Odd-numbered very-long-chain fatty acids from the microbial, animal and plant kingdoms

Spatially resolved lipidomics shows conditional transfer of lipids produced by Bacteroides thetaiotaomicron into the mouse gut

The extent to which bacterial lipids produced by the gut microbiota penetrate host tissues is unclear. Here, we combined mass spectrometry approaches to identify lipids produced by the human gut symbiont Bacteroides thetaiotaomicron (B. theta) and spatially track these bacterial lipids in the mouse colon. We characterize 130 B. theta lipids by liquid chromatography-tandem mass spectrometry (LC-MS/MS), using wild-type and mutant B. theta strains to confidently identify lipid structures and their interconnected pathways in vitro. Of these, 103 B. theta lipids can be detected and spatially mapped in a single MALDI mass spectrometry imaging run. We map unlabeled bacterial lipids across colon sections of germ-free and specific-pathogen-free (SPF) mice and mice mono-colonized with wild-type or sphingolipid-deficient (BTMUT) B. theta. We observe co-localization of bacterially derived phosphatidic acid with host tissues in BTMUT mice, consistent with lipid penetration into host tissues. These results indicate limited and selective transfer of bacterial lipids to the host.

Daphnane diterpenoid orthoesters with an odd-numbered aliphatic side chain from Daphne pedunculata

Daphnane diterpenoids were recognized for their extensive range of potent biological activities. In the present study, phytochemical investigation including LC-MS/MS analysis resulted in the identification of five daphnane diterpenoid orthoesters (1-5). Among the five daphnane diterpenoids, two previously unreported compounds, daphnepedunins I and J (2 and 4) were isolated from Daphne pedunculata. The structure of new compounds was elucidated with extensive physicochemical and spectroscopic analyses. Their structure was characterized by the presence of an unusual odd-numbered aliphatic chain connected to an orthoester. The isolated compounds were evaluated for their anti-HIV activity against HIV-1 infection of MT4 cells, and the results indicated that compound 1 showed the most potent anti-HIV activity with an IC50 value of 0.82 nM.

Changes in fecal lipidome after treatment with ivacaftor without changes in microbiome or bile acids

BACKGROUND

Alterations in gastrointestinal health are prominent manifestations of cystic fibrosis (CF) and can independently impact pulmonary function. Ivacaftor has been associated with robust improvements in pulmonary function and weight gain, but less is known about the impact of ivacaftor on the fecal microbiome, lipidome, and bile acids.

METHODS

Stool samples from 18 patients with CF and gating mutations (ages 6-61 years, 13 pancreatic insufficient) were analyzed for fecal microbiome and lipidome composition as well as bile acid concentrations at baseline and after 3 months of treatment with ivacaftor. Microbiome composition was also assessed in a healthy reference cohort.

RESULTS

Alpha and beta diversity of the microbiome were different between CF and reference cohort at baseline, but no treatment effect was seen in the CF cohort between baseline and 3 months. Seven lipids increased with treatment. No differences were seen in bile acid concentrations after treatment in CF. At baseline, 403 lipids and unconjugated bile acids were different between pancreatic insufficient (PI-CF) and sufficient (PS-CF) groups and 107 lipids were different between PI-CF and PS-CF after 3 months of treatment.

CONCLUSIONS

The composition and diversity of the fecal microbiome were different in CF as compared to a healthy reference, and did not change after 3 months of ivacaftor. We detected modest differences in the fecal lipidome with treatment. Differences in lipid and bile acid profiles between PS-CF and PI-CF were attenuated after 3 months of treatment.

Fatty acid analysis in serum of patients with elevated lipoprotein(a) and cardiovascular disease undergoing lipoprotein apheresis

BACKGROUND

Lipoprotein apheresis (LA) is an extracorporeal treatment that transiently reduces lipoprotein (a) [Lp(a)] by 60% and leads to an 80-92% reduction in major adverse cardiovascular events. LA has a significant impact on lipid profile in serum of patients with atherosclerotic cardiovascular disease.

OBJECTIVE

To investigate the effects of LA on the composition of serum fatty acids (FAs), focusing on those which could have an impact on cardiovascular disease (CVD).

METHODS

This is a prospective study in the First Department of Cardiology of the Medical University of Gdansk, Poland. Serum samples were collected from 28 patients before LA, just after the procedure, and 7 days after LA. Additionally, in a smaller group of patients, the samples were collected after a second tour of LA (2 weeks later), as well as after 1 year from the first procedure. The serum FA profile was analyzed using gas chromatography-mass spectrometry.

RESULTS

After the LA procedure, a substantial change in serum FA composition along with low-density lipoprotein cholesterol (LDL-C) and Lp(a) decrease were observed 7 days after procedure, but these parameters returned to the values similar to those before procedure after 14 days. Very long-chain FAs (VLCFAs) and very long-chain monounsaturated FAs (VLC-MUFAs) were eluted at 57% and remained low even 7 days after LA (p=0.027 and p < 0.001, respectively). We also observed an increase in the percentage of total branched-chain FAs (BCFAs) (p=0.004) and anteiso BCFAs (p=0.012) after LA. After 1 year of regular LA, a substantial decrease in serum VLC-MUFAs and n3 polyunsaturated LA (PUFAs) were noted.

CONCLUSIONS

Decreased VLCFAs and VLC-MUFAs involved in CVD development remained low even 7 days after LA. An acute increase in the levels of anti-inflammatory BCFAs was observed. In turn long-term regular administration of LA substantially decreased VLC-MUFA and n3 PUFA.

Explorative characterization and taxonomy-aligned comparison of alterations in lipids and other biomolecules in Antarctic bacteria grown at different temperatures

Temperature significantly impacts bacterial physiology, metabolism and cell chemistry. In this study, we analysed lipids and the total cellular biochemical profile of 74 fast-growing Antarctic bacteria grown at different temperatures. Fatty acid diversity and temperature-induced alterations aligned with bacterial classification-Gram-groups, phylum, genus and species. Total lipid content, varied from 4% to 19% of cell dry weight, was genus- and species-specific. Most bacteria increased lipid content at lower temperatures. The effect of temperature on the profile was complex and more species-specific, while some common for all bacteria responses were recorded. Gram-negative bacteria adjusted unsaturation and acyl chain length. Gram-positive bacteria adjusted methyl branching (anteiso-/iso-), chain length and unsaturation. Fourier transform infrared spectroscopy analysis revealed Gram-, genus- and species-specific changes in the total cellular biochemical profile triggered by temperature fluctuations. The most significant temperature-related alterations detected on all taxonomy levels were recorded for mixed region 1500-900 cm-1 , specifically the band at 1083 cm-1 related to phosphodiester groups mainly from phospholipids (for Gram-negative bacteria) and teichoic/lipoteichoic acids (for Gram-positive bacteria). Some changes in protein region were detected for a few genera, while the lipid region remained relatively stable despite the temperature fluctuations.

Effect of Primary Versus Revisional One Anastomosis Gastric Bypass (OAGB) on Fatty Acid Profile

INTRODUCTION

One anastomosis gastric bypass (OAGB) is one option of a revisional procedure for failed sleeve gastrectomy. Moreover, it can be used as a primary bariatric procedure, and is an effective surgery resulting in significant weight loss and the resolution or improvement of obesity-associated medical problems, accompanied by low perioperative complications. However, as with any therapy, OAGB has its limitations, including micronutrient deficiency or malnutrition. In our study, we compared the fatty acid (FA) profile in serum of patients after both primary OAGB (pOAGB) and revisional OAGB (rOAGB) to identify potential postsurgical FA alterations.

METHODS

This is a retrospective study on patients with obesity who underwent OAGB procedures (pOAGB n=68; rOAGB n=17), conducted from 2016 to 2018. In blood, we analyzed a series of biochemical parameters, and in the serum, the FA profile was determined using gas chromatography-mass spectrometry.

RESULTS

The percentage of excess BMI loss (% EBMIL) after pOAGB was 73.5 ± 2.47% in comparison to 45.9 ± 4.15% in the rOAGB group (p<0.001). In contrast to the lack of effect of rOAGB on most polyunsaturated FAs, in the pOAGB group, there was a decrease in eicosapentaenoic acid, and eicosatetraenoic and docosahexaenoic acid levels (p<0.001). We also found a decrease in very long-chain FAs (VLCFAs) and an increase in branched-chain FAs (BCFAs) after both types of OAGB procedure.

