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Lipases represent versatile biocatalysts extensively employed in transesterification reactions for ester production. Ethyl oleate holds significance in biodiesel production, serving as a sustainable alternative to petroleum-derived diesel. In this study, our goal was to prospect lipase and assess its efficacy as a biocatalyst for ethyl oleate synthesis. For quantitative analysis, a base medium supplemented with Rhodamine B, olive oil, and Tween 80 was used. Solid-state fermentation utilized crambe seeds of varying particle sizes and humidity levels as substrates. In the synthesis of ethyl oleate, molar ratios of 1:3, 1:6, and 1:9, along with a total enzymatic activity of 60 U in n-heptane, were utilized at temperatures of 30 °C, 37 °C, and 44 °C. Reactions were conducted in a shaker at 200 rpm for 60 min. As a result, we first identified Penicillium polonicum and employed the method of solid-state fermentation using crambe seeds as a substrate to produce lipase. Our findings revealed heightened lipolytic activity (22.5 Ug -1 ) after 96 h of fermentation using crambe cake as the substrate. Optimal results were achieved with crambe seeds at a granulometry of 0.6 mm and a fermentation medium humidity of 60%. Additionally, electron microscopy suggested the immobilization of lipase in the substrate, enabling enzyme reuse for up to 4 cycles with 100% enzymatic activity. Subsequently, we conducted applicability tests of biocatalysts for ethyl oleate synthesis, optimizing parameters such as the acid/alcohol molar ratio, temperature, and reaction time. We attained 100% conversion within 30 min at 37 °C, and our results indicated that the molar ratio proportion did not significantly influence the outcome. These findings provide a methodological alternative for the utilization of biocatalysts in ethyl oleate synthesis., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Biodegradable and biobased surface active agents are renewable and environmentally friendly alternatives to petroleum derived or oleochemical surfactants. However, they are accompanied by relatively high production costs. In this study, the aim was to reduce the production costs for an innovative type of microbial biosurfactant: bolaform sophorolipids, produced by the yeast Starmerella bombicola ΔsbleΔat. A novel continuous retentostat set-up was performed whereby continuous broth microfiltration retained the biomass in the bioreactor while performing an in situ product separation of bolaform sophorolipids. Although a mean volumetric productivity of 0.56 g L -1 h -1 was achieved, it was not possible to maintain this productivity, which collapsed to almost 0 g L -1 h -1 . Therefore, two process adaptations were evaluated, a sequential batch strategy and a phosphate limitation alleviation strategy. The sequential batch set-up restored the mean volumetric productivity to 0.66 g L -1 h -1 for an additional 132 h but was again followed by a productivity decline. A similar result was obtained with the phosphate limitation alleviation strategy where a mean volumetric productivity of 0.54 g L -1 h -1 was reached, but a productivity decline was also observed. Whole genome variant analysis uncovered no evidence for genomic variations for up to 1306 h of retentostat cultivation. Untargeted metabolomics analysis identified 8-hydroxyguanosine, a biomarker for oxidative RNA damage, as a key metabolite correlating with high bolaform sophorolipid productivity. This study showcases the application of a retentostat to increase bolaform sophorolipid productivity and lays the basis of a multi-omics platform for in depth investigation of microbial biosurfactant production with S. bombicola., (Copyright © 2021. Published by Elsevier B.V.)

A highly efficient sophorolipid (SL) fermentation process using dual lipophilic substrates (DLS) was developed. Using DLS consisting of palm oil and oleic acid in the flask fermentation with SL-producing yeast Starmerella bombicola, the productivity and yield of SL improved 2.4 and 1.7 times, in comparison to when using palm olein alone. In the jar fermentation process with DLS, the SL productivity and yield of 127 g/L and 62.4% were achieved in 7 days, with the complete consumption of residual lipophilic substrates in the culture medium. This process was successfully applied to the effective conversion of waste frying oil to SL, maintaining a high SL productivity and yield of 142.8 g/L and 72% in 9 days. It is concluded that the newly developed fermentation process with DLS can be useful for the industrial production of SL from renewable biological sources, especially waste frying oils., (© The Author(s) 2021. Published by Oxford University Press on behalf of Japan Society for Bioscience, Biotechnology, and Agrochemistry.)

The hydrolysis properties of lipase in castor was evaluated using two different substrate forms (tripalmitic glycerides and trioleic glycerides) to catalyze the reaction under different operational conditions. RcLipase was obtained from castor seeds and results show that RcLipase is a conservative serine lipase with a conserved catalytic center (SDH) and a conserved pentapeptide (GXSXG). This enzyme exhibited the greatest activity and tolerance to chloroform and toluene when it was expressed in Pichia pastoris GS115 at 40 ℃ and pH 8.0. Zn and Cu ions exerted obvious inhibitory effects on the enzyme, and displayed good hydrolytic activity for long-chain natural and synthetic lipids. HPLC analysis showed that this enzyme has 1,3 regioselectivity when glycerol tripalmitate and oleic acid are used as substrates. The fatty acid composition in the reaction product was 21.3% oleic acid and 79.1% sn-2 palmitic acid.

One of the reasons hindering large-scale application of sophorolipids (SLs) is high production cost. In this study, six recombinant strains of Starmerella bombicola, sbEG1, sbEG2, sbCBH1, sbCBH1-2, sbBGL1, and sbCBH2 expressing cellulase genes eg1, eg2, cbh, cbh1-2, bgl1, and cbh2 from Penicillium oxalicum were respectively constructed. Four strains showed cellulase activities and were co-cultivated in fermentation media containing 2% glucose, 1% Regenerated Amorphous Cellulose (RAC), 2% glucose, and 1% RAC, respectively. After 7 days' cultivation, concentration of SLs in medium with 1% RAC (g/L) reached 1.879 g/L. When 2% glucose and 1% of RAC were both contained, the titer of SLs increased by 39.5% than that of control strain and increased by 68.8% than that in the medium with only 2% glucose. Results demonstrated that cellulase genes from filamentous fungi in S. bombicola can function to degrade lignocellulosic cellulose to produce SLs.

To enhance specific or total sophorolipids (SLs) production by Starmerella bombicola for specific application, mutant library consisting of 106 mutants from 7 batches was constructed via atmospheric and room-temperature plasma (ARTP). When compared to the wild strain, 11, 36 and 12 mutants performed increases over 30% in lactonic, acidic or total SLs production. Genetic stability investigation showed that 8, 7, and 4 mutants could maintain the improved SLs production capacity. Mutants of A6-9 and A2-8 were selected out for enhanced specific SLs and total SLs production in fed-batch cultivation in flask. Without optimization, A6-9 obtained the highest reported lactonic SLs production of 51.95 g/l and A2-8 performed comparable acidic and total SLs production of 68.75 g/l and 100.33 g/l with all the reported stains. The structural composition of the obtained SLs was analyzed by HPLC and LC/MS, and the results confirmed the enhancement of SLs and certain SL components. These mutants would be important in industrial applications because the production and purification costs of SLs could be greatly reduced. Besides, the acquisition of these mutants also provided materials for the investigation of regulation mechanism of SLs biosynthesis for further genetic engineering of S. bombicola. Furthermore, critical micelle concentration (CMC), minimum surface tension (ST min ) and hydrophilic-lipophilic balance (HLB) of the SLs obtained from the wild and mutant strains were also examined and compared. These results demonstrated the feasibility of obtaining SLs with different properties from different strains and the high efficiency of mutation breeding of S. bombicola by ARTP.

