to exogenous glycerol, overall TAG production was increased, likely as a function of lipid cycling from cell membranes. Furthermore, with the use of isotopically labeled glycerol and GC-MS, it was determined that the exogenously applied glycerol was directly incorporated into the TAG backbone, a novel finding. Thus, using the glycerol waste product of TAG transesterification has the potential to increase the efficiency of algal biofeedstocks, both by recycling a previously unused waste product as well as increasing the high-energy TAG percent within the cultures.

Utilization of Waste Glycerol from Biodiesel Process as a Substrate for Mono-, Di-, and Triacylglycerol Production

Glycerol (or glycerin) is a major by-product in the biodiesel process. Ten percent of crude glycerol are created for every 100 pounds of biodiesel produced. As the utilization of biodiesel increasing, an excess of glycerol is being generated. However, the purify of waste glycerol is expensive, biodiesel producers must search alternative methods for its utilization. This paper demonstrate the feasibility of producing mono-, di- and triacylglycerol from waste glycerol. The acylglycerol was produced through glycerolysis reaction using commercial lipase from Candida sp. Effects of various reaction parameters were evaluated. The optimum conditions for acylglycerol production were a glycerol to fatty acid mole ratio of 6∶1, 100 mg of lipase with the reaction temperature and time at 40°C and 24 h, respectively. Analysis of acylglycerol by Thin Layer Chromatography (TLC) using petroleum ether : diethyl ether :methanol:acetic acid (90:7:2.5:0.5 v/v) as mobile phase found that mono-, di- and triacylglycerol were produced in high purity. Interestingly, the highest production of acylglycerol yeild from commercial lipase and crude lipase from pacific white shrimp’s hepatopancreas were obtained at the same conditions. Attenuated Total Reflectance (ATR)-Fourier Transform Infrared Spectroscopy (FTIR) proved that the final product contains mono-, di- and triacylglycerol.

Esterification of oleic acid with ethanol in the presence of Amberlyst 15

Biodiesel is a promising cleaner burning, less toxic and renewable energy carrier. It is made primarily by transesterification of refined vegetable oils, but biodiesel from these sources are becoming more expensive. Therefore, alternative raw materials are being evaluated, but a major difficulty in the production of biodiesel from these alternative feedstocks is the high concentrations of free fatty acids. This is mainly due to the saponification reaction which occurs with the most commonly used alkali catalysts. Therefore in this work a parameter screening of the esterification of oleic acid, a free fatty acid, with ethanol in the presence of the heterogeneous acid catalyst Amberlyst 15 wet ion exchange was conducted with the intent to produce biodiesel. The parameters screened were reaction temperature, catalyst amount and the ratio between moles of alcohol and moles of fatty acid while the reaction time was set to 6 h. It was found that higher temperature and catalyst amounts increased conversion; however, the ratio between moles of alcohol and moles of fatty acid that gave the highest final conversion was 1:1. The highest Biodiesel yield obtained was 53%. In addition a reuse test of the catalyst was in order to test its recyclability; however, the catalyst presented a reduction in its activity after a single use.

Lipase catalyzed production of monoacylglycerols by the esterification of fish oil fatty acids with glycerol

In this study, we attempted the efficient production of monoacylglycerols (MAG) via the lipase-catalyzed esterification of glycerol with fatty acids obtained from sardine oil. The reaction factors that influenced MAG synthesis were the glycerol to fatty acid mole ratio, amount of enzyme, organic solvent, temperature, and the type of lipase used. Porcine pancreas lipase was selected to catalyze this reaction. The optimum conditions we determined for MAG synthesis were a glycerol to fatty acid mole ratio of 1∶6, 100 mg/mL of lipase, and 30°C in dioxane. Under these conditions, the MAG content was 68% (w/w) after 72 h of reaction. The MAGs synthesized via the lipase-catalyzed esterification of glycerol with fatty acids included monomyristin, monopamiltin, and monoolein, as identified by GCMS.