CONCLUSIONS

Both OAGB procedures improved the profile of most FAs, leading to a decrease in VLCFAs, which are considered harmful, and an improvement in BCFAs, which are considered to be beneficial. There is a need to further investigate the possibility of n-3 polyunsaturated FA supplementation after pOAGB, due to the large decrease in these FAs after pOAGB.

A marine-derived fatty acid targets the cell membrane of Gram-positive bacteria

IMPORTANCE

With the lack of new antibiotics in the drug discovery pipeline, coupled with accelerated evolution of antibiotic resistance, new sources of antibiotics that target pathogens of clinical importance are paramount. Here, we use bacterial cytological profiling to identify the mechanism of action of the monounsaturated fatty acid (Z)-13-methyltetra-4-decenoic acid isolated from the marine bacterium Olleya marilimosa with antibacterial effects against Gram-positive bacteria. The fatty acid antibiotic was found to rapidly destabilize the cell membrane by pore formation and membrane aggregation in Bacillus subtilis, suggesting that this fatty acid may be a promising adjuvant used in combination to enhance antibiotic sensitivity.

The lipidomic correlates of epigenetic aging across the adult lifespan: A population-based study

Lipid signaling is involved in longevity regulation, but which specific lipid molecular species affect human biological aging remains largely unknown. We investigated the relation between complex lipids and DNA methylation-based metrics of biological aging among 4181 participants (mean age 55.1 years (range 30.0-95.0)) from the Rhineland Study, an ongoing population-based cohort study in Bonn, Germany. The absolute concentration of 14 lipid classes, covering 964 molecular species and 267 fatty acid composites, was measured by Metabolon Complex Lipid Panel. DNA methylation-based metrics of biological aging (AgeAccelPheno and AgeAccelGrim) were calculated based on published algorithms. Epigenome-wide association analyses (EWAS) of biological aging-associated lipids and pathway analysis were performed to gain biological insights into the mechanisms underlying the effects of lipidomics on biological aging. We found that higher levels of molecular species belonging to neutral lipids, phosphatidylethanolamines, phosphatidylinositols, and dihydroceramides were associated with faster biological aging, whereas higher levels of lysophosphatidylcholine, hexosylceramide, and lactosylceramide species were associated with slower biological aging. Ceramide, phosphatidylcholine, and lysophosphatidylethanolamine species with odd-numbered fatty acid tail lengths were associated with slower biological aging, whereas those with even-numbered chain lengths were associated with faster biological aging. EWAS combined with functional pathway analysis revealed several complex lipids associated with biological aging as important regulators of known longevity and aging-related pathways.

Comprehensive Characterization of Oils and Fats of Six Species from the Colombian Amazon Region with Industrial Potential

The Colombian Amazon is a megadiverse region with high potential for commercial use in the pharmaceutical, food, and cosmetic industries, constantly expanding and looking for new alternatives from natural resources; unfortunately, few characterization reports of its profitable non-timber species in Colombia have been conducted. This work aimed to perform a comprehensive analysis of traditionally used species: Carapa guianensis (Andiroba), Euterpe precatoria (Asai), Mauritia flexuosa (Miriti), Astrocaryum murumuru (Murumuru), Plukenetia volubilis (Sacha Inchi), and Caryodendron orinocense H.Karst (Cacay). For this purpose, oil and fat quality indices, phytosterol, carotenoid, tocopherol, and tocotrienol content, as well as density and refractive index, were measured to establish their quality level. Multivariate analysis showed four groups of samples; such differences were mainly due to the composition rather than quality indices and physical properties, especially the content of saturated and unsaturated fatty acids. All species reported a precise composition, which makes them noninterchangeable, and Miriti oil arose as the most versatile ingredient for the industry. The Colombian Amazon region is a promising source of quality raw material, especially for oils/fats and unsaturated fatty acids; this resulted in the most interest for pharmaceutical, food, and cosmetic purposes.

Molecular probing of dissolved organic matter and its transformation in a woolen textile wastewater treatment station

Woolen textile industry produces enormous wastewater (WTIW) with high pollution loads, and needs to be treated by wastewater treatment stations (WWTS) before centralized treatment. However, WTIW effluent still contains many biorefractory and toxic substances; thus, comprehensive understandings of dissolved organic matter (DOM) of WTIW and its transformation are essential. In this study, total quantity indices, size exclusion chromatography, spectral methods, and Fourier transform ion cyclotron resonance mass spectrometry (FTICR MS) were used for comprehensively characterizing DOM and its transformation during full-scale treatments, including influent, regulation pool (RP), flotation pool (FP), up-flow anaerobic sludge bed (UA), anaerobic/oxic (AO) and effluent. DOM in influent featured a large molecular weight (5-17 kDa), toxicity (0.201 HgCl₂ mg/L), and a protein content of 338 mg C/L. FP largely removed 5-17 kDa DOM with the formation of 0.45-5 kDa DOM. UA and AO removed 698 and 2042 chemicals, respectively, which were primarily saturated components (H/C > 1.5); however, both UA and AO contributed to the formation of 741 and 1378 stable chemicals, respectively. Good correlations were found among water quality indices and spectral/molecular indices. Our study reveals the molecular composition and transformation of WTIW DOM during treatments and encourages the optimization of the employed processes in WWTS.

Untargeted lipidomic profiling of grapes highlights the importance of modified lipid species beyond the traditional compound classes

The aim of this paper is to provide a detailed characterisation of grape lipidome. To achieve this objective, it starts by describing a pipeline implemented in R software to allow the semi-automatic annotation of the detected lipid species. It also provides an extensive description of the different properties of each molecule (such as retention time dependencies, mass accuracy, adduct formation and fragmentation patterns), which allowed the annotations to be made more accurately. Most annotated lipids in the grape samples were (lyso)glycerophospholipids and glycerolipids, although a few free fatty acids, hydroxyceramides and sitosterol esters were also observed. The proposed pipeline also allowed the identification of a series of methylated glycerophosphates never previously observed in grapes. The current results highlight the importance of expanding chemical analyses beyond the classical lipid categories.

Coral Lipidome: Molecular Species of Phospholipids, Glycolipids, Betaine Lipids, and Sphingophosphonolipids

Coral reefs are the most biodiversity-rich ecosystems in the world's oceans. Coral establishes complex interactions with various microorganisms that constitute an important part of the coral holobiont. The best-known coral endosymbionts are Symbiodiniaceae dinoflagellates. Each member of the coral microbiome contributes to its total lipidome, which integrates many molecular species. The present study summarizes available information on the molecular species of the plasma membrane lipids of the coral host and its dinoflagellates (phosphatidylcholine (PC), phosphatidylethanolamine (PE), phosphatidylserine (PS), phosphatidylinositol (PI), ceramideaminoethylphosphonate, and diacylglyceryl-3-O-carboxyhydroxymethylcholine), and the thylakoid membrane lipids of dinoflagellates (phosphatidylglycerol (PG) and glycolipids). Alkyl chains of PC and PE molecular species differ between tropical and cold-water coral species, and features of their acyl chains depend on the coral's taxonomic position. PS and PI structural features are associated with the presence of an exoskeleton in the corals. The dinoflagellate thermosensitivity affects the profiles of PG and glycolipid molecular species, which can be modified by the coral host. Coral microbiome members, such as bacteria and fungi, can also be the source of the alkyl and acyl chains of coral membrane lipids. The lipidomics approach, providing broader and more detailed information about coral lipid composition, opens up new opportunities in the study of biochemistry and ecology of corals.

Microbial production of odd-chain fatty acids

Odd-chain fatty acids (OcFAs) and their derivatives have attracted much attention due to their beneficial physiological effects and their potential to be alternatives to advanced fuels. However, cells naturally produce even-chain fatty acids (EcFAs) with negligible OcFAs. In the process of biosynthesis of fatty acids (FAs), the acetyl-CoA serves as the starter unit for EcFAs, and propionyl-CoA works as the starter unit for OcFAs. The lack of sufficient propionyl-CoA, the precursor, is usually regarded as the main restriction for large-scale bioproduction of OcFAs. In recent years, synthetic biology strategies have been used to modify several microorganisms to produce more propionyl-CoA that would enable an efficient biosynthesis of OcFAs. This review discusses several reported and potential metabolic pathways for propionyl-CoA biosynthesis, followed by advances in engineering several cell factories for OcFAs production. Finally, trends and challenges of synthetic biology driven OcFAs production are discussed.