Starmerella bombicola is a non-conventional yeast commercially used as a microbial cell factory for sophorolipid production. Sophorolipids are glycolipid biosurfactants composed of a glucose disaccharide sophorose and a fatty acid. In de novo sophorolipid synthesis, the fatty acid moiety is derived from the fatty acid synthesis (FAS) complex; therefore, the yeast's lipid metabolism plays a crucial role in sophorolipid biosynthesis. As a fatty acid precursor, citric acid is a key primary metabolite that connects carbohydrate and lipid metabolism, and in S. bombicola, it also has a regulatory effect on sophorolipid composition and productivity. We aimed to identify the mitochondrial transporters involved in citrate shuttling and the ATP citrate lyase (Acl), the enzyme that converts citric acid into acetyl-CoA. Subsequently, we studied their role in the citric acid shuttle and glycolipid synthesis and the potential of citrate metabolism as a genetic manipulation target for increased glycolipid synthesis. Bioinformatics analyses predicted 32 mitochondrial carriers of which two were identified as citrate transporters, named SbCtp1 and SbYhm2. Deletion of these mitochondrial carriers led to a lesser sophorolipid yield and a shift in the lactonic/acidic sophorolipid ratio. However, only the knockout of SbYhm2 caused a decrease of citric and an increase of malic acid extracellular concentrations. Additionally, deletion of SbAcl1 had a negative effect on S. bombicola's specific growth rate and sophorolipid synthesis and contributed to extra- and intracellular citric acid accumulation. Unexpectedly, SbAcl1 overexpression also decreased glycolipid production.Key Points• Starmerella bombicola is an industrially relevant microbial cell factory for biosurfactant production.• There are 32 predicted mitochondrial carriers in S. bombicola.• Citrate mitochondrial carriers SbYhm2 and SbCtp1 are essential for glycolipid synthesis in S. bombicola.• Deletion of SbAcl1 negatively affects growth and sophorolipid production in S. bombicola. Graphical abstract.

Valproic acid or valproate (VPA) is an anticonvulsive drug used for treatments of epilepsy, bipolar disorder, and migraine headaches. VPA is also an epigenetic modulator, inhibiting histone deacetylase, and it has been subjected to clinical study for cancer treatment. During the investigation of VPA on a metabolite profile in a fungus, we found that VPA has significant effects on the production of some fatty acids. Further exploration of VPA on fatty acid profiles of microorganisms, fungi, yeast, and bacteria, as well as representative gut microbiome, revealed that VPA could enhance or reduce the production of some fatty acids. VPA was found to induce the production of trans-9-elaidic acid, a fatty acid that was previously reported to have cellular effects in human macrophages. VPA could also inhibit the production of some polyketides produced by a model fungus. The present work suggests that the induction or inhibition of fatty acid biosynthesis by VPA (100 µM) in gut microbiome could give effects to patients treated with VPA because high doses of VPA oral administration (up to 600 mg to 900 mg) are used by patients; the concentration of VPA in the human gut may reach a concentration of 100 µM, which may give effects to gut microorganisms.

Petroselinic acid (18:1Δ 6 ), a monounsaturated cis Δ-6 fatty acid, has many prospective applications in functional foods and for the nutraceutical and pharmaceutical industries. Up to 80% of petroselinic acid has been found in the oil from fruits of coriander ( Coriandrum sativum L.), which make it an ideal source for investigating the biosynthesis of petroselinic acid. A coriander acyl-acyl carrier protein desaturase was identified to be involved in its biosynthesis more than two decades ago, but since then little further progress in this area has been reported. In this study, the fatty acid profiles of coriander fruits at six developmental stages were analyzed. Fruit samples from three developmental stages with rapid accumulation of petroselinic acid were used for RNA sequencing using the Illumina Hiseq4000 platform. The transcriptome analysis presented 93 323 nonredundant unigenes and 8545 differentially expressed genes. Functional annotation and combined gene expression data revealed candidate genes potentially involved in petroselinic acid biosynthesis and its incorporation into triacylglycerols. Tissue-specific examination of q-PCR validation further suggested that ACPD1/3 , KAS I-1 , FATB-1/3 , and DGAT2 may be highly involved. Bioinformatic analysis of CsFATB and CsDGAT2 identified their putative key amino acids or functional motifs. These results provide a molecular foundation for petroselinic acid biosynthesis in coriander fruit and facilitate its genetic engineering in other hosts.

Starmerella bombicola very efficiently produces the secondary metabolites sophorolipids (SLs). Their biosynthesis is not-growth associated and highly upregulated in the stationary phase. Despite high industrial and academic interest, the underlying regulation of SL biosynthesis remains unknown. In this paper, potential regulation of SL biosynthesis through the telomere positioning effect (TPE) was investigated, as the SL gene cluster is located adjacent to a telomere. An additional copy of this gene cluster was introduced elsewhere in the genome to investigate if this results in a decoy of regulation. Indeed, for the new strain, the onset of SL production was shifted to the exponential phase. This result was confirmed by RT-qPCR analysis. The TPE effect was further investigated by developing and applying a suitable reporter system for this non-conventional yeast, enabling non-biased comparison of gene expression between the subtelomeric CYP52M1- and the URA3 locus. This was done with a constitutive endogenous promotor (pGAPD) and one of the endogenous promotors of the SL biosynthetic gene cluster (pCYP52M1). A clear positioning effect was observed for both promotors with significantly higher GFP expression levels at the URA3 locus. No clear GFP upregulation was observed in the stationary phase for any of the new strains., (© FEMS 2020.)

Sophorolipids (SLs) are surface-active molecules produced by the non-pathogenic yeast Starmerella bombicola CGMCC 1576. Several genes involved in the synthesis of SLs have been identified. However, the regulation mechanism of the synthesis pathway for SLs has not been investigated. We recently discovered a protein in S. bombicola, which is structurally related to Yarrowia lipolytica YlBro1. To identify the function of the protein SbBro1 in S. bombicola, the deletion, overexpression, and complementary mutant strains were constructed. We found that the deletion mutant no longer produced SLs. Transcriptome analysis indicated that the expression levels of the key enzyme genes of SLs biosynthetic pathway were significantly down-regulated in the Δbro1, especially the expression level of cyp52m1 encoding the first rate-limiting enzyme in SL synthesis pathway was down-regulated 13-folds and the expression of fatty acid β-oxidation-related enzymes was also down-regulated. This study can give insight into the regulation of SL synthesis.

Phospholipids, the most abundant membrane lipid components, are crucial in maintaining membrane structures and homeostasis for biofunctions. As a structurally diverse and tightly regulated system involved in multiple organelles, phospholipid metabolism is complicated to manipulate. Thus, repurposing phospholipids for lipid-derived chemical production remains unexplored. Herein, we develop a Saccharomyces cerevisiae platform for de novo production of oleoylethanolamide, a phospholipid derivative with promising pharmacological applications in ameliorating lipid dysfunction and neurobehavioral symptoms. Through deregulation of phospholipid metabolism, screening of biosynthetic enzymes, engineering of subcellular trafficking and process optimization, we could produce oleoylethanolamide at a titer of 8,115.7 µg l -1 and a yield on glucose of 405.8 µg g -1 . Our work provides a proof-of-concept study for systemically repurposing phospholipid metabolism for conversion towards value-added biological chemicals, and this multi-faceted framework may shed light on tailoring phospholipid metabolism in other microbial hosts.