Differential distribution of proteins and lipids in detergent‐resistant and detergent‐soluble domains in rod outer segment plasma membranes and disks

Membrane heterogeneity plays a significant role in regulating signal transduction and other cellular activities. We examined the protein and lipid components associated with the detergent-resistant membrane (DRM) fractions from retinal rod outer segment (ROS) disk and plasma membrane-enriched preparations. Proteomics and correlative western blot analysis revealed the presence of alpha and beta subunits of the rod cGMP-gated ion channel and glucose transporter type 1, among other proteins. The glucose transporter was present exclusively in ROS plasma membrane (not disks) and was highly enriched in DRMs, as was the cGMP-gated channel beta-subunit. In contrast, the majority of rod opsin and ATP-binding cassette transporter A4 was localized to detergent-soluble domains in disks. As expected, the cholesterol : fatty acid mole ratio was higher in DRMs than in the corresponding parent membranes (disk and plasma membranes, respectively) and was also higher in disks compared to plasma membranes. Furthermore, the ratio of saturated : polyunsaturated fatty acids was also higher in DRMs compared to their respective parent membranes (disk and plasma membranes). These results confirm that DRMs prepared from both disks and plasma membranes are enriched in cholesterol and in saturated fatty acids compared to their parent membranes. The dominant fatty acids in DRMs were 16 : 0 and 18 : 0; 22 : 6n3 and 18 : 1 levels were threefold higher and twofold lower, respectively, in disk-derived DRMs compared to plasma membrane-derived DRMs. We estimate, based on fatty acid recovery that DRMs account for only approximately 8% of disks and approximately 12% of ROS plasma membrane.

A Novel Biosurfactant, 2-Acyloxyethylphosphonate, Isolated from Waterblooms of Aphanizomenon flos-aquae

A novel biosurfactant, 2-acyloxyethylphosphonate, was isolated from waterblooms of Aphanizomenon flos-aquae. Its structure was elucidated by chemical degradation and HRFABMS, GC/EI-MS and 1D- and 2D-NMR spectral analyses. The surfactant contained one mole of 2-hydroxyethylphosphonate and one mole of fatty acid, with hexadecanoic acid accounting for 84.1% of the total fatty acid content. The structure was confirmed by synthesis of 2-oleoyloxyethylphosphonate from ethylene oxide, phosphorus acid and oleic acid chloride. Considering the isolated surfactant molecule as hexadecanoyloxyethylphosphonic acid (mw. 364), the critical micelle concentration (CMC) was about 22 mM.

Evaluación de efectos difusionales sobre la cinética de hidrólisis de lecitina de soja con fosfolipasa A<sub>2</sub>

Soluble or immobilized A 2 phospholipase liberates one mole of fatty acid of the C-2 position in soybean lecithin phospholipids to product lysolecithins. When using the enzyme in its immobilized form the enzymatic activity decreases due to substrate and product transport phenomenon. By comparison of the kinetic parameters of the hydrolysis reaction catalized by A 2 phospholipase immobilized on alumina or on DEAE-Sephadex against those of the soluble enzyme, for soybean lecithin hydrolysis reaction, the diffusive effects were evaluated. The decrease of the reaction rate was quantified in presence of diffusive effects and the effectiveness factors were calculated. The Michaelis-Menten kinetic parameters were determined: K M = 8,2.10- 2 mol·l -1 and 5,36.10 -2 mol·l -1 and V max = 7,7.10 -5 mol·l -1 .min -1 and 9,5.10 -5 mol·l -1 ·min -1 for the enzyme immobilized on alumina and on DEAE-Sephadex, respectively. The effectiveness factors were 0,277 for alumina and 0,376 for DEAE-Sephadex.

Correlation of the fatty acid composition and fluid property of the cholesteryl esters in the serum of Nigerian children with sickle cell disease and healthy controls

