scholarly journals A bacterial biosynthetic pathway for methylated furan fatty acids

2020 ◽  
Vol 295 (29) ◽  
pp. 9786-9801 ◽  
Author(s):  
Rachelle A. S. Lemke ◽  
Stephanie M. Olson ◽  
Kaitlin Morse ◽  
Steven D. Karlen ◽  
Alan Higbee ◽  
...  

Fatty acids play many important roles in cells and also in industrial processes. Furan fatty acids (FuFAs) are present in the lipids of some plant, fish, and microbial species and appear to function as second messengers in pathways that protect cells from membrane-damaging agents. We report here the results of chemical, genetic, and synthetic biology experiments to decipher the biosynthesis of the monomethylated FuFA, methyl 9-(3-methyl-5-pentylfuran-2-yl) nonanoate (9M5-FuFA), and its dimethyl counterpart, methyl 9-(3,4-dimethyl-5-pentylfuran-2-yl) nonanoate (9D5-FuFA), in two α-proteobacteria. Each of the steps in FuFA biosynthesis occurs on pre-existing phospholipid fatty acid chains, and we identified pathway intermediates and the gene products that catalyze 9M5-FuFA and 9D5-FuFA synthesis in Rhodobacter sphaeroides 2.4.1 and Rhodopseudomonas palustris CGA009. One previously unknown pathway intermediate was a methylated diunsaturated fatty acid, (10E,12E)-11-methyloctadeca-10,12-dienoic acid (11Me-10t,12t-18:2), produced from (11E)-methyloctadeca-11-enoic acid (11Me-12t-18:1) by a newly identified fatty acid desaturase, UfaD. We also show that molecular oxygen (O2) is the source of the oxygen atom in the furan ring of 9M5-FuFA, and our findings predict that an O2-derived oxygen atom is incorporated into 9M5-FuFA via a protein, UfaO, that uses the 11Me-10t,12t-18:2 fatty acid phospholipid chain as a substrate. We discovered that R. palustris also contains a SAM-dependent methylase, FufM, that produces 9D5-FuFA from 9M5-FuFA. These results uncover the biochemical sequence of intermediates in a bacterial pathway for 9M5-FuFA and 9D5-FuFA biosynthesis and suggest the existence of homologs of the enzymes identified here that could function in FuFA biosynthesis in other organisms.

2020 ◽  
Vol 16 ◽  
Author(s):  
Luxia Zheng ◽  
Xiong Shen ◽  
Yingchun Wang ◽  
Jian Liang ◽  
Mingming Xu ◽  
...  

Background: Phospholipids are widely used in food and pharmaceutical industry as functional excipients. In spite of the many analytical methods reported, there are very limited reports concerning systematic research and comparison of phospholipid excipients. Objective: To present a comprehensive evaluation of commercial natural phospholipid excipients (CNPEs). Methods: Seventeen batches of CNPEs from five manufacturing enterprises, isolated either from soybean or egg yolk, were investigated. The content and composition of phospholipids, fatty acids and sterols as a whole were considered as the evaluative index of CNPEs. Eight kinds of phospholipids were determined by supercritical fluid chromatography (SFC), twenty-one kinds of fatty acids were determined by gas chromatography (GC) after boron trifluoride-methanol derivatization, and nine kinds of sterols were determined by high performance liquid chromatography (HPLC) after separation and derivatization of the unsaponifiable matter. Cluster analysis was employed for classification and identification of the CNPEs. Results: The results showed that each kind of CNPEs had its characteristic content and composition of phospholipids, fatty acids and sterols. Seventeen batches of samples were divided into eight groups in cluster analysis. CNPEs of the same type from different source (soybean or egg yolk) or enterprises presented different content and composition of phospholipids, fatty acids and sterols. Conclusion: Each type of CNPEs had its characteristic content and composition of phospholipid, fatty acid and sterol. The compositions of phospholipid, fatty acid and sterol as a whole can be applied as an indicator of the quality and characteristics for CNPEs.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Zolian S. Zoong Lwe ◽  
Ruth Welti ◽  
Daniel Anco ◽  
Salman Naveed ◽  
Sachin Rustgi ◽  
...  

AbstractUnderstanding the changes in peanut (Arachis hypogaea L.) anther lipidome under heat stress (HT) will aid in understanding the mechanisms of heat tolerance. We profiled the anther lipidome of seven genotypes exposed to ambient temperature (AT) or HT during flowering. Under AT and HT, the lipidome was dominated by phosphatidylcholine (PC), phosphatidylethanolamine (PE), and triacylglycerol (TAG) species (> 50% of total lipids). Of 89 lipid analytes specified by total acyl carbons:total carbon–carbon double bonds, 36:6, 36:5, and 34:3 PC and 34:3 PE (all contain 18:3 fatty acid and decreased under HT) were the most important lipids that differentiated HT from AT. Heat stress caused decreases in unsaturation indices of membrane lipids, primarily due to decreases in highly-unsaturated lipid species that contained 18:3 fatty acids. In parallel, the expression of Fatty Acid Desaturase 3-2 (FAD3-2; converts 18:2 fatty acids to 18:3) decreased under HT for the heat-tolerant genotype SPT 06-07 but not for the susceptible genotype Bailey. Our results suggested that decreasing lipid unsaturation levels by lowering 18:3 fatty-acid amount through reducing FAD3 expression is likely an acclimation mechanism to heat stress in peanut. Thus, genotypes that are more efficient in doing so will be relatively more tolerant to HT.