Sophorolipids (SLs), mainly synthesized by yeasts, were a sort of biosurfactant with the highest fermentation level at present. In recent years, SLs have drawn extensive attention for their excellent physiochemical properties and physiological activities. Besides, issues such as economics, sustainability, and use of renewable resources also stimulate the shift from chemical surfactants towards green or microbial-derived biosurfactants. SLs' large-scale production and application were restricted by the relatively high production costs. Currently, waste streams from agriculture, food and oil refining industries, etc., have been exploited as low-cost renewable substrates for SL production. Advanced cultivation method, uncommonly used substrates, and new genetically modified SL-producing mutants were also designed and applied to improve the productivity or the special properties of SLs. In this review, a systematic and detailed description of primary and secondary metabolism pathways involved in SL biosynthesis was summarized firstly. Furthermore, based on the pathways of SL biosynthesis from different carbon substrates, we reviewed the current knowledge and advances in the exploration of cost-effective and infrequently used hydrophilic and hydrophobic substrates for large or specialized SL production.

To decrease our dependency for the diminishing source of fossils resources, bio-based alternatives are being explored for the synthesis of commodity and high-value molecules. One example in this ecological initiative is the microbial production of the biosurfactant sophorolipids by the yeast Starmerella bombicola. Sophorolipids are surface-active molecules mainly used as household and laundry detergents. Because S. bombicola is able to produce high titers of sophorolipids, the yeast is also used to increase the portfolio of lipophilic compounds through strain engineering. Here, the one-step microbial production of hydroxy fatty acids by S. bombicola was accomplished by the selective blockage of three catabolic pathways through metabolic engineering. Successful production of 17.39 g/l (ω-1) linked hydroxy fatty acids was obtained by the successive blockage of the sophorolipid biosynthesis, the β-oxidation and the ω-oxidation pathways. Minor contamination of dicarboxylic acids and fatty aldehydes were successfully removed using flash chromatography. This way, S. bombicola was further expanded into a flexible production platform of economical relevant compounds in the chemical, food and cosmetic industries., (© FEMS 2019.)

Polyacetylenes (PAs) are bioactive, specialized plant defense compounds produced by some species in the eudicot clade campanulids. Early steps of PA biosynthesis are catalyzed by Fatty Acid Desaturase 2 ( FAD2 ). Canonical FAD2s catalyze desaturation, but divergent forms can catalyze hydroxylation, conjugation, acetylenation, and epoxygenation. These alternate reactions give rise to valuable unusual fatty acids, including the precursors to PAs. The extreme functional diversity of FAD2 enzymes and the origin of PA biosynthesis are poorly understood from an evolutionary perspective. We focus here on the evolution of the FAD2 gene family. We uncovered a core eudicot-wide gene duplication event giving rise to two lineages: FAD2-α and FAD2-β. Independent neofunctionalizations in both lineages have resulted in functionally diverse FAD2-LIKEs involved in unusual fatty acid biosynthesis. We found significantly accelerated rates of molecular evolution in FAD2-LIKEs and use this metric to provide a list of uncharacterized candidates for further exploration of FAD2 functional diversity. FAD2-α has expanded extensively in Asterales and Apiales, two main clades of campanulids, by ancient gene duplications. Here, we detected positive selection in both Asterales and Apiales lineages, which may have enabled the evolution of PA metabolism in campanulids. Together, these findings also imply that yet uncharacterized FAD2-α copies are involved in later steps of PA biosynthesis. This work establishes a robust phylogenetic framework in which to interpret functional data and to direct future research into the origin and evolution of PA metabolism., (© 2019 American Society of Plant Biologists. All Rights Reserved.)

Both strain engineering and process optimization are intensively studied in microbial biosurfactant literature. However, screening of multiple strains and/or medium components in parallel is a very labor-intensive and timely process, considering the only applied technique nowadays is evaluation through shake flask and/or bioreactor experiments. Therefore, in this work, the development, optimization, and application of a more throughput technique-based on 24-deep well plates-are described for a new Starmerella bombicola strain producing bolaform sophorolipids. To develop an optimal setup, the influence of plate position and culture volume and the type of sandwich cover was investigated. Optimal parameters, which did not result in significant differences compared with shake flask experiments concerning growth, glucose consumption, and production of novel sophorolipids, were defined and validated. Next, the new method was applied to evaluate the influence of the use of alternative (commercial) nitrogen sources in comparison with the yeast extract currently applied in the production medium, aiming to increase production efficiency. Self-made yeast extracts from S. bombicola cells were also included to evaluate possible recycling of cells after fermentation. In conclusion, the designed method enabled the efficient and successful comparison of ten different nitrogen sources in varying concentrations (1, 4, and 10 g/L) on bola sophorolipid production, which can now also be performed for other parameters important for growth and/or glycolipid production.

Oleoylethanolamide (OEA), a fatty acid ethanolamide (FAE), is a lipid mediator that controls food intake and lipid metabolism. Accumulating data imply the importance of intestinal OEA in controlling satiety in addition to gastrointestinal peptide hormones. Although the biochemical pathway of FAE production has been illustrated, the enzymes responsible for the cleavage of OEA from its precursor N-acyl-phosphatidylethanolamine (NAPE) must be identified among reported candidates in the gut. In this study, we assessed the involvement of NAPE-specific phospholipase D (NAPE-PLD), which can directly release FAEs from NAPE, in intestinal OEA synthesis and lipid metabolism. Clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPER-associated protein 9 (Cas9)-mediated deletion of the NAPE-PLD gene in intestinal epithelial-like Caco-2 cells reduced OEA levels, regardless of their differentiation states. Transcriptome analysis revealed that deletion of NAPE-PLD activates a transcriptional program for nutrient transportation, including lipids and lipoproteins, and inactivates cell-cycle or mitosis-related genes in Caco-2 cells. In addition, the basolateral secretion of lipoproteins was increased in NAPE-PLD-deleted cells although lipoprotein size was not affected. By contrast, cellular lipid levels were reduced in NAPE-PLD-deleted cells. Overall, these results indicate that NAPE-PLD plays important roles in OEA synthesis and fat absorption by regulating lipoprotein production in the intestinal epithelial cells.-Igarashi, M., Watanabe, K., Tsuduki, T., Kimura, I., Kubota, N. NAPE-PLD controls OEA synthesis and fat absorption by regulating lipoprotein synthesis in an in vitro model of intestinal epithelial cells.

In this review, we focus on one of the most important microbial producers of biosurfactants, Starmerella bombicola. Emphasis is laid on the discovery, taxonomy, habitat, cellular characteristics, biochemistry and genetics of this non-pathogenic yeast. Biosurfactants are natural surface-active compounds produced by several types of microorganisms and have been considered an interesting alternative to synthetic surfactants. The sophorolipids produced by S. bombicola are promising biosurfactants, with application potential in food, pharmaceutical, cosmetic and cleaning industries. The fundamental knowledge described in this review is of crucial interest to optimize production of these promising compounds. Furthermore, it can be translated to produce novel non-native bioactive molecules with S. bombicola, and to deepen fundamental knowledge on other non-conventional yeast species and in the end to broaden their application potential as well.

10-oxo-trans-11-octadecenoic acid (KetoC) and 10-hydroxy-cis-12-octadecenoic acid (HYA) are long-chain fatty acids generated from linoleic acid by the gut lactic acid bacterium Lactobacillus plantarum. These fatty acids have been reported to have anti-inflammatory activity in the intestine. However, little is known about their effects in the brain. In this study, we aimed to investigate the effects of these fatty acids on lipopolysaccharide (LPS)-induced inflammatory processes in mouse microglial cells (BV-2 cells). KetoC and HYA inhibited LPS-induced nitric oxide (NO) production and suppressed the expression of inducible NO synthase in BV-2 cells. NO changes in these inhibitory effects were observed with AH7614, a G-protein coupled receptor 120 antagonist, or the peroxisome proliferator-activated receptors antagonists, GW6471 and GW9662. In addition, KetoC and HYA did not inhibit translocation of p65, a subunit of NF-κB, or IκB degradation. Similarly, no effect on p38 or JNK phosphorylation was observed. However, KetoC and HYA were found to inhibit ERK phosphorylation induced by LPS, suggesting that these fatty acids may exert their anti-inflammatory effects through the inhibition of ERK activation in microglial cells., (Copyright © 2018 The Authors. Production and hosting by Elsevier B.V. All rights reserved.)