In a previous study conducted in Nigeria, we found that children with sickle cell disease (SCD) had exceedingly low total serum cholesterol levels (mean=100−102 mg/dl). The fact that significant reductions in the levels of certain polyunsaturated fatty acids (PUFA) have been documented in the serum phospholipids of these same SCD subjects led us to inquire as to the fatty acid composition of the cholesteryl esters (CE) in their serum. Lecithin:cholesterol acyl transferase (LCAT), the enzyme in blood that catalyzes the reaction in which tissue cholesterol is acylated prior to its removal from cell membranes, is relatively specific for certain PUFA. CE in blood serum from 43 male and 42 female children with SCD, ages 4–18 years, and equal numbers of age- and gender-matched controls were analyzed for their fatty acid composition. Relative to the non-SCD controls, the CE of the SCD subjects contained 9% less linoleic acid, 16% less arachidonic acid, 40% less α-linolenic acid, 50% less eicosapentaenoic acid, and 36% less docosahexaenoic acid, but 15% more palmitic acid and 10% more oleic acid. Overall, the acyl chains of the CE of the SCD subjects were less fluid than those of the controls, as determined by comparison of their mean melting points (MMP) and double bond indices (DBI). MMP and DBI were both estimated from the individual constituent fatty acids comprising the CE acyl chains. The strongest correlations between MMP and fatty acid mole percent were seen with palmitic acid and linoleic acid. These results show that the fatty acid composition of the serum CE of children with SCD is abnormal relative to controls who do not have this hematologic disorder. We speculate that suboptimal fatty acid nutrition in Nigerian children with SCD compromises their ability to remove cholesterol from their tissues due to preference of the LCAT enzyme for PUFA, thereby accounting, in part at least, for the low total serum cholesterol levels one finds in children with SCD.

Estudio cinético de la reacción de hidrólisis de lecitina de soja pura en polvo con fosfolipasa A<sub>2</sub> inmovilizada

Immobilized A 2 phospholipase enzyme promotes the hydrolytic reaction of pure powder soybean lecithin releasing a mole of fatty acid from C-2 position. The main purpose of this paper was to determine the kinetic parameters of this reaction when the enzyme was adsorbed on alumina or DEAE-sephadex. The best conditions for the reaction were: temperature: 45-48oC, Ca ions concentration: 6mM, pH: 8,65. Tested conditions for substrate concentration were: 6,3; 12,7; 19 and 25 mM working in a batch type reactor and with the immobilized enzyme. The incubating time did not change the enzymatic activity. The hydrolytic activity of alumina or DEAE-sephadex adsorbed A 2 phospholipase enzyme was lower than of the soluble enzyme because the intrinsic properties are modified by immobilization. For substrate concentrations ranging between 6 and 19 mM first order kinetic velocity constants were k = 9, 88. 10 -2 min -1 and k = 1,766. 10 -1 min -1 for alumina and DEAEsephadex respectively. For the same supports but at higher substrate concentration (25mM) the zero order kinetic velocity constants were k= 1,62. 10 -3 mol.l -1 min -1 (alumina) and k = 3,58. 10 -3 mol.l -1 min -1 (DEAE-sephadex).

Isolation and characterization of two distinct forms of liver fatty acid binding protein from the rat

Liver fatty acid binding protein (L-FABP) appears to contain several different forms that may result from post-translational modification or bound ligand. To further assess this possibility, L-FABP was purified from rat liver homogenate and two putative isoforms separated using a sulfonyl column, a strong cation exchange resin. Fraction I eluted at 0.2 M NaCl, had a p I of 7.59, and following a final size exclusion step contained >98% L-FABP. Fraction II eluted at 1.0 M NaCl, had a p I of 7.59, and following a final size exclusion step contained >99% L-FABP. Both fractions contained approx. 0.15 moles of endogenous bound fatty acid per mole of protein, while L-FABP not subjected to the cation exchange step contained 0.75 moles of fatty acid per mole of protein. Fractions I and II had a greater proportion of saturated and monounsaturated fatty acids with a large reduction in polyunsaturated fatty acids compared to L-FABP not fractionated by cation exchange. Mass spectral analysis indicated the molecular mass of Fraction I was 14 315.02±0.35 Da and Fraction II was 14 315.86±0.34 Da. The peptide map for each fraction was determined by limited digestion of each fraction with either trypsin, Asp-N, or chymotrypsin to yield overlapping peptide fragments. Mass spectral analysis of these digests indicated the two proteins had identical amino acid fragments and that Cys 69 was reduced and there were no Asn to Asp exchanges. Hence, these two forms of L-FABP were not isoforms and were not the result of differences in bound fatty acid. It is proposed that these two distinct forms of rat L-FABP were structural conformers based on two alternative folding pathways.