Gut microbiome lipid metabolism and its impact on host physiology

Metabolites produced by commensal gut microbes impact host health through their recognition by the immune system and their influence on numerous metabolic pathways. Notably, the gut microbiota can both transform and synthesize lipids as well as break down dietary lipids to generate secondary metabolites with host modulatory properties. Although lipids have largely been consigned to structural roles, particularly in cell membranes, recent research has led to an increased appreciation of their signaling activities, with potential impacts on host health and physiology. This review focuses on studies that highlight the functions of bioactive lipids in mammalian physiology, with a special emphasis on immunity and metabolism.

Synthesis and Comprehensive in Vivo Activity Profiling of Olean-12-en-28-ol, 3β-Pentacosanoate in Experimental Autoimmune Encephalomyelitis: A Natural Remyelinating and Anti-Inflammatory Agent

Multiple sclerosis (MS) treatment has received much attention, yet there is still no certain cure. We herein investigate the therapeutic effect of olean-12-en-28-ol, 3β-pentacosanoate (OPCA) on a preclinical model of MS. First, OPCA was synthesized semisynthetically and characterized. Then, the mice with MOG_35-55-induced experimental autoimmune/allergic encephalomyelitis (EAE) were given OPCA along with a reference drug (FTY720). Biochemical, cellular, and molecular analyses were performed in serum and brain tissues to measure anti-inflammatory and neuroprotective responses. OPCA treatment protected EAE-induced changes in mouse brains maintaining blood-brain barrier integrity and preventing inflammation. Moreover, the protein and mRNA levels of MS-related genes such as HLD-DR1, CCL5, TNF-α, IL6, and TGFB1 were significantly reduced in OPCA-treated mouse brains. Notably, the expression of genes, including PLP, MBP, and MAG, involved in the development and structure of myelin was significantly elevated in OPCA-treated EAE. Furthermore, therapeutic OPCA effects included a substantial reduction in pro-inflammatory cytokines in the serum of treated EAE animals. Lastly, following OPCA treatment, the promoter regions for most inflammatory regulators were hypermethylated. These data support that OPCA is a valuable and appealing candidate for human MS treatment since OPCA not only normalizes the pro- and anti-inflammatory immunological bias but also stimulates remyelination in EAE.

Mutualistic microbial community of Bacillus amyloliquefaciens and recombinant Yarrowia lipolytica co-produced lipopeptides and fatty acids from food waste

Bioconversion is an important method for transforming food waste (FW) into high value-added products, rendering it harmless, and recycling resources. An artificial microbial consortium (AMC) was constructed to produce FW-based lipopeptides in order to investigate the strategy of FW bioconversion into value-added products. Exogenous fatty acids as a precursor significantly improved the lipopeptide production of Bacillus amyloliquefaciens HM618. To enhance fatty acid synthesis and efflux in AMC, the recombinant Yarrowia lipolytica YL21 (strain YL21) was constructed by screening 12 target genes related to fatty acids to replace exogenous fatty acids in order to improve lipopeptide production. The levels of fengycin, surfactin, and iturin A in the AMC of strains HM618 and YL21 reached 76.19, 192.80, and 31.32 mg L^-1, increasing 7.24-, 12.13-, and 3.23-fold compared to the results from the pure culture of strain HM618 in flask with Landy medium, respectively. Furthermore, free fatty acids were almost undetectable in the co-culture of strains HM618 and YL21, although its level was around 1.25 g L^-1 in the pure culture of strain YL21 with Landy medium. Interestingly, 470.24 mg L^-1 of lipopeptides and 18.11 g L^-1 of fatty acids were co-produced in this AMC in a bioreactor with FW medium. To our knowledge, it is the first report of FW biotransformation into co-produce of lipopeptides and fatty acids in the AMC of B. amyloliquefaciens and Y. lipolytica. These results provide new insights into the biotransformation potential of FW for value-added co-products by AMC.

Major dietary lipids in nutrition and health

In this chapter, an overview of the major lipids in the diet with emphasis in nutritional aspects is provided. Triacylglycerols, i.e., glycerol esterified with three fatty acids, are the predominant constituents in dietary lipids. Therefore, this chapter focuses on the nature and nutritional significance of the main fatty acids in the diet and their possible modifications during food processing and commercialization. The main fatty acids in dietary lipids are grouped into saturated, monounsaturated and polyunsaturated fatty acids. Nutritional implications, the latest intervention trials and health recommendations will be discussed. A brief description of the major sources of lipids in the diet is included, oils and fats standing out. Other food sources shortly commented are milk and dairy products, meat, poultry and eggs, fish, and structured lipids designed to improve functional and nutritional properties. Modifications of fatty acids as a result of processing and commercialization are discussed because of their great relevance for their health implications, especially oxidation compounds and trans fatty acids.

Associations of Region and Lactation Stage with Odd-Chain Fatty Acid Profile in Triglycerides of Breast Milk in China

Odd-chain fatty acids (OCFAs), with potential value for growing infants, have been reported in breast milk. The association of location and lactation stage with the profile and content of OCFAs in breast milk was studied. We analyzed 1487 breast milk samples collected from 12 areas in China, and 102 infant formulas from different brands were purchased from the local supermarket. The content of sn-2 C15:0 significantly decreased from the colostrum to the mature stage, while that of C17:0 was not significantly increased by the lactation stage (p > 0.05). The content of C15:0 and C17:0 significantly decreased dramatically after the colostrum period, while the content of C13:0 was highest in the mature stage. The level of C15:0 and C17:0 in human milk from Gansu and Xinjiang was significantly higher than that from other areas. Similar trends were observed on the level of sn-2 C15:0 and C17:0, whereas the content of sn-2 C11:0 and C13:0 was significantly higher in breast milk from Shandong. Based on the PDS-LA analysis, the difference among infant formulas, each stage of human milk and human milk from different locations were different. Research is needed to determine if there are health benefits associated with OCFAs.

Lipid Readjustment in Yarrowia lipolytica Odd-Chain Fatty Acids Producing Strains

Yarrowia lipolytica is a promising oleaginous yeast for producing unusual lipids, such as odd-chain fatty acids (OCFA). Their diverse applications and low natural production make OCFA particularly interesting. In recent studies, inhibiting the catabolic pathway of precursor, boosting precursor pools, and optimizing substrate combination greatly improved the production of OCFA in Y. lipolytica. We explored the lipid readjustment of OCFA in engineered Y. lipolytica strains. NPLC-Corona-CAD^® evidenced a time-dependent overproduction of free fatty acids, diglycerides, and phosphatidylcholine (PC) in obese LP compared to obese L. Phosphatidylethanolamine (PE) and phosphatidylinositol, largely overproduced in obese LP at 72 h compared to obese L, vanished at 216 h. The fatty acyls (FAs) composition of glycero- and glycerophospholipids was determined by NPLC-APPI⁺-HRMS from in-source generated monoacylglycerol-like fragment ions. C18:1 and C17:1 were predominant acylglycerols in obese L and obese LP, respectively. Phosphatidic acid, PE, and PC exhibited similar FAs composition but differed in their molecular species distributions. Cardiolipin (CL) is known to contain mostly C18:2 FAs corresponding to the composition in obese L, 50% of C18:2, and 35% of C18:1. In obese LP, both FAs dropped to drop to 20%, and C17:1 were predominant, reaching 55%. We hypothesize that CL-modified composition in obese LPs may alter mitochondrial function and limit lipid production.

Very long chain fatty acids

Very long chain fatty acids (VLCFAs) are important components of various lipid classes in most organisms, from bacteria to higher plants and mammals, including humans. VLCFAs, or very long chain polyunsaturated fatty acids (VLCPUFAs), can be defined as fatty acids with 23 or more carbon atoms in the molecule. The main emphasis in this review is on the analysis of these acids, including obtaining standards from natural sources or their synthesis. Furthermore, the occurrence and analysis of these compounds in both lower (bacteria, invertebrates) and higher organisms (flowering plants or mammals) are discussed in detail. Attention is paid to their biosynthesis, especially the elongation of very long chain fatty acids protein (ELOVL4). This review deals with papers describing these very interesting compounds, whose chemical, biochemical and biological properties have not been fully explored.