In this study, aiming to improve the economic feasibility of acetone-butanol-ethanol (ABE) fermentation process, generate valuable products and extend the product chain, esterification catalyzed by Candida sp. 99-125 cells was hybrid with the ABE fermentation-gas-stripping integration system. The gas-stripping condensate that contained concentrated ABE products was directly used for esterification without the participation of toxic organic solvents. Full-cell catalysis temperature and the cell dosage rate on oleate production were evaluated and optimized in the esterification process. Under the optimized conditions (35 °C, 8% of cells), ~ 68% of butyl oleate and ~ 12% of ethyl oleate were obtained after 4 h of esterification. The Candida sp. 99-125 cells were able to be reused for at least four cycles. The novel cascade process showed environmental benefits, which also showed promising in improving the economic feasibility of the conventional ABE fermentation process.

Various yeasts, both conventional and exotic ones, are known to produce compounds useful to mankind. Ethanol is the most known of these compounds, but more complex molecules such as amphiphilic biosurfactants can also be derived from eukaryotic microorganisms at an industrially and commercially relevant scale. Among them, glycolipids are the most promising, due to their attractive properties and high product titers. Many of these compounds can be considered as secondary metabolites with a specific function for the host. Hence, a dedicated biosynthetic process enables regulation and combines pathways delivering the lipidic moiety and the hydrophilic carbohydrate part of the glycolipid. In this Review, we will discuss the biosynthetic and regulatory aspects of the yeast-derived sophorolipids, mannosylerythritol lipids, and cellobiose lipids, with special emphasis on the relation between glycolipid synthesis and the general lipid metabolism., (© 2017 Federation of European Biochemical Societies.)

Brown adipose tissue (BAT) and beige adipose tissue combust fuels for heat production in adult humans, and so constitute an appealing target for the treatment of metabolic disorders such as obesity, diabetes and hyperlipidemia. Cold exposure can enhance energy expenditure by activating BAT, and it has been shown to improve nutrient metabolism. These therapies, however, are time consuming and uncomfortable, demonstrating the need for pharmacological interventions. Recently, lipids have been identified that are released from tissues and act locally or systemically to promote insulin sensitivity and glucose tolerance; as a class, these lipids are referred to as 'lipokines'. Because BAT is a specialized metabolic tissue that takes up and burns lipids and is linked to systemic metabolic homeostasis, we hypothesized that there might be thermogenic lipokines that activate BAT in response to cold. Here we show that the lipid 12,13-dihydroxy-9Z-octadecenoic acid (12,13-diHOME) is a stimulator of BAT activity, and that its levels are negatively correlated with body-mass index and insulin sensitivity. Using a global lipidomic analysis, we found that 12,13-diHOME was increased in the circulation of humans and mice exposed to cold. Furthermore, we found that the enzymes that produce 12,13-diHOME were uniquely induced in BAT by cold stimulation. The injection of 12,13-diHOME acutely activated BAT fuel uptake and enhanced cold tolerance, which resulted in decreased levels of serum triglycerides. Mechanistically, 12,13-diHOME increased fatty acid (FA) uptake into brown adipocytes by promoting the translocation of the FA transporters FATP1 and CD36 to the cell membrane. These data suggest that 12,13-diHOME, or a functional analog, could be developed as a treatment for metabolic disorders.

The chemical modification of anthocyanins (water-soluble pigments) into more lipophilic compounds is very important to expand their application in the food, medical and cosmetic industries. In this work, the synthesis of a pure malvidin-3-glucoside-oleic acid ester derivative was achieved by enzymatic catalysis. This approach allowed us to synthesize a novel compound, malvidin-3-O-(6''-oleoyl)glucoside (Mv3glc-OA), which was structurally characterized by mass spectrometry and for the first time by NMR spectroscopy. The enzymatic reaction revealed to be regioselective giving only one ester product. Antioxidant features of the malvidin-3-glucoside lipophilic derivative by means of DPPH, FRAP and lipid peroxidation assays were assessed, which confirmed that the structural modification of the genuine malvidin-3-glucoside into a more lipophilic compound did not compromise its antioxidant potential and protected more effectively a lipidic substrate from oxidation, which is an important insight for future technological applications.

The details of plant lipid metabolism are relatively well known but the regulation of fatty acid production at the protein level is still not understood. Hence this study explores the importance of phosphorylation as a mechanism to control the activity of fatty acid biosynthetic enzymes using low and high oleic acid mesocarps of oil palm fruit (Elaeis guineensis variety of Tenera). Adaptation of neutral loss-triggered tandem mass spectrometry and selected reaction monitoring to detect the neutral loss of phosphoric acid successfully found several phosphoamino acid-containing peptides. These peptides corresponded to the peptides from acetyl-CoA carboxylase and 3-enoyl-acyl carrier protein reductase as identified by their precursor ion masses. These findings suggest that these enzymes were phosphorylated at 20th week after anthesis. Phosphorylation could have reduce their activities towards the end of fatty acid biosynthesis at ripening stage. Implication of phosphorylation in the regulation of fatty acid biosynthesis at protein level has never been reported.

Seed oil composed of wax esters with long-chain monoenoic acyl moieties represents a high-value commodity for industry. Such plant-derived sperm oil-like liquid wax esters are biodegradable and can have excellent properties for lubrication. In addition, wax ester oil may represent a superior substrate for biodiesel production. In this study, we demonstrate that the low-input oil seed crop Camelina sativa can serve as a biotechnological platform for environmentally benign wax ester production. Two biosynthetic steps catalysed by a fatty alcohol-forming acyl-CoA reductase (FAR) and a wax ester synthase (WS) are sufficient to achieve wax ester accumulation from acyl-CoA substrates. To produce plant-derived sperm oil-like liquid wax esters, the WS from Mus musculus (MmWS) or Simmondsia chinensis (ScWS) were expressed in combination with the FAR from Mus musculus (MmFAR1) or Marinobacter aquaeolei (MaFAR) in seeds of Arabidopsis thaliana and Camelina sativa. The three analysed enzyme combinations Oleo3:mCherry:MmFAR1∆c/Oleo3:EYFP:MmWS, Oleo3:mCherry:MmFAR1∆c/ScWS and MaFAR/ScWS showed differences in the wax ester molecular species profiles and overall biosynthetic performance. By expressing MaFAR/ScWS in Arabidopsis or Camelina up to 59% or 21% of the seed oil TAGs were replaced by wax esters, respectively. This combination also yielded wax ester molecular species with highest content of monounsaturated acyl moieties. Expression of the enzyme combinations in the Arabidopsis fae1 fad2 mutant background high in oleic acid resulted in wax ester accumulation enriched in oleyl oleate (18:1/18:1 > 60%), suggesting that similar values may be obtained with a Camelina high oleic acid line., (© 2015 Society for Experimental Biology, Association of Applied Biologists and John Wiley & Sons Ltd.)