Synthesis and performance of ester quaternary biodegradable softeners

AbstractReaction of hydroxyethylpiperazine with two moles of fatty acid, followed by quaternization with methyl chloride, methyl bromide or dimethyl sulfate, resulted in new quaternaries useful as biodegradable fabric softeners. Additional softeners were synthesized from hard tallow propane diamine by reaction with butyrolactone, followed by ethoxylation, esterification with one mole of fatty acid and quaternization.

Biophysical and biochemical alterations of renal cortical membranes in diabetic rat

The objective of this study was to determine whether streptozotocin-induced diabetes mellitus in the rat causes alterations in the lipid composition and fluidity of renal brush border membranes (BBM) and basolateral membranes (BLM). Compared to membranes of non-diabetic rats, BBM and BLM of diabetic rats contained 31% and 26%, respectively, less arachidonic acid and 36% and 46%, respectively, more linoleic acid esterfied in phospholipids. These changes were accompanied by a decrease in the average number of double bonds per mole of fatty acid, a measure of fatty acid unsaturation. In diabetic rats BLM had a higher total phospholipid/protein ratio (567 ± 20 vs. 482 ± 15 nmol/mg protein, P < 0.01), less cholesterol (369 ± 30 vs. 512 ± 34 nmol/mg protein, P < 0.01), more phosphatidylcholine (+72%) and less sphingomyelin (−22%) than did BBM. These differences were identical to those observed between BLM and BBM of non-diabetic rats. In control rats BLM was more fluid than BBM as assessed by the steady state fluorescence anisotrophy of diphenylhexatriene and by glycerol permeability. In diabetic rats the fluidity of BLM was not different from that of BBM as assessed by the steady state fluorescence anisotrophy of diphenylhexatriene whereas BLM was slightly more fluid than BBM as assessed by glycerol permeability. By both measures BLM and BBM from diabetic rats were significantly less fluid than BLM and BBM from control rats. Removal of proteins and cholesterol in sequence was accompanied by an increase in membrane fluidity in both groups. However, in no instance did the removal of proteins or cholesterol abolish the difference between the fluidity of diabetic membranes and that of control membranes. From these data we conclude that the reduction in fluidity of renal BLM and BBM in the diabetic rat is due to the change in the composition of fatty acids esterified in membrane phospholipids.

Enzymatic microdetermination of plasma and serum free fatty acids.

A simple and sensitive enzymatic method for determination of plasma and serum fatty acids (FAs) is described. The method is based on acylation of long chain FAs by a bacterial acyl-CoA synthetase (ACS) producing equivalent amounts of acyl-CoA and AMP. AMP production was measured using the coupled reaction of myokinase (MK), pyruvate kinase (PK) and lactate dehydrogenase (LDH) allowing fluorinate detection of NADH. Two moles of NAD were produced per mole of FA acylated. Concentrations of substrates and enzymes were kept as low as possible maintaining the ACS reaction as rate limiting. Addition of fat-free human serum albumin (HSA) to standards reduced initial reaction rates but did not affect end-point fluorescence levels. Triton X-100 partly counteracted the inhibition by HSA. To keep albumin concentration low, plasma or serum samples were diluted by 1:400. Duplicate measurements of plasma or serum FA concentrations between 0 and 2 mmol l-1 can then be performed on 5 microliters samples with intra- and inter-assay variation coefficients of 1.7 and 4% respectively.

Quantitative analysis of retinal glycerolipid molecular species acetylated by acetolysis.

A method for the quantitative analysis of molecular species of 1,2-diacylglycerol acetates (1,2-DGAC) containing polyunsaturated fatty acids is described. Phosphatidylethanolamine (PE) isolated from frog retina was used to test the method. PE was converted to 1,2-DGAC by acetolysis. The molecular species of the 1,2-DGAC were resolved by reverse-phase high performance liquid chromatography (HPLC), detected by UV absorption spectroscopy at 210 nm, and identified by gas-liquid chromatography (GLC) of the fatty acid methyl esters (FAME). Molar response curves were generated for each DGAC molecular species that eluted as a single entity from HPLC by determining the moles of fatty acids in the molecular species collected and the response (peak area unit) of the UV detector. Each molecular species response curve was linear from about 10 pmoles to 4-8 nmoles, allowing the slope of each curve to be used as a molar absorptivity. This method provides a means for quantification of most of the molecular species of all glycerolipid classes.