Plasmalogens and Photooxidative Stress Signaling in Myxobacteria, and How it Unmasked CarF/TMEM189 as the Δ1'-Desaturase PEDS1 for Human Plasmalogen Biosynthesis

Plasmalogens are glycerophospholipids with a hallmark sn-1 vinyl ether bond that endows them with unique physical-chemical properties. They have proposed biological roles in membrane organization, fluidity, signaling, and antioxidative functions, and abnormal plasmalogen levels correlate with various human pathologies, including cancer and Alzheimer’s disease. The presence of plasmalogens in animals and in anaerobic bacteria, but not in plants and fungi, is well-documented. However, their occurrence in the obligately aerobic myxobacteria, exceptional among aerobic bacteria, is often overlooked. Tellingly, discovery of the key desaturase indispensable for vinyl ether bond formation, and therefore fundamental in plasmalogen biogenesis, emerged from delving into how the soil myxobacterium Myxococcus xanthus responds to light. A recent pioneering study unmasked myxobacterial CarF and its human ortholog TMEM189 as the long-sought plasmanylethanolamine desaturase (PEDS1), thus opening a crucial door to study plasmalogen biogenesis, functions, and roles in disease. The findings demonstrated the broad evolutionary sweep of the enzyme and also firmly established a specific signaling role for plasmalogens in a photooxidative stress response. Here, we will recount our take on this fascinating story and its implications, and review the current state of knowledge on plasmalogens, their biosynthesis and functions in the aerobic myxobacteria.

Referenced Kendrick Mass Defect Annotation and Class-Based Filtering of Imaging MS Lipidomics Experiments

Because of their diverse functionalities in cells, lipids are of primary importance when characterizing molecular profiles of physiological and disease states. Imaging mass spectrometry (IMS) provides the spatial distributions of lipid populations in tissues. Referenced Kendrick mass defect (RKMD) analysis is an effective mass spectrometry (MS) data analysis tool for classification and annotation of lipids. Herein, we extend the capabilities of RKMD analysis and demonstrate an integrated method for lipid annotation and chemical structure-based filtering for IMS datasets. Annotation of lipid features with lipid molecular class, radyl carbon chain length, and degree of unsaturation allows image reconstruction and visualization based on each structural characteristic. We show a proof-of-concept application of the method to a computationally generated IMS dataset and validate that the RKMD method is highly specific for lipid components in the presence of confounding background ions. Moreover, we demonstrate an application of the RKMD-based annotation and filtering to matrix-assisted laser desorption/ionization (MALDI) IMS lipidomic data from human kidney tissue analysis.

The influence of different carbon sources on growth and single cell oil production in oleaginous yeasts Apiotrichum brassicae and Pichia kudriavzevii

Oleaginous yeasts offer an interesting possibility for renewable lipid production, since the single cell oil accumulated can be based on a wide range of cheap, waste-derived carbon sources. Here, several short chain carboxylic acids and sugars commonly found in these substrates were assessed as carbon sources for Apiotrichum brassicae and Pichia kudriavzevii. While both strains were able to utilize all carbon sources employed, high volumetric lipid productivities (0.4g/Lh) and lipid contents (68%) could be reached particularly with acetic acid as carbon source. Odd-numbered volatile fatty acids led to lower productivities and lipid contents, but the lipids contained unusually high proportions of odd-numbered fatty acids (up to 80% of total fatty acids). These fatty acids are rather uncommon in nature and might offer the possibility for various high value applications. In conclusion both strains are able to utilize a wide range of substrates potentially present in waste-derived substrates. Lipid content and volumetric lipid productivity strongly depend on the carbon source, with even-numbered volatile fatty acids resulting in the highest values. For volatile fatty acids in particular, the carbon source also strongly influences the composition of the lipids produced by the yeast strains.

The Biosynthesis and Metabolism of the N-Acylated Aromatic Amino Acids: N-Acylphenylalanine, N-Acyltyrosine, N-Acyltryptophan, and N-Acylhistidine

The fatty acid amides are a family of lipids composed of two chemical moieties, a fatty acid and a biogenic amine linked together in an amide bond. This lipid family is structurally related to the endocannabinoid anandamide (N-arachidonoylethanolamine) and, thus, is frequently referred to as a family of endocannabinoid-related lipids. The fatty acid amide family is divided into different classes based on the conjugate amine; anandamide being a member of the N-acylethanolamine class (NAE). Another class within the fatty acid amide family is the N-acyl amino acids (NA-AAs). The focus of this review is a sub-class of the NA-AAs, the N-acyl aromatic amino acids (NA-ArAAs). The NA-ArAAs are not broadly recognized, even by those interested in the endocannabinoids and endocannabinoid-related lipids. Herein, the NA-ArAAs that have been identified from a biological source will be highlighted and pathways for their biosynthesis, degradation, enzymatic modification, and transport will be presented. Also, information about the cellular functions of the NA-ArAAs will be placed in context with the data regarding the identification and metabolism of these N-acylated amino acids. A review of the current state-of-knowledge about the NA-ArAAs is to stimulate future research about this underappreciated sub-class of the fatty acid amide family.

Lipids and Trehalose Actively Cooperate in Heat Stress Management of Schizosaccharomyces pombe

Homeostatic maintenance of the physicochemical properties of cellular membranes is essential for life. In yeast, trehalose accumulation and lipid remodeling enable rapid adaptation to perturbations, but their crosstalk was not investigated. Here we report about the first in-depth, mass spectrometry-based lipidomic analysis on heat-stressed Schizosaccharomyces pombe mutants which are unable to synthesize (tps1Δ) or degrade (ntp1Δ) trehalose. Our experiments provide data about the role of trehalose as a membrane protectant in heat stress. We show that under conditions of trehalose deficiency, heat stress induced a comprehensive, distinctively high-degree lipidome reshaping in which structural, signaling and storage lipids acted in concert. In the absence of trehalose, membrane lipid remodeling was more pronounced and increased with increasing stress dose. It could be characterized by decreasing unsaturation and increasing acyl chain length, and required de novo synthesis of stearic acid (18:0) and very long-chain fatty acids to serve membrane rigidification. In addition, we detected enhanced and sustained signaling lipid generation to ensure transient cell cycle arrest as well as more intense triglyceride synthesis to accommodate membrane lipid-derived oleic acid (18:1) and newly synthesized but unused fatty acids. We also demonstrate that these changes were able to partially substitute for the missing role of trehalose and conferred measurable stress tolerance to fission yeast cells.

Searching for biomarkers in schizophrenia and psychosis: Case-control study using capillary electrophoresis and liquid chromatography time-of-flight mass spectrometry and systematic review for biofluid metabolites

Metabolomics has been attracting attention in recent years as an objective method for diagnosing schizophrenia. In this study, we analyzed 378 metabolites in the serum of schizophrenia patients using capillary electrophoresis‐ and liquid chromatography‐time‐of‐flight mass spectrometry. Using multivariate analysis with the orthogonal partial least squares method, we observed significantly higher levels of alanine, glutamate, lactic acid, ornithine, and serine and significantly lower levels of urea, in patients with chronic schizophrenia compared to healthy controls. Additionally, levels of fatty acids (15:0), (17:0), and (19:1), cis‐11‐eicosenoic acid, and thyroxine were significantly higher in patients with acute psychosis than in those in remission. Moreover, we conducted a systematic review of comprehensive metabolomics studies on schizophrenia over the last 20 years and observed consistent trends of increase in some metabolites such as glutamate and glucose, and decrease in citrate in schizophrenia patients across several studies. Hence, we provide substantial evidence for metabolic biomarkers in schizophrenia patients through our metabolomics study.

In this study, we analyzed 378 metabolites in the serum of schizophrenia patients using CE and LC‐TOFMS. With a systematic review, here we provide substantial evidence for metabolic biomarkers in schizophrenia patients through our metabolomics study.