Linoleate 13-hydratase from Lactobacillus acidophilus LMG 11470 converted linoleic acid to hydroxyl fatty acid, which was identified as 13S-hydroxy-9(Z)-octadecenoic acid (13-HOD) by GC-MS and NMR. The expression of linoleate 13-hydratase gene in Escherichia coli was maximized by using pACYC plasmid and super optimal broth with catabolite repression (SOC) medium containing 40mM Mg(2+). To optimize induction conditions, recombinant cells were cultivated at 37°C, 1mM isopropyl-β-d-thiogalactopyranoside was added at 2h, and the culture was further incubated at 16°C for 18h. Recombinant cells expressing linoleate 13-hydratase from L. acidophilus were obtained under the optimized expression conditions and used for 13-HOD production from linoleic acid. The optimal reaction conditions were pH 6.0, 40°C, 0.25% (v/v) Tween 40, 25gl(-1) cells, and 100gl(-1) linoleic acid, and under these conditions, whole recombinant cells produced 79gl(-1) 13-HOD for 3h with a conversion yield of 79% (w/w), a volumetric productivity of 26.3gl(-1)h(-1), and a specific productivity of 1.05g g-cells(-1)h(-1). To the best of our knowledge, the recombinant cells produced hydroxy fatty acid with the highest concentration and productivity reported so far., (Crown Copyright © 2015. Published by Elsevier B.V. All rights reserved.)

Fatty acid oxygenases are often characterized by steric analysis of their hydroxy or hydroperoxy metabolites. Chiral phase-HPLC (CP-HPLC) can be used to separate enantiomeric hydroperoxyoctadecenoic acids. This method is based on analysis of seven octadecenoic fatty acids with double bonds at positions 6Z to 13Z, which were oxidized to hydroperoxides by photooxidation. A stationary phase, Reprosil Chiral NR, was found to resolve these hydroperoxy fatty acids with 1-hydroperoxy-2-propene and with 3-hydroperoxy-1-propene elements so that the S hydroperoxy fatty acids consistently eluted before the R stereoisomers. The chiral selector has not been disclosed, but it is described as an aromatic chiral phase with π-donor and π-acceptor groups of Pirkle type. The MS(3) spectra of the hydroperoxides showed characteristic fragments, which were influenced by the distance between the hydroperoxy and the carboxyl groups and the relative position of the double bond. Octadecenoic fatty acids can be oxidized by fungal and bacterial dioxygenases to hydroperoxides with cis or trans double bond configuration. Steric analysis of the hydroperoxy metabolites can be performed by this method, and it can also be used for preparative purposes.

Candida antarctica Lipase B was successfully immobilized on magnetite (Fe3O4) nanoparticles functionalized with chitosan and glutaraldehyde. The obtained magnetic catalyst was characterized and its performance was evaluated in solvent-free synthesis of ethyl oleate at room temperature. The performance of this biocatalyst was compared with the commercial Novozym 435, as a tool to estimate the efficiency of immobilization. It was found that using 33 mg of the biocatalyst it was possible to reach almost the same activity that was obtained using 12 mg of Novozym 435. Furthermore, this new biocatalyst presents the advantages of not being degraded by short alcohols, being easily recovered from the reaction media by magnetic decantation, and low fabrication cost. The possibility of reutilization was also studied, keeping a significant activity up to eight cycles. A special sampling protocol was also developed for the multiphasic reaction system, to assure accurate results. This novel biocatalyst is an interesting alternative for potential industrial applications, considering the above-mentioned advantages.

The reaction of transesterification between oils (e.g., olive oil) and ascorbic acid in polar anhydrous media (e.g., tert-amyl alcohol) catalyzed by immobilized lipases for the preparation of natural liposoluble antioxidants (e.g., ascorbyl oleate) was studied. Three commercial lipases were tested: Candida antarctica B lipase (CALB), Thermomyces lanuginosus lipase (TLL) and Rhizomucor miehei lipase (RML). Each lipase was immobilized by three different protocols: hydrophobic adsorption, anionic exchange and multipoint covalent attachment. The highest synthetic yields were obtained with CALB adsorbed on hydrophobic supports (e.g., the commercial derivative Novozym 435). The rates and yields of the synthesis of ascorbyl oleate were higher when using the solvent dried with molecular sieves, at high temperatures (e.g. 45°C) and with a small excess of oil (2 mol of oil per mol of ascorbic acid). The coating of CALB derivatives with polyethyleneimine (PEI) improved its catalytic behavior and allowed the achievement of yields of up to 80% of ascorbyl oleate in less than 24h. CALB adsorbed on a hydrophobic support and coated with PEI was 2-fold more stable than a non-coated derivative and one hundred-fold more stable than the best TLL derivative. The best CALB derivative exhibited a half-life of 3 days at 75°C in fully anhydrous media, and this derivative maintained full activity after 28 days at 45°C in dried tert-amyl alcohol., (Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.)

Excessive intake of dietary fats leads to diminished brain dopaminergic function. It has been proposed that dopamine deficiency exacerbates obesity by provoking compensatory overfeeding as one way to restore reward sensitivity. However, the physiological mechanisms linking prolonged high-fat intake to dopamine deficiency remain elusive. We show that administering oleoylethanolamine, a gastrointestinal lipid messenger whose synthesis is suppressed after prolonged high-fat exposure, is sufficient to restore gut-stimulated dopamine release in high-fat-fed mice. Administering oleoylethanolamine to high-fat-fed mice also eliminated motivation deficits during flavorless intragastric feeding and increased oral intake of low-fat emulsions. Our findings suggest that high-fat-induced gastrointestinal dysfunctions play a key role in dopamine deficiency and that restoring gut-generated lipid signaling may increase the reward value of less palatable, yet healthier, foods.

7,10-Dihydroxy-8(E)-octadecenoic acid (DOD), one of hydroxy fatty acids, was successfully produced from oleic acid and natural vegetable oils containing oleic acid by a bacterial strain Pseudomonas aeruginosa (PR3). However, biological properties of DOD remained unknown so far. In this study, as a trial to determine the biological properties of DOD molecule, antibacterial activities of DOD against plant pathogenic bacteria were determined qualitatively and quantitatively. DOD presented strong antibacterial activities against all the bacterial strains tested with MIC value being in the range of 125-1000μg/ml and there was no sensitivity preference detected between Gram-positive and Gram-negative strains., (Copyright © 2013 Elsevier Inc. All rights reserved.)

Lactobacillus hammesii converts linoleic acid into an antifungal hydroxy fatty acid. High speed counter-current chromatography (HSCCC) using a hexane/ethyl acetate/methanol/water solvent system [3.5:1.5:3:2 (v/v/v/v)] allowed isolation of the antifungal hydroxy fatty acid. A method was developed for characterization of antifungal hydroxy fatty acids using normal phase liquid chromatography combined with atmospheric pressure photoionization-tandem mass spectrometry (LC/APPI-MS/MS). The position of unsaturations and hydroxyl groups was determined directly from crude lipid extracts and their hydroxylated derivatives. The antifungal compounds were identified as a racemic mixture of 10-hydroxy-cis-12-octadecenoic and 10-hydroxy-trans-12-octadecenoic acid. Additionally, HSCCC and LC/APPI-MS/MS methods were used to elucidate the pathway of conversion of linoleic acid by Lactobacillus sanfranciscensis , Lactobacillus plantarum , and L. hammesii to hydroxy fatty acids and conjugated linoleic acid. This study links previously reported 10-hydroxy-12-octadecenoic acid producing Lactobacillus strains to antifungal activities.