Commercial fatty acid ethoxylates as corrosion inhibitors for steel in pickling acids

Corrosion inhibitors have been prepared by ethoxylation of four commercially available unsaturated fatty acid mixtures: tall oil, soya bean oil, cotton seed oil, and linseed oil. The compounds obtained have the general formula R–COO–(CH2CH2O)n–H, where R is mainly a mixture of C17H29, C17H31, and C17H33 and n equals 20 ethylene oxide moles per mole of fatty acid. They have almost the same hydrophilic-lipophilic balance (HLB), which governs most of their surface activities, but differ in their fatty acid composition. The synthesised compounds provide satisfactory inhibition of steel in hydrochloric acid at temperatures up to 80°C. The ethoxylate of linseed oil is the most efficient inhibitor on account of its high content of linolenic acid, which has three double bonds. Polarisation measurements indicate that the additives act as mixed type inhibitors.

Transport and utilization of free fatty acids in Triatomainfestans

Triatoma infestans hemolymph has 0.31 mg/ml of free fatty acids and 2.8 mg/ml of diacylglycerols. Almost all the diacylglycerols are transported by lipophorin whereas free fatty acids are carried by lipophorin and a very high density lipoprotein. The binding of cis-parinaric acid to lipophorin was employed to specify the free fatty acid binding properties of lipophorin. Lipophorin has 10 binding sites of high affinity (3 x 10(7)) and approximately 45 binding sites of low affinity (1 x 10(6)). The relative rate of tissue incorporation of free fatty acids and diacylglycerols was measured by injecting insects with hemolymph previously labeled in both, free fatty acids and diacylglycerols. In this way, the half-life of the hemolymph free fatty acids was estimated to be about 4 min. Based on this result and taking into account the content of free fatty acids and diacylglycerols in hemolymph, the incorporation of free fatty acids, expressed in moles of fatty acids, seems to be 3.4 times higher than that of diacylglycerols. This finding can be applied to other insects.

Gel-state metastability and nature of the azeotropic points in mixtures of saturated phosphatidylcholines and fatty acids

The temperature-composition phase diagrams of dipalmitoylphosphatidylcholine (DPPC)/palmitic acid and distearoylphosphatidylcholine (DSPC)/stearic acid mixtures in excess water were recorded using high-sensitivity differential scanning calorimetry. New, slowly reversible phase transitions were found at 38° C in DPPC/palmitic acid mixtures at 0.4–0.9 mole fractions of palmitic acid and at 46° C in the DSCP/stearic acid binary. These transitions reveal gel-state metastability of the mixtures which is caused most probably by co-crystallization of the two lipids as it cannot be observed in the pure components. Both mixtures display azeotropic behavior at 2 fatty acids per 1 phospholipid. The physical reasons for such behavior have been analyzed theoretically in the framework of the Bragg-Williams and the UNIversal QUAsiChemical (UNIQUAC) approximations. This analysis shows that the azeotropic points in the phase diagrams are due to a combination of compound formation in the solid state and close to random mixing in the liquid state of the mixtures. UNIQUAC provides better fits to the experimental phase diagrams since it accounts also for the dimer-monomer character of the phospholipid/fatty acid mixtures. At fatty acid mole fractions greater than 0.65–0.7 the excess fatty acids phase separate from the compound phase. The stability of the compound phase domains at low fatty acid concentrations in relation to their possible physiological role has been discussed.

Reaction of fatty acids with 3,3′‐iminobis‐propylamine to produce soil hydrophobic agents

AbstractThe reaction between two moles of fatty acid and one of 3,3′‐iminobis‐propylamine (DPTA) is somewhat analogous to the reaction between fatty acid and diethylenetriamine (DETA) that we had reported previously, but there are significant differences. Conversion to the diamide HN(CH2CH2CH2NHCOR)2 proceeds much more rapidly but less efficiently than does the reaction of fatty acid with DETA. The former diamide is obtained in only about a 70% yield and byproducts are obtained, whereas the reaction with DETA yields the diamide almost quantitatively. Cyclization to the pyrimidine urn:x-wiley:0003021X:media:aocs0744:equation:aocs0744-math-0001is extremely slow and incomplete. The analogous cyclization of α,ω‐diamides of DETA produces high yields of imidazolines. The AOCs wet method for amine titration gave erroneous structural information when the test was applied to the diamides of DPTA, as was the case for the DETA‐diamide. The water repellency of soils treated with a homologous series of fatty iminobis‐propylamine (DPTA)‐diamides was studied, and the following observations were made: 1) the fatty DPTA‐diamides were slightly more hydrophobic than the fatty DETA‐diamides, which we ascribe to the additional methylene groups of the former; 2) hydrophobicity intensified with increasing molecular weight of the saturated fatty acids; and 3) unsaturation, as in the oleic derivative, enhanced hydrophilicity.