Non-Targeted LC-MS Metabolomics Approach towards an Authentication of the Geographical Origin of Grain Maize (Zea mays L.) Samples

Safety along the food and feed supply chain is an emerging topic and closely linked to the ability to analytical trace the geographical origin of food or feed. In this study, ultra-performance liquid chromatography coupled with electrospray ionization quadrupole-time-of-flight mass spectrometry was used to trace back the geographical origin of 151 grain maize (Zea mays L.) samples from seven countries using a high resolution non-targeted metabolomics approach. Multivariate data analysis and univariate statistics were used to identify promising marker features related to geographical origin. Classification using only 20 selected markers with the Random Forest algorithm led to 90.5% correctly classified samples with 100 times repeated 10-fold cross-validation. The selected markers were assigned to the class of triglycerides, diglycerides and phospholipids. The marker set was further evaluated for its ability to separate between one sample class and the rest of the dataset, yielding accuracies above 89%. This demonstrates the high potential of the non-polar metabolome to authenticate the geographic origin of grain maize samples. Furthermore, this suggests that focusing on only a few lipids with high potential for grain maize authentication could be a promising approach for later transfer of the method to routine analysis.

Bacterial precursors and unsaturated long-chain fatty acids are biomarkers of North-Atlantic deep-sea demosponges

Sponges produce distinct fatty acids (FAs) that (potentially) can be used as chemotaxonomic and ecological biomarkers to study endosymbiont-host interactions and the functional ecology of sponges. Here, we present FA profiles of five common habitat-building deep-sea sponges (class Demospongiae, order Tetractinellida), which are classified as high microbial abundance (HMA) species. Geodia hentscheli, G. parva, G. atlantica, G. barretti, and Stelletta rhaphidiophora were collected from boreal and Arctic sponge grounds in the North-Atlantic Ocean. Bacterial FAs dominated in all five species and particularly isomeric mixtures of mid-chain branched FAs (MBFAs, 8- and 9-Me-C_16:0 and 10- and 11-Me-C_18:0) were found in high abundance (together ≥ 20% of total FAs) aside more common bacterial markers. In addition, the sponges produced long-chain linear, mid- and a(i)-branched unsaturated FAs (LCFAs) with a chain length of 24‒28 C atoms and had predominantly the typical Δ^5,9 unsaturation, although the Δ^9,19 and (yet undescribed) Δ^11,21 unsaturations were also identified. G. parva and S. rhaphidiophora each produced distinct LCFAs, while G. atlantica, G. barretti, and G. hentscheli produced similar LCFAs, but in different ratios. The different bacterial precursors varied in carbon isotopic composition (δ¹³C), with MBFAs being more enriched compared to other bacterial (linear and a(i)-branched) FAs. We propose biosynthetic pathways for different LCFAs from their bacterial precursors, that are consistent with small isotopic differences found in LCFAs. Indeed, FA profiles of deep-sea sponges can serve as chemotaxonomic markers and support the concept that sponges acquire building blocks from their endosymbiotic bacteria.

Yarrowia lipolytica as an Oleaginous Platform for the Production of Value-Added Fatty Acid-Based Bioproducts

The microbial fermentation process has been used as an alternative pathway to the production of value-added natural products. Of the microorganisms, Yarrowia lipolytica, as an oleaginous platform, is able to produce fatty acid-derived biofuels and biochemicals. Nowadays, there are growing progresses on the production of value-added fatty acid-based bioproducts in Y. lipolytica. However, there are fewer reviews performing the metabolic engineering strategies and summarizing the current production of fatty acid-based bioproducts in Y. lipolytica. To this end, we briefly provide the fatty acid metabolism, including fatty acid biosynthesis, transportation, and degradation. Then, we introduce the various metabolic engineering strategies for increasing bioproduct accumulation in Y. lipolytica. Further, the advanced progress in the production of fatty acid-based bioproducts by Y. lipolytica, including nutraceuticals, biofuels, and biochemicals, is summarized. This review will provide attractive thoughts for researchers working in the field of Y. lipolytica.

The fabrication of a novel polyacrylonitrile/reduced graphene oxide-amino-halloysite/bimetallic metal–organic framework electrospun nanofiber adsorbent for the ultrasonic-assisted thin-film microextraction of fatty acid methyl esters in dairy products with gas chromatography-flame ionization detection

In this work, electrospun polyacrylonitrile/reduced graphene oxide-amino-halloysite/bimetallic metal–organic framework (PAN/rGO-amino-HNT/Co_0.5Zn_0.5(MeIm)₂) nanofiber film was synthesized and investigated as a novel adsorbent for the ultrasonic-assisted thin-film microextraction (UA-TFME) of fatty acid methyl esters (FAMEs), including palmitic methyl ester (PAME), oleic methyl ester (OAME), stearic methyl ester (SAME), and linoleic methyl ester (LAME), from dairy products. The hybrid nanocomposite was obtained via bonding halloysite nanotubes to reduced graphene oxide, followed by loading with bimetallic metal–organic frameworks. The determination of FAMEs with nanofiber film was performed in two stages of desorption and absorption where, initially, the analytes were adsorbed onto the nanofiber film and then desorbed with organic solvent. In this study, ultrasound was used for both the adsorption and desorption stages. The advantages of ultrasonication are extensive, overcoming the shortcomings of conventional techniques in terms of energy consumption and solvent use, allowing a shorter treatment time with a low cost of implementation. Based on PAN/rGO-amino-HNT/Co_0.5Zn_0.5(MeIm)₂ thin film, a microextraction-gas chromatography-flame ionization detection (TFME-GC-FID) method was developed. Experimental parameters affecting the extraction and desorption steps were optimized. The desorption parameters, including desorption time and the properties of the desorption solvent, were investigated one factor at a time. Then, effective parameters in the adsorption step were optimized using a Box–Behnken design and Design-Expert 7 software. Under the optimal conditions, the method detection limits (S/N = 3) were in the range of 0.03–0.06 μg L⁻¹ and the limits of quantification (S/N = 10) were within 0.11–0.23 μg L⁻¹. The relative standard deviations for intra-day and inter-day precision were 2.4–4.7% and 2.6–3.4%, respectively. In the present work, the UA-TFME method was successfully applied for the quantification of fatty acid methyl esters in dairy products (milk, yogurt, cheese, yogurt soda and butter samples) for the first time. The fatty acids were transesterified using standard procedures and were subjected to UA-TFME treatment prior to GC-FID determination. The developed method possesses the advantages of simplicity, rapidity, cost-effectiveness, sensitivity, and non-invasiveness.

Electrospun polyacrylonitrile/reduced graphene oxide-amino-halloysite/bimetallic metal–organic framework nanofiber film was synthesized and successfully applied to the ultrasonic-assisted thin-film microextraction (UA-TFME) of fatty acid methyl esters from dairy products.

Comparative Lipidomics of Different Yeast Species Associated to Drosophila suzukii

Yeasts constitute a dietary source for the spotted wing drosophila (SWD) and produce compounds that attract these flies. The study of the chemical composition of the yeast communities associated with SWD should therefore help to understand the relationship between the biology of the insect and the yeast's metabolism. In the present study, the lipidome of five yeast species isolated from grapes infested by SWD (three Hanseniaspora uvarum strains, Candida sp., Issatchenkia terricola, Metschnikowia pulcherrima and Saccharomycopsis vini) and a laboratory strain of Saccharomyces cerevisiae was explored using an untargeted approach. Additionally, the lipid profile of two species, S. cerevisiae and H. uvarum, which were reported to elicit different responses on SWD flies based on feeding and behavioral trials, was compared with a chemical enrichment approach. Overall, 171 lipids were annotated. The yeast species could be distinguished from each other based on their lipid profile, except for the three strains of H. uvarum, which were very similar to each other. The chemical enrichment analysis emphasized diversities between S. cerevisiae and H. uvarum, that could not be detected based on their global lipid profile. The information concerning differences between species in their lipidome may be of interest to future entomological studies concerning the yeast-insect interaction and could help to explain the responses of SWD to diverse yeast species.

The Effect of One Anastomosis Gastric Bypass on Branched-Chain Fatty Acid and Branched-Chain Amino Acid Metabolism in Subjects with Morbid Obesity

BACKGROUND

Subjects with morbid obesity have low levels of serum branched-chain fatty acids (BCFAs), which correlate inversely with insulin resistance, hypertriglyceridemia, and inflammation. Recent evidence suggests BCFAs are produced during branched-chain amino acid (BCAA) catabolism in human adipose tissue. Elevated concentrations of BCAAs are associated with insulin resistance.

OBJECTIVES

In this single-center study, we evaluated the effect of one anastomosis gastric bypass (OAGB) on circulating BCFA and BCAA. Moreover, we determined the expression of genes involved in BCAA catabolism in adipose tissue of patients with obesity and lean controls.