Stroke-prone spontaneously hypertensive rats (SHRSP) are utilized as models for study of the pathogenesis of not only stroke and cardiovascular disorders but also atherosclerosis and metabolic syndrome. Basic information on the profiles of fatty acids and lipid classes in the liver is indispensable to use SHRSP as a model of disorder of lipid metabolism; nevertheless, detailed information on the metabolism of triacylglycerols (TAGs) and fatty acids in the liver of SHRSP is lacking. This study aimed to characterize profiles of lipid classes and fatty acids and to explore the mechanism underlying the characteristic alterations in metabolism of TAGs and fatty acids in the liver of SHRSP, in comparison with spontaneously hypertensive rats (SHR). The characteristic changes observed in SHRSP were (1) markedly lower hepatic TAG contents; (2) altered expressions of genes encoding three enzymes responsible for the control of TAG level, namely, adipose triglyceride lipase (for TAG degradation; up-regulated), carnitine palmitoyltransferase 1a (for fatty acid β-oxidation; up-regulated) and long-chain acyl-CoA synthetase 3 (for glycerolipid synthesis; down-regulated); (3) evidently lower contents and proportions of monounsaturated fatty acids, in particular cis-vaccenic acid (18:1n-7), in the liver and serum; and (4) down-regulation of palmitoleoyl-CoA chain elongase, which is necessary for the biosynthesis of 18:1n-7, in the liver. From the above observations, we concluded that there are significant differences in profiles of lipid classes and fatty acids between SHRSP and SHR, and that altered characteristics in SHRSP are likely responsible for increases in TAG hydrolysis and β-oxidation, and decreases in TAG synthesis and 18:1n-7 synthesis.

Lipase-catalyzed ascorbyl oleate synthesis is eco-friendly and selective way of production of liposoluble biocompatible antioxidants, but still not present on an industrial level due to the high biocatalyst costs. In this study, response surface methodology was applied in order to estimate influence of individual experimental factors, identify interactions among them, and to determine optimum conditions for enzymatic synthesis of ascorbyl oleate in acetone, in terms of limiting substrate conversion, product yield, and yield per mass of consumed enzyme. As a biocatalyst, commercial immobilized preparation of lipase B from Candida antarctica, Novozym 435, was used. In order to develop cost-effective process, at reaction conditions at which maximum amount of product per mass of biocatalyst was produced (60°C, 0.018 % (v/v) of water, 0.135 M of vitamin C, substrates molar ratio 1:8, and 0.2 % (w/v) of lipase), possibilities for further increase of ester yield were investigated. Addition of molecular sieves at 4(th) hour of reaction enabled increase of yield from 16.7 mmol g⁻¹ to 19.3 mmol g⁻¹. Operational stability study revealed that after ten reaction cycles enzyme retained 48 % of its initial activity. Optimized synthesis with well-timed molecular sieves addition and repeated use of lipase provided production of 153 mmol per gram of enzyme. Further improvement of productivity was achieved using procedure for the enzyme reactivation.

Elevated hepatic expression of fatty acid elongase-5 (Elovl5) induces FoxO1 phosphorylation, lowers FoxO1 nuclear content, and suppresses expression of genes involved in gluconeogenesis (GNG). In this report, we define the molecular and metabolic basis of Elovl5 control of FoxO1 phosphorylation. Adenoviral-mediated (Ad-Elovl5) induction of hepatic Elovl5 in diet-induced obese, glucose-intolerant mice and HepG2 cells increased the phosphorylation of Akt2-S(473) [mammalian target of rapamycin complex-2 (mTORC2) site], but not Akt2-T(308) (PDK1 site). The Akt2 inhibitor Akti1/2 blocked Elovl5 induction of FoxO1-S(256) phosphorylation in HepG2 cells. Elevated Elovl5 activity in liver and HepG2 cells induced rictor mRNA, rictor protein, and rictor-mTOR interaction, whereas rictor knockdown (siRNA) attenuated Elovl5 induction of Akt2-S(473) and FoxO1-S(256) phosphorylation in HepG2 cells. FA analysis revealed that the abundance of cis-vaccenic acid (18:1,n-7) was increased in livers of obese mice and HepG2 cells following Ad-Elovl5 infection. Treating HepG2 cells with Elovl5 substrates established that palmitoleic acid (16:1,n-7), but not γ-linolenic acid (18:3,n-6), induced rictor protein, Akt-S(473), and FoxO1-S(256) phosphorylation. Inhibition of FA elongation blocked 16:1,n-7 but not 18:1,n-7 induction of rictor protein and Akt-S(473) and FoxO1-S(256) phosphorylation. These results establish a novel link between Elovl5-mediated synthesis of 18:1,n-7 and GNG through the control of the mTORC2-Akt-FoxO1 pathway.

Honey bees allocate tasks along reproductive and non-reproductive lines: the queen mates and lays eggs, whereas the workers nurse the brood and forage for food. Among workers, tasks are distributed according to age: young workers nurse and old workers fly out and forage. This task distribution in the colony is further regulated by an increase in juvenile hormone III as workers age and by pheromones. One such compound is ethyl oleate (EO), a primer pheromone that delays the onset of foraging in young workers. EO is produced by foragers when they are exposed to ethanol (from fermented nectar) while gathering food. EO is perceived by younger bees via olfaction. We describe here the seasonal variation of EO production and the effects of Methoprene, a juvenile hormone analog. We found that honey bee workers biosynthesize more EO during the growing season than during the fall and winter months, reaching peak levels at late spring or summer. When caged workers were fed with syrup+d(6)-ethanol, labeled EO accumulated in the honey crop and large amounts exuded to the exoskeleton. Exuded levels were high for several hours after exposure to ethanol. Treatment with Methoprene increased the production of EO in worker bees, by speeding up its movement from biosynthetic sites to the exoskeleton, where EO evaporates. Crop fluid from bees collected monthly during the growing season showed a modest seasonal variation of in vitro EO biosynthetic activity that correlated with the dry and sunny periods during which bees could forage., (Copyright © 2012 Elsevier Ltd. All rights reserved.)

Honey bees undergo a physiological transition from nursing to foraging approximately 21 days after adult emergence. This transition is delayed by ethyl oleate (EO), a primer pheromone produced by foragers when exposed to ethanol from fermented nectar. We demonstrate here that two secreted α/β-hydrolases (BeeBase ID: GB11403 and GB13365) are responsible for the reversible esterification of ethanol with oleic acid, giving EO. Expression of hydrolase GB11403 was shown to be significantly up-regulated in foragers, relative to nurses. Tissue perfusion experiments with labeled substrates consistently localized the highest level of EO production in the head, whereas in situ imaging revealed expression of relevant EO biosynthetic genes and enzymatic activity along the esophagus, the site of ethanol exposure during nectar intake. Both α/β-hydrolases were expressed in Pichia pastoris, purified and were shown produce EO in vitro. Experiments with live bees fed ethanol demonstrated that EO formed in regurgitate accumulates in the honey crop and exudes to the exoskeleton, from where it exerts its primer effect on younger bees., (Copyright © 2012. Published by Elsevier Ltd.)

Objective: To investigate the effect of artermisinic acid on the secondary metabolites production of Panax quinquefolium crown galls., Methods: Artemisinic acid was added into the suspended cells of Panax quinquefolium crown galls and co-culture for two days. Products were isolated with chromatographic method., Results: Three hydroxyl octadecenoic acids [9,12,13-trihydroxy-10-octadecenoic acid (1), 11,12,13-trihydroxy-9-octadecenoic acid (2) and 11-hydroxy-12,13-epoxy-9-octadecenoic acid (3)] were isolated from crown galls of Panax quinquefolium., Conclusion: Artermisinic acid as one of the new type of phytohormones that might induce the production of 13-lipoxygenases in crown galls of Panax quinquefolium.