Expression of rat intestinal fatty acid-binding protein in Escherichia coli. Purification and comparison of ligand binding characteristics with that of Escherichia coli-derived rat liver fatty acid-binding protein.

Rat intestinal fatty acid-binding protein (I-FABP) is an abundant, 15,124-Da polypeptide found in the cytosol of small intestinal epithelial cells (enterocytes). It is homologous to rat liver fatty acid-binding protein (L-FABP), a 14,273-Da cytosolic protein which is found in enterocytes as well as hepatocytes. It is unclear why the small intestinal epithelium contains two abundant fatty acid-binding proteins. A systematic comparative analysis of the ligand binding characteristics of the two FABPs has not been reported. To undertake such a study we expressed the coding region of a full length I-FABP cDNA in Escherichia coli and purified large quantities of the protein. We also purified rat L-FABP from a similar, previously described expression system (Lowe, J. B., Strauss, A. W., and Gordon, J. I. (1984) J. Biol. Chem. 259, 12696-12704). Analysis of fatty acids associated with each of the homogeneous E. coli-derived FABPs suggested that the two proteins differed in their ligand binding specificity and capacity. All of the fatty acids associated with I-FABP were saturated while 30% of the E. coli fatty acids bound to L-FABP were unsaturated (16:1, 18:1, 18:2). We directly analyzed the ability of I- and L-FABP to bind fatty acids of different chain length and degree of saturation using a hydroxyalkoxypropyl dextran-based assay. Scatchard analysis revealed that each mole of L-FABP can bind up to 2 mol of long chain fatty acid while each mole of I-FABP can bind only 1 mole of fatty acid. L-FABP exhibited a relatively higher affinity for unsaturated fatty acids (oleate, arachidonate) than for saturated fatty acid (palmitate). By contrast, we were not able to detect a significant difference in the affinity of I-FABP for palmitate, oleate, and arachidonate. Neither protein exhibited any appreciable affinity for fatty acids whose chain length was less than C16. The observed differences in ligand affinities and capacities suggest that these proteins may have distinct roles in metabolism and/or compartmentalization of fatty acids within enterocytes.

Yeast fatty acid synthase: structure to function relationship.

The yeast fatty acid synthase is a multifunctional enzyme composed of two nonidentical subunits in an alpha 6 beta 6 complex that is active in synthesizing fatty acids. The seven catalytic activities required for fatty acid synthesis are divided between the alpha and beta subunits such that the alpha 6 beta 6 complex has six complements of each activity. It has been proposed that these are organized into six centers for fatty acid synthesis. There are different opinions regarding the operation of these centers in the alpha 6 beta 6 complex, on view being that they are functionally independent and the other proposes half-sites activity for the complex. We have attempted to distinguish between these proposals by the most direct method of active site titration, i.e., quantitation of fatty acyl product in the absence of turnover. This was accomplished by using p-nitrophenyl thioacetate and thiophenyl malonate (in place of the coenzyme A analogues) as substrates along with NADPH, thereby depriving the yeast synthase of coenzyme A required to release product as fatty acyl coenzyme A. The amount of fatty acyl product formed was quantitated by gas-liquid chromatography, as well as by direct estimation of radioactivity in the product when p-nitrophenyl thio [1-14C] acetate was used as a substrate. In both cases, a stoichiometry of close to six was found for mole of fatty acid synthesized per mole of alpha 6 beta 6 complex. This indicates that there are six functional centers for fatty acid synthesis in the multifunctional yeast alpha 6 beta 6 fatty acid synthase and that these centers operate independently.(ABSTRACT TRUNCATED AT 250 WORDS)