METHODS

Fasting levels of BCFAs and BCAAs were determined by gas and liquid chromatography, respectively, coupled with mass spectrometry, in 50 patients with morbid obesity before and 6-9 months after surgery, and in 32 lean controls. Visceral and subcutaneous adipose tissue (VAT and SAT, respectively) biopsies were collected at baseline to determine mRNA levels for enzymes involved in BCAA catabolism.

RESULTS

Before surgery, patients with obesity had lower BCFAs and greater BCAAs than control subjects. OAGB increased BCFA and decreased BCAA levels. Insulin resistance (assessed by HOMA) correlated inversely with BCFAs and positively with BCAAs. Expression of genes involved in BCAA catabolism in VAT (but not SAT) was lower in patients with obesity than in lean controls.

CONCLUSIONS

OAGB-induced weight loss increases circulating BCFAs and decreases circulating BCAAs in patients with morbid obesity, perhaps by altering BCAA catabolism in VAT. We speculate that this shift may be related to the improvement in insulin sensitivity after surgery.

Analysis of Malassezia Lipidome Disclosed Differences Among the Species and Reveals Presence of Unusual Yeast Lipids

Malassezia yeasts are lipid dependent and part of the human and animal skin microbiome. However, they are also associated with a variety of dermatological conditions and even cause systemic infections. How these yeasts can live as commensals on the skin and switch to a pathogenic stage has long been a matter of debate. Lipids are important cellular molecules, and understanding the lipid metabolism and composition of Malassezia species is crucial to comprehending their biology and host-microbe interaction. Here, we investigated the lipid composition of Malassezia strains grown to the stationary phase in a complex Dixon medium broth. In this study, we perform a lipidomic analysis of a subset of species; in addition, we conducted a gene prediction analysis for the detection of lipid metabolic proteins. We identified 18 lipid classes and 428 lipidic compounds. The most commonly found lipids were triglycerides (TAG), sterol (CH), diglycerides (DG), fatty acids (FAs), phosphatidylcholine (PC), phosphatidylethanolamine (PE), ceramides, cholesteryl ester (CE), sphingomyelin (SM), acylcarnitine, and lysophospholipids. Particularly, we found a low content of CEs in Malassezia furfur, atypical M. furfur, and Malassezia pachydermatis and undetectable traces of these components in Malassezia globosa, Malassezia restricta, and Malassezia sympodialis. Remarkably, uncommon lipids in yeast, like diacylglyceryltrimethylhomoserine and FA esters of hydroxyl FAs, were found in a variable concentration in these Malassezia species. The latter are bioactive lipids recently reported to have antidiabetic and anti-inflammatory properties. The results obtained can be used to discriminate different Malassezia species and offer a new overview of the lipid composition of these yeasts. We could confirm the presence and the absence of certain lipid-biosynthesis genes in specific species. Further analyses are necessary to continue disclosing the complex lipidome of Malassezia species and the impact of the lipid metabolism in connection with the host interaction.

Phosphoinositide Profile of the Mouse Retina

Phosphoinositides are known to play multiple roles in eukaryotic cells. Although dysregulation of phosphoinositide metabolism in the retina has been reported to cause visual dysfunction in animal models and human patients, our understanding of the phosphoinositide composition of the retina is limited. Here, we report a characterization of the phosphoinositide profile of the mouse retina and an analysis of the subcellular localization of major phosphorylated phosphoinositide forms in light-sensitive photoreceptor neurons. Using chromatography of deacylated phosphatidylinositol headgroups, we established PI(4,5)P₂ and PI(4)P as two major phosphorylated phosphoinositides in the retina. Using high-resolution mass spectrometry, we revealed 18:0/20:4 and 16:0/20:4 as major fatty-acyl chains of retinal phosphoinositides. Finally, analysis of fluorescent phosphoinositide sensors in rod photoreceptors demonstrated distinct subcellular distribution patterns of major phosphoinositides. The PI(4,5)P₂ reporter was enriched in the inner segments and synapses, but was barely detected in the light-sensitive outer segments. The PI(4)P reporter was mostly found in the outer and inner segments and the areas around nuclei, but to a lesser degree in the synaptic region. These findings provide support for future mechanistic studies defining the biological significance of major mono- (PI(4)P) and bisphosphate (PI(4,5)P₂) phosphatidylinositols in photoreceptor biology and retinal health.

BIOTECHNOLOGICAL POTENTIAL OF PSEUDOKIRCHNERIELLA SUBCAPITATA, SCENEDESMUS SPINOSUS, AND SCENEDESMUS ACUMINATUS

Microalgae are promising alternatives to sequestration of carbon and reduction of environmental problems, e.g. the greenhouse effect and industrial water pollution. Depending on the growth conditions, microalgae can differ in their metabolism products, leading them to grow at different rates. Intracellular reactions and nutritional requirements from cell metabolism, as well as biomass composition, may vary in function of the temperature. In this study, the biotechnological potential of three microalgae strains from the species was evaluated in terms of growth, biomass composition, fatty acid profile, and chlorophyll and carotenoids contents. Each of the three species demonstrated different potential depending on their metabolisms: Scenedesmus spinosus presented fastest growth and had the highest protein content (52.99%), Pseudokirchneriella subcapitata presented the highest content of lipid extracted (26.51%), and Scenedesmus acuminatus showed increased production of chlorophyll (5.25 mg l–1) and carotenoid (1.02 mg l–1) pigments.

Modulation of hepatic lipidome by rhodioloside in high-fat diet fed apolipoprotein E knockout mice

BACKGROUND

Rhodioloside is a glucoside of tyrosol isolated from Rhodiola rosea. However, its regulating effect on hepatic dyslipidemia of atherogenic mice has rarely been studied.

PURPOSE

The specific aims of current study included to clarify lipidomic perturbation in liver tissues of apolipoprotein E deficient (apoE^-/-) mice fed with high-fat diet, and to examine the effects of rhodioloside against atherosclerosis and dyslipidemia.

STUDY DESIGN

The comparisons of hepatic lipidome were executed between wide type (WT) mice fed with normal diet (NDC) and apoE^-/- mice fed with high-fat diet (Model), WT mice fed with high-fat diet (HFDC) versus the model mice, as well as the model mice versus rhodioloside-treated atherosclerotic mice.

METHODS

Ultra high performance liquid chromatography coupled with a Q exactive hybrid quadrupole-orbitrap mass spectrometry (UPLC-MS/MS) was employed to provide an unbiased and simultaneous measurement of individual lipid species in liver tissues.

RESULTS

Multivariate statistical analysis derived from LC-MS spectra revealed that high-fat diet and apoE deficiency caused a series of disturbances on glyerolipid metabolism, glycerophospholipid metabolism and sphingolipid metabolism. Rhodioloside administration showed atheroprotective effects on the apoE^-/- mice with regulating the levels of 1 phosphatidylcholine, 2 phosphatidylserines, 5 alkyldiacylglycerols and 3 alkenyldiacylglycerols back to normal. In particular, PC (4:0/15:0) was positively associated with high-density lipoprotein cholesterol in blood, both of which could be ameliorated by rhodioloside.

CONCLUSION

Our results identified the abnormal hepatic lipids in atherosclerosis progression that could efficiently improved by rhodioloside. These lipids contributed to biological understanding of atherogenic dyslipidemia in liver and could also served as sensitive indicators for drug target screening.

Novel Non-methylene-Interrupted Dienoic and Trienoic Fatty Acids with a Terminal Double Bond in Ovaries of the Limpet Cellana toreuma

In this study, to obtain further information on the structural diversity of non-methylene-interrupted (NMI) fatty acids (FA) in the gonads of the limpet Cellana toreuma, previously unreported minor NMI FA, fractionated by argentation thin-layer chromatography (TLC), in the ovaries were characterized by gas chromatography-mass spectrometry (GC-MS) analysis of their 3-pyridylcarbinol derivatives. As a result, five novel NMI FA were identified as 5,14-pentadecadienoic acid (15: 2Δ5,14), 5,9,18-nonadecatrienoic acid (19:3Δ5,9,18), 5,9,20-heneicosatrienoic acid (21:3Δ5,9,20), 7,13,20-heneicosatrienoic acid (21:3Δ7,13,20), and 5,9,22-tricosatrienoic acid (23:3Δ5,9,22). Possible biosynthetic pathways for these FA are also discussed in relation to structural variations of NMI FA regioisomers. This study clearly reinforces the findings of our previous works with structurally diverse NMI FA with a terminal double bond.