Lysine acetylation is a major post-translational modification of proteins and regulates many physiological processes such as metabolism, cell migration, aging, and inflammation. Proteomic studies have identified numerous lysine-acetylated proteins in human and mouse models (Kim, S. C., Sprung, R., Chen, Y., Xu, Y., Ball, H., Pei, J., Cheng, T., Kho, Y., Xiao, H., Xiao, L., Grishin, N. V., White, M., Yang, X. J., and Zhao, Y. (2006) Mol. Cell 23, 607-618). One family of proteins identified in this study was the murine glycine N-acyltransferase (GLYAT) enzymes, which are acetylated on lysine 19. Lysine 19 is a conserved residue in human glycine N-acyltransferase-like 2 (hGLYATL2) and in several other species, showing that this residue may be important for enzyme function. Mutation of lysine 19 in recombinant hGLYATL2 to glutamine (K19Q) and arginine (K19R) resulted in a 50-80% lower production of N-oleoyl glycine and N-arachidonoylglycine, indicating that lysine 19 is important for enzyme function. LC/MS/MS confirmed that Lys-19 is not acetylated in wild-type hGLYATL2, indicating that Lys-19 requires to be deacetylated for full activity. The hGLYATL2 enzyme conjugates medium- and long-chain saturated and unsaturated acyl-CoA esters to glycine, resulting in the production of N-oleoyl glycine and also N-arachidonoyl glycine. N-Oleoyl glycine and N-arachidonoyl glycine are structurally and functionally related to endocannabinoids and have been identified as signaling molecules that regulate functions like the perception of pain and body temperature and also have anti-inflammatory properties. In conclusion, acetylation of lysine(s) in hGLYATL2 regulates the enzyme activity, thus linking post-translational modification of proteins with the production of biological signaling molecules, the N-acyl glycines.

CD36 is a ubiquitous membrane glycoprotein that binds long-chain fatty acids. The presence of a functional CD36 is required for the induction of satiety by a lipid load and its role as a lipid receptor driving cellular signal has recently been demonstrated. Our project aimed to further explore the role of intestinal CD36 in the regulation of food intake. Duodenal infusions of vehicle or sulfo-N-succinimidyl-oleate (SSO) was performed prior to acute infusions of saline or Intralipid (IL) in mice. Infusion of minute quantities of IL induced a decrease in food intake (FI) compared to saline. Infusion of SSO had the same effect but no additive inhibitory effect was observed in presence of IL. No IL- or SSO-mediated satiety occurred in CD36-null mice. To determine whether the CD36-mediated hypophagic effect of lipids was maintained in animals fed a satietogen diet, mice were subjected to a High-Protein diet (HPD). Concomitantly with the satiety effect, a rise in intestinal CD36 gene expression was observed. No satiety effect occurred in CD36-null mice. HPD-fed WT mice showed a diminished FI compared to control mice, after saline duodenal infusion. But there was no further decrease after lipid infusion. The lipid-induced decrease in FI observed on control mice was accompanied by a rise in jejunal oleylethanolamide (OEA). Its level was higher in HPD-fed mice than in controls after saline infusion and was not changed by lipids. Overall, we demonstrate that lipid binding to intestinal CD36 is sufficient to produce a satiety effect. Moreover, it could participate in the satiety effect induced by HPD. Intestine can modulate FI by several mechanisms including an increase in OEA production and CD36 gene expression. Furthermore, intestine of mice adapted to HPD have a diminished capacity to modulate their food intake in response to dietary lipids.

Heterotrophic oleaginous microorganisms are capable of producing over 20% of their weight in single cell oils (SCOs) composed of triacylglycerols (TAGs). These TAGs contain fatty acids, such as palmitic, stearic and oleic acids, that are well-suited for biodiesel applications. Although some of these microbes are able to accumulate SCOs while growing on inexpensive agro-industrial biomass, the competition with plant oil resources means that a significant increase in productivity is desired. The present review aims to summarize recent details in lipid metabolism research and engineering (e.g. direct fatty acid ethyl ester production), as well as culture condition optimization and innovations, such as solid-state or semi-solid-state fermentation, that can all contribute to higher productivity and further advancement of the field., (Copyright © 2010 Elsevier Ltd. All rights reserved.)

In this study, the immobilized lipase was prepared by fabric membrane adsorption in fermentation broth. The lipase immobilization method in fermentation broth was optimized on broth activity units and pH adjustments. The viscose fermentation broth can be used with a certain percentage of dilution based on the original broth activity units. The fermentation broth can be processed directly without pH adjustment. In addition, the oleic acid ethyl ester production in solvent-free system catalyzed by the immobilized lipase was optimized. The molar ratio of ethanol to oil acid, the enzyme amount, the molecular amount, and the temperature were 1:1, 12% (w/w), 9% (w/w)(based the total amount of reaction mixture), and 30 °C, respectively. Finally, the optimal condition afforded at least 19 reuse numbers with esterification rate above 80% under stepwise addition of ethanol. Due to simple lipase immobilization preparation, acceptable esterification result during long-time batch reactions and lower cost; the whole process was suitable for industrial ethyl oleate production.

Apart from its role during labor and lactation, oxytocin is involved in several other functions. Interestingly, oxytocin- and oxytocin receptor-deficient mice develop late-onset obesity with normal food intake, suggesting that the hormone might exert a series of beneficial metabolic effects. This was recently confirmed by data showing that central oxytocin infusion causes weight loss in diet-induced obese mice. The aim of the present study was to unravel the mechanisms underlying such beneficial effects of oxytocin. Chronic central oxytocin infusion was carried out in high fat diet-induced obese rats. Its impact on body weight, lipid metabolism and insulin sensitivity was determined. We observed a dose-dependent decrease in body weight gain, increased adipose tissue lipolysis and fatty acid β-oxidation, as well as reduced glucose intolerance and insulin resistance. The additional observation that plasma oxytocin levels increased upon central infusion suggested that the hormone might affect adipose tissue metabolism by direct action. This was demonstrated using in vitro, ex vivo, as well as in vivo experiments. With regard to its mechanism of action in adipose tissue, oxytocin increased the expression of stearoyl-coenzyme A desaturase 1, as well as the tissue content of the phospholipid precursor, N-oleoyl-phosphatidylethanolamine, the biosynthetic precursor of the oleic acid-derived PPAR-alpha activator, oleoylethanolamide. Because PPAR-alpha regulates fatty acid β-oxidation, we hypothesized that this transcription factor might mediate the oxytocin effects. This was substantiated by the observation that, in contrast to its effects in wild-type mice, oxytocin infusion failed to induce weight loss and fat oxidation in PPAR-alpha-deficient animals. Altogether, these results suggest that oxytocin administration could represent a promising therapeutic approach for the treatment of human obesity and type 2 diabetes.