Analysis of Phospholipids, Lysophospholipids, and Their Linked Fatty Acyl Chains in Yellow Lupin Seeds (Lupinus luteus L.) by Liquid Chromatography and Tandem Mass Spectrometry

Hydrophilic interaction liquid chromatography (HILIC) and electrospray ionization (ESI) coupled to either Fourier-transform (FT) orbital-trap or linear ion-trap tandem mass spectrometry (LIT-MS/MS) was used to characterize the phospholipidome of yellow lupin (Lupinus luteus) seeds. Phosphatidylcholines (PC) were the most abundant species (41 ± 6%), which were followed by lyso-forms LPC (30 ± 11%), phosphatidylethanolamines (PE, 13 ± 4%), phosphatidylglycerols (PG, 5.1 ± 1.7%), phosphatidic acids (PA, 4.9 ± 1.8%), phosphatidylinositols (PI, 4.7 ± 1.1%), and LPE (1.2 ± 0.5%). The occurrence of both isomeric forms of several LPC and LPE was inferred by a well-defined fragmentation pattern observed in negative ion mode. An unprecedented characterization of more than 200 polar lipids including 52 PC, 42 PE, 42 PA, 35 PG, 16 LPC, 13 LPE, and 10 PI, is reported. The most abundant fatty acids (FA) as esterified acyl chains in PL were 18:1 (oleic), 18:2 (linoleic), 16:0 (palmitic), and 18:3 (linolenic) with relatively high contents of long fatty acyl chains such as 22:0 (behenic), 24:0 (lignoceric), 20:1 (gondoic), and 22:1 (erucic). Their occurrence was confirmed by reversed-phase (RP) LC-ESI-FTMS analysis of a chemically hydrolyzed sample extract in acid conditions at 100 °C for 45 min.

De novo Biosynthesis of Odd-Chain Fatty Acids in Yarrowia lipolytica Enabled by Modular Pathway Engineering

Microbial oils are regarded as promising alternatives to fossil fuels as concerns over environmental issues and energy production systems continue to mount. Odd-chain fatty acids (FAs) are a type of valuable lipid with various applications: they can serve as biomarkers, intermediates in the production of flavor and fragrance compounds, fuels, and plasticizers. Microorganisms naturally produce FAs, but such FAs are primarily even-chain; only negligible amounts of odd-chain FAs are generated. As a result, studies using microorganisms to produce odd-chain FAs have had limited success. Here, our objective was to biosynthesize odd-chain FAs de novo in Yarrowia lipolytica using inexpensive carbon sources, namely glucose, without any propionate supplementation. To achieve this goal, we constructed a modular metabolic pathway containing seven genes. In the engineered strain expressing this pathway, the percentage of odd-chain FAs out of total FAs was higher than in the control strain (3.86 vs. 0.84%). When this pathway was transferred into an obese strain, which had been engineered to accumulate large amounts of lipids, odd-chain fatty acid production was 7.2 times greater than in the control (0.05 vs. 0.36 g/L). This study shows that metabolic engineering research is making progress toward obtaining efficient cell factories that produce odd-chain FAs.

Lipidomic profiling of non-mineralized dental plaque and biofilm by untargeted UHPLC-QTOF-MS/MS and SWATH acquisition

Dental plaque is a structurally organized biofilm which consists of diverse microbial colonies and extracellular matrix. Its composition may change when pathogenic microorganisms become dominating. Therefore, dental biofilm or plaque has been frequently investigated in the context of oral health and disease. Furthermore, its potential as an alternative matrix for analytical purposes has also been recognized in other disciplines like archeology, food sciences, and forensics. Thus, a careful in-depth characterization of dental plaque is worthwhile. Most of the conducted studies focused on the screening of microbial populations in dental plaque. Their lipid membranes, on the other hand, may significantly impact substance (metabolite) exchange within microbial colonies as well as xenobiotics uptake and incorporation into teeth. Under this umbrella, a comprehensive lipidomic profiling for determination of lipid compositions of in vivo dental plaque samples and of in vitro cultivated biofilm as surrogate matrix to be used for analytical purposes has been performed in this work. An untargeted lipidomics workflow utilizing a ultra-high-performance liquid chromatography (UHPLC)-quadrupole-time-of-flight (QTOF) platform together with comprehensive SWATH (sequential window acquisition of all theoretical fragment ion mass spectra) acquisition and compatible software (MS-DIAL) that comprises a vast lipid library has been adopted to establish an extensive lipidomic fingerprint of dental plaque. The main lipid components in dental plaque were identified as triacylglycerols, followed by cholesterol, cholesteryl esters as well as diacylglycerols, and various phospholipid classes. In vivo plaque is a rare matrix which is usually available in very low amounts. When higher quantities for specific research assays are required, efficient ways to produce an appropriate surrogate matrix are mandatory. A potential surrogate matrix substituting dental plaque was prepared by cultivation of in vitro biofilm from saliva and similarities and differences in the lipidomics profile to in vivo plaque were mapped by statistical evaluation post-analysis. It was discovered that most lipid classes were highly elevated in the in vitro biofilm samples, in particular diacylglycerols, phosphatidylglycerols, and phosphatidylethanolamines (PEs). Furthermore, an overall shift from even-chain lipid species to odd-chain lipids was observed in the cultivated biofilms. On the other hand, even-chain phosphatidylcholines (PCs), lysoPCs, cholesteryl esters, and cholesterol-sulfate were shown to be specifically increased in plaque samples.

Short-Term Effect of One-Anastomosis Gastric Bypass on Essential Fatty Acids in the Serum of Obese Patients

One-anastomosis gastric bypass is a promising type of bariatric surgery, but it may lead to a deficiency in important nutrients, such as fatty acids. The short-term effects of one-anastomosis gastric bypass on serum fatty acids have not been studied thus far. Therefore, the aim of this study was to determine the effect of one-anastomosis gastric bypass on serum fatty acid composition two weeks after surgery. This study included 38 patients who underwent one-anastomosis gastric bypass as surgical treatment for morbid obesity. Serum fatty acid composition was analyzed before and two weeks after surgery using gas chromatography–mass spectrometry. We observed a decrease in essential polyunsaturated fatty acids (p < 0.001 for linolenic acid and p < 0.001 for linoleic acid) and odd-chain fatty acids (p = 0.004) in the serum of obese patients shortly after a one-anastomosis gastric bypass. Considering the benefits of the aforementioned fatty acids for human health, the implementation of a fatty-acid-rich diet or the use of supplementation may be recommended for patients immediately after one-anastomosis gastric bypass.

Valuable Fatty Acids in Bryophytes-Production, Biosynthesis, Analysis and Applications

Bryophytes (mosses, liverworts and hornworts) often produce high amounts of very long-chain polyunsaturated fatty acids (vl-PUFAs) including arachidonic acid (AA, 20:4 Δ5,8,11,14) and eicosapentaenoic acid (EPA, 20:5 Δ5,8,11,14,17). The presence of vl-PUFAs is common for marine organisms such as algae, but rarely found in higher plants. This could indicate that bryophytes did not lose their marine origin completely when they landed into the non-aqueous environment. Vl-PUFA, especially the omega-3 fatty acid EPA, is essential in human diet for its benefits on healthy brain development and inflammation modulation. Recent studies are committed to finding new sources of vl-PUFAs instead of fish and algae oil. In this review, we summarize the fatty acid compositions and contents in the previous studies, as well as the approaches for qualification and quantification. We also conclude different approaches to enhance AA and EPA productions including biotic and abiotic stresses.

Using 1-propanol to significantly enhance the production of valuable odd-chain fatty acids by Rhodococcus opacus PD630

Odd-chain fatty acids (OCFAs) have been reported to possess pharmacological activity and have been used in the manufacture of agricultural and industrial chemicals. We here provided a new method to increase the OCFAs content in oil produced by Rhodococcus opacus PD630 through addition of 1-propanol to the fermentation media. The OCFAs in oil of R. opacus PD630 are primarily pentadecanoic acid (C15:0), heptadecanoic acid (C17:0) and heptadecenoic acid (C17:1). After adding 0.5-1.5% (v/v) 1-propanol, the production of oil increased from 1.27 g/L to 1.31-1.61 g/L, and the OCFAs content in oil increased by 46.7-55.1%. Metabolic intermediates determination and transcriptome analysis revealed that R. opacus assimilated 1-propanol through methylmalonyl-CoA pathway. When the nitrogen source was limited, propionyl-CoA was converted to propionyl-acyl carrier protein (ACP) which could be used as primer during the elongation of fatty acid synthesis. Then OCFAs were produced when odd number of propionyl-ACP was incorporated in the cycles of fatty acid synthesis.