Background: The alteration of fatty acid profiles in soybean [Glycine max (L.) Merr.] to improve soybean oil quality is an important and evolving theme in soybean research to meet nutritional needs and industrial criteria in the modern market. Soybean oil with elevated oleic acid is desirable because this monounsaturated fatty acid improves the nutrition and oxidative stability of the oil. Commodity soybean oil typically contains 20% oleic acid and the target for high oleic acid soybean oil is approximately 80% of the oil; previous conventional plant breeding research to raise the oleic acid level to just 50-60% of the oil was hindered by the genetic complexity and environmental instability of the trait. The objective of this work was to create the high oleic acid trait in soybeans by identifying and combining mutations in two delta-twelve fatty acid desaturase genes, FAD2-1A and FAD2-1B., Results: Three polymorphisms found in the FAD2-1B alleles of two soybean lines resulted in missense mutations. For each of the two soybean lines, there was one unique amino acid change within a highly conserved region of the protein. The mutant FAD2-1B alleles were associated with an increase in oleic acid levels, although the FAD2-1B mutant alleles alone were not capable of producing a high oleic acid phenotype. When existing FAD2-1A mutations were combined with the novel mutant FAD2-1B alleles, a high oleic acid phenotype was recovered only for those lines which were homozygous for both of the mutant alleles., Conclusions: We were able to produce conventional soybean lines with 80% oleic acid in the oil in two different ways, each requiring the contribution of only two genes. The high oleic acid soybean germplasm developed contained a desirable fatty acid profile, and it was stable in two production environments. The presumed causative sequence polymorphisms in the FAD2-1B alleles were developed into highly efficient molecular markers for tracking the mutant alleles. The resources described here for the creation of high oleic acid soybeans provide a framework to efficiently develop soybean varieties to meet changing market demands.

Pheromones in social insects play a key role in the regulation of group homoeostasis. It is well-established that parasites can modify hormone signaling of their host, but less is known about the effect of parasites on pheromone signaling in insect societies. We, thus, tested in honey bees (Apis mellifera) the effect of the widespread parasite Nosema spp. on the production of ethyl oleate (EO), the only identified primer pheromone in honey bee workers. Since environmental stressors like pesticides also can weaken honey bees, we also analyzed the effect of imidacloprid, a neonicotinoid widely used in agriculture, on EO production. We show that, contrary to imidacloprid, Nosema spp. significantly altered EO production. In addition, the level of Nosema infection was correlated positively with the level of EO production. Since EO is involved in the regulation of division of labor among workers, our result suggests that the changes in EO signaling induced by parasitism have the potential to disturb the colony homoeostasis.

There is increasing evidence that the metabolic state of the mother during pregnancy affects long-term glucose and lipid metabolism of the offspring. The liver X receptors (LXR)α and -β are key regulators of cholesterol, fatty acid, and glucose metabolism. LXRs are activated by oxysterols and expressed in fetal mouse liver from day 10 of gestation onward. In the present study, we aimed to elucidate whether in utero pharmacological activation of LXR would influence fetal fatty acid and glucose metabolism and whether this would affect lipid homeostasis at adult age. Exposure of pregnant mice to the synthetic LXR agonist T0901317 increased hepatic mRNA expression levels of Lxr target genes and hepatic and plasma triglyceride levels in fetuses and dams. T0901317 treatment increased absolute de novo synthesis and chain elongation of hepatic oleic acid in dams and fetuses. T0901317 exposure in utero influenced lipid metabolism in adulthood in a sex-specific manner; hepatic triglyceride content was increased (+45%) in male offspring and decreased in female offspring (-42%) when they were fed a regular chow diet compared with untreated sex controls. Plasma and hepatic lipid contents and hepatic gene expression patterns in adult male or female mice fed a high-fat diet were not affected by T0901317 pretreatment. We conclude that LXR treatment of pregnant mice induces immediate effects on lipid metabolism in dams and fetuses. Despite the profound changes during fetal life, long-term effects appeared to be rather mild and sex selective without modulating the lipid response to a high-fat diet.

Oleamide (cis-9-octadecenamide) is the prototype long chain primary fatty acid amide lipid messenger. The natural occurrence of oleamide was first reported in human serum in 1989. Subsequently oleamide was shown to accumulate in the cerebrospinal fluid of sleep-deprived cats and to induce sleep when administered to experimental animals. Accordingly, oleamide first became known for its potential role in the mechanisms that mediate the drive to sleep. Oleamide also has profound effects on thermoregulation and acts as an analgesic in several models of experimental pain. Although these important pharmacologic effects are well establish, the biochemical mechanism for the synthesis of oleamide has not yet been defined. This chapter reviews the biosynthetic pathways that have been proposed and highlights two mechanisms which are most supported by experimental evidence: the generation of oleamide from oleoylglycine by the neuropeptide processing enzyme, peptidylglycine alpha-amidating monooxygenase (PAM), and alternatively, the direct amidation of oleic acid via oleoyl coenzyme A by cytochrome c using ammonia as the nitrogen source. The latter mechanism is discussed in the context of apoptosis where oleamide may play a role in regulating gap junction communication. Lastly, several considerations and caveats pertinent to the future study oleamide biosynthesis are discussed.

This paper reports a study of the enzymatic esterification of oleic acid and ethanol. The reaction was catalyzed by lipases produced by solid-state fermentation with Rhizopus sp. Olive oil and perlite were used as an inducer and inert support, respectively. Synthesis of ethyl oleate was carried out in a 10-mL batch reactor with magnetic stirring. The effects of substrate ratios, biocatalyst concentration, and temperature on the reaction rate and conversion efficiency were evaluated. The highest reaction rate (1.64 mmol/L min) was reached with an oleic acid/ethanol mol ratio of 1:5 (oleic acid 50 mM:ethanol 250 mM) and 1 g of biocatalyst. Conversions approaching 100% were obtained after 60 min of reaction at 45 degrees C with n-hexane as a solvent. The initial reaction rate increased proportionally with respect to biocatalyst concentration, which suggests that the reaction rate was not controlled by mass transfer. The biocatalyst retained more than 80% of its catalytic activity after 7 months of storage at 4 degrees C. The results demonstrate that the biocatalyst produced by Rhizopus sp. in solid-state fermentation can be successfully used for ethyl oleate synthesis over short reaction periods under conditions when ethanol is in excess.

The identification of two biologically active fatty acid amides, N-arachidonoylethanolamine (anandamide) and oleamide, has generated a great deal of excitement and stimulated considerable research. However, anandamide and oleamide are merely the best-known and best-understood members of a much larger family of biologically occurring fatty acid amides. In this review, we will outline which fatty acid amides have been isolated from mammalian sources, detail what is known about how these molecules are made and degraded in vivo, and highlight their potential for the development of novel therapeutics.

Pharmacological administration of the natural lipid amide, oleoylethanolamide (OEA), inhibits food intake in free-feeding rodents by prolonging latency to feed and postmeal interval. This anorexic effect is mediated by activation of type-alpha peroxisome proliferator-activated receptors (PPAR-alpha). Food intake stimulates mucosal cells in duodenum and jejunum to generate OEA, suggesting that this lipid-derived messenger may act as a local satiety hormone. As a test of this hypothesis, here, we examined whether targeted enhancement of OEA production in the small intestine affects feeding behavior in rats. We constructed an adenoviral vector (Ad-NPLD) that directs overexpression of the enzyme N-acylphosphatidylethanolamine (NAPE)-phospholipase D (PLD), which catalyzes the hydrolysis of NAPE to generate OEA. Intraduodenal injection of the Ad-NPLD vector resulted in a time-dependent increase in NAPE-PLD expression and OEA production, which was restricted to the proximal small intestine. No such effect was observed after administration of a control adenoviral vector. Enhanced OEA production in Ad-NPLD-injected animals was temporally associated with increased expression of two PPAR-alpha target genes (PPAR-alpha and CD36) and with decreased food intake. The hypophagic phenotype of Ad-NPLD-injected rats was attributable to increase feeding latency and postmeal interval, rather than decreased meal size. The results suggest that localized changes in OEA production in the small intestine, such as those produced by food intake, are sufficient to induce in rats a state of across-meal satiety similar to that elicited by systemic administration of exogenous OEA.