New Discorhabdin Alkaloids from the Antarctic Deep-Sea Sponge Latrunculia biformis

The sponge genus Latrunculia is a prolific source of discorhabdin type pyrroloiminoquinone alkaloids. In the continuation of our research interest into this genus, we studied the Antarctic deep-sea sponge Latrunculia biformis that showed potent in vitro anticancer activity. A targeted isolation process guided by bioactivity and molecular networking-based metabolomics yielded three known discorhabdins, (-)-discorhabdin L (1), (+)-discorhabdin A (2), (+)-discorhabdin Q (3), and three new discorhabdin analogs (-)-2-bromo-discorhabdin D (4), (-)-1-acetyl-discorhabdin L (5), and (+)-1-octacosatrienoyl-discorhabdin L (6) from the MeOH-soluble portion of the organic extract. The chemical structures of 1-6 were elucidated by extensive NMR, HR-ESIMS, FT-IR, [α]_D, and ECD (Electronic Circular Dichroism) spectroscopy analyses. Compounds 1, 5, and 6 showed promising anticancer activity with IC₅₀ values of 0.94, 2.71, and 34.0 µM, respectively. Compounds 1-6 and the enantiomer of 1 ((+)-discorhabdin L, 1e) were docked to the active sites of two anticancer targets, topoisomerase I-II and indoleamine 2,3-dioxygenase (IDO1), to reveal, for the first time, the binding potential of discorhabdins to these proteins. Compounds 5 and 6 are the first discorhabdin analogs with an ester function at C-1 and 6 is the first discorhabdin bearing a long-chain fatty acid at this position. This study confirms Latrunculia sponges to be excellent sources of chemically diverse discorhabdin alkaloids.

Metabolomics-Based Approach for the Discrimination of Potato Varieties ( Solanum tuberosum) using UPLC-IMS-QToF

One hundred eighty-two authentic potato samples ( Solanum tuberosum) of known variety were collected from various German regions in 2016 and 2017. Samples were extracted with a liquid-liquid-extraction protocol that included isopropanol, methanol, and water in order to focus on lipophilic metabolites. The analysis of nonpolar extracts was performed using an UPLC-IMS-QToF-MS system; data sets obtained were evaluated via multivariate data analysis. A selection of 14 key metabolites with a significant difference in their abundance profiles was identified. This set of markers contained four hydroxylated glucocerebrosides, two phosphoinositols, one phosphocholine, and seven acylated sterol glucosides based on stigmasterol and β-sitosterol, which primarily enable the varietal discrimination. Fragments and neutral losses commonly appearing within one class or subclass of lipids were summarized within a new database that included ion mobility data. The performance of the approach was verified with twenty-nine commercial potato samples.

Ultra-performance liquid chromatography-mass spectrometry for precise fatty acid profiling of oilseed crops

Oilseed crops are one of the most important sources of vegetable oils for food and industry. Nutritional and technical properties of vegetable oil are primarily determined by its fatty acid (FA) composition. The content and composition of FAs in plants are commonly determined using gas chromatography-mass spectrometry (GS-MS) or gas chromatography-flame ionization detection (GC-FID) techniques. In the present work, we applied ultra-performance liquid chromatography-mass spectrometry (UPLC-MS) technique to FA profiling of sunflower and rapeseed seeds and compared this method with the GC-FID technique. GC-FID detected 11 FAs in sunflower and 13 FAs in rapeseed, while UPLC-MS appeared to be more sensitive, detecting about 2.5 times higher numbers of FAs in both plants. In addition to even-chain FAs, UPLC-MS was able to detect odd-chain FAs. The longest FA detected using GC-FID was an FA with 24 carbon atoms, whereas UPLC-MS could reveal the presence of longer FAs with the tails of up to 28 carbon atoms. Based on our results, we may conclude that UPLC-MS has great potential to be used for the assessment of FA profiles of oil crops.

Altered metabolites in guinea pigs with allergic asthma after acupoint sticking therapy: New insights from a metabolomics approach

BACKGROUND

Clinical evidence gathered in Chinese communities suggested that acupoint sticking therapy could be an alternative treatment for asthma-related diseases. However, its underlying mechanism is still poorly understood.

AIM/HYPOTHESIS

In this study, we aimed to investigate the mechanism of the anti-inflammatory effect of acupoint sticking application with 'Treatment of Winter Disease in Summer' (TWDS) prescription by using metabolomics.

METHODS

Allergic asthma in guinea pig was sensitized and challenged by ovalbumin (OVA). Histopathological evaluation of the lung tissue was performed by hematoxylin and eosin (H&E) staining and Masson's trichrome staining. The levels of Th2 cytokine and IgE level in serum were measured using enzyme-linked immunoassay (ELISA). The mRNA expression levels of IL-4, IL-5, IL-13 and orosomucoid-like 3 (ORMDL3) were measured using quantitative reverse transcription polymerase chain reaction (RT-qPCR). Proteins of NF-κB signaling pathway were measured using western blot. The serum metabolomics profiles were obtained by using ultra-performance liquid chromatography combined with electrospray ionization quadrupole time-of-flight mass spectrometry (UPLC-ESI-QTOF-MS).

RESULTS

The overall results confirmed that AST with TWDS prescription had a significant protective effect against OVA-induced allergic asthma in guinea pig. This treatment not only attenuated airway inflammation and collagen deposition in the airway, but also decreased the levels of IL-4, IL-5, IL-13 and IgE in serum. In addition, metabolomics results indicated that metabolisms of phospholipid, sphingolipid, purine, amino acid and level of epinephrine were restored back to the normal control level. Moreover, results of the gene expression of ORMDL3 in lung tissues indicated that AST using TWDS could alter the sphingolipid metabolism. Further western blotting analysis also showed that its anti-inflammatory mechanism was by decreasing the phosphorylation of p65 and IκB.

CONCLUSION

The study demonstrated that metabolomics provides a better understanding of the actions of TWDS acupoint sticking therapy on OVA-induced allergic asthma.

Both Dietary Fatty Acids and Those Present in the Cecotrophs Contribute to the Distinctive Chemical Characteristics of New Zealand Rabbit Milk Fat

The relationship between the fatty acid (FA) profile of cecotrophs and that of the milk fat was evaluated in nine multiparous New Zealand does during the first 12 days of lactation. Milk samples were obtained manually on days 6, 8, 10, and 12 postpartum and cecotrophs and feces were collected on days 7, 9, and 11 postpartum. The FA profiles of feed, milk, cecotrophs, and feces were determined using gas chromatography. The principal FA found in rabbits' milk were 8:0, 10:0, 16:0, 18:1 cis-9, and 18:2 n-6. Bacteria-derived FA found in the milk fat included branched FA from 14 to 16 carbons, and 18:1 trans. Two isomers of conjugated linoleic acid (CLA) were also present, namely cis-9,trans-11 (0.09 ± 0.006 mol%) and trans-10,cis-12 (0.06 ± 0.01 mol%). The content of total FA in the cecotrophs was the 1.10 ± 0.08 mg/100 mg freeze-dried sample, with 2.50 ± 0.83 mol% 18:1 trans-11. Significant correlations between cecotroph and milk FA profiles were found for numerous FA, and those with correlation coefficients greater than 0.90 were 12:0, 14:0, 15:0, 16:0, 18:0, 18:1 trans-6/8, 18:1 trans-9, 18:1 cis-9, 18:2 n-6, 18:3 n-3, 20:1 cis-9, 20:2 n-6, and 22:0. Cecum biohydrogenation processes were evident based on the greater content of saturated FA (p = 0.008) found (54.46 ± 4.37 mol%) in the cecotrophs relative to that in feces (43.08 ± 4.37 mol%). Under conditions of the present study, the milk FA profile was influenced by the FA profile of diet and the cecotrophs consumed by lactating does.