Microbiology ◽  
2004 ◽  
Vol 150 (6) ◽  
pp. 1983-1990 ◽  
Author(s):  
Takahiro Oura ◽  
Susumu Kajiwara

Fungi, like plants, are capable of producing the 18-carbon polyunsaturated fatty acids linoleic acid and α-linolenic acid. These fatty acids are synthesized by catalytic reactions of Δ12 and ω3 fatty acid desaturases. This paper describes the first cloning and functional characterization of a yeast ω3 fatty acid desaturase gene. The deduced protein encoded by the Saccharomyces kluyveri FAD3 gene (Sk-FAD3) consists of 419 amino acids, and shows 30–60 % identity with Δ12 fatty acid desaturases of several eukaryotic organisms and 29–31 % identity with ω3 fatty acid desaturases of animals and plants. During Sk-FAD3 expression in Saccharomyces cerevisiae, α-linolenic acid accumulated only when linoleic acid was added to the culture medium. The disruption of Sk-FAD3 led to the disappearance of α-linolenic acid in S. kluyveri. These findings suggest that Sk-FAD3 is the only ω3 fatty acid desaturase gene in this yeast. Furthermore, transcriptional expression of Sk-FAD3 appears to be regulated by low-temperature stress in a manner different from the other fatty acid desaturase genes in S. kluyveri.


Biomolecules ◽  
2018 ◽  
Vol 8 (4) ◽  
pp. 144 ◽  
Author(s):  
Meraj Khan ◽  
Cecil Pace-Asciak ◽  
Jassim Al-Hassan ◽  
Mohammad Afzal ◽  
Yuan Liu ◽  
...  

Various biomolecules induce neutrophil extracellular trap (NET) formation or NETosis. However, the effect of fatty acids on NETosis has not been clearly established. In this study, we focused on the NETosis-inducing ability of several lipid molecules. We extracted the lipid molecules present in Arabian Gulf catfish (Arius bilineatus, Val) skin gel, which has multiple therapeutic activities. Gas chromatography–mass spectrometry (GC-MS) analysis of the lipid fraction-3 from the gel with NETosis-inducing activity contained fatty acids including a furanoid F-acid (F6; 12,15-epoxy-13,14-dimethyleicosa-12,14-dienoic acid) and common long-chain fatty acids such as palmitic acid (PA; C16:0), palmitoleic acid (PO; C16:1), stearic acid (SA; C18:0), and oleic acid (OA; C18:1). Using pure molecules, we show that all of these fatty acids induce NETosis to different degrees in a dose-dependent fashion. Notably, F6 induces a unique form of NETosis that is rapid and induces reactive oxygen species (ROS) production by both NADPH oxidase (NOX) and mitochondria. F6 also induces citrullination of histone. By contrast, the common fatty acids (PA, PO, SA, and OA) only induce NOX-dependent NETosis. The activation of the kinases such as ERK (extracellular signal-regulated kinase) and JNK (c-Jun N-terminal kinase) is important for long-chain fatty acid-induced NETosis, whereas, in F-acid-induced NETosis, Akt is additionally needed. Nevertheless, NETosis induced by all of these compounds requires the final chromatin decondensation step of transcriptional firing. These findings are useful for understanding F-acid- and other fatty acid-induced NETosis and to establish the active ingredients with therapeutic potential for regulating diseases involving NET formation.


2006 ◽  
Vol 131 (2) ◽  
pp. 284-289 ◽  
Author(s):  
Mauricio A. Cañoles ◽  
Randolph M. Beaudry ◽  
Chuanyou Li ◽  
Gregg Howe

Six-carbon aldehydes and alcohols formed by tomato (Lycopersicon esculentum Mill.) leaf and fruit tissue following disruption are believed to be derived from the degradation of lipids and free fatty acids. Collectively, these C-6 volatiles comprise some of the most important aroma impact compounds. If fatty acids are the primary source of tomato volatiles, then an alteration in the fatty acid composition such as that caused by a mutation in the chloroplastic omega-3-fatty acid desaturase (ω-3 FAD), referred to as LeFAD7, found in the mutant line of `Castlemart' termed Lefad7, would be reflected in the volatile profile of disrupted leaf and fruit tissue. Leaves and fruit of the Lefad7 mutant had ≈10% to 15% of the linolenic acid (18:3) levels and about 1.5- to 3-fold higher linoleic acid (18:2) levels found in the parent line. Production of unsaturated C-6 aldehydes Z-3-hexenal, Z-3-hexenol, and E-2-hexenal and the alcohol Z-3-hexenol derived from 18:3 was markedly reduced in disrupted leaf and fruit tissue of the Lefad7 mutant line. Conversely, the production of the saturated C-6 aldehyde hexanal and its alcohol, hexanol, were markedly higher in the mutant line. The shift in the volatile profile brought about by the loss of chloroplastic FAD activity in the Lefad7 line was detected by sensory panels at high significance levels (P < 0.0005) and detrimentally affected fruit sensory quality. The ratios and amounts of C-6 saturated and unsaturated aldehydes and alcohols produced by tomato were dependent on substrate levels, suggesting that practices that alter the content of linoleic and linolenic acids or change their ratios can influence tomato flavor.


2001 ◽  
Vol 67 (10) ◽  
pp. 4796-4804 ◽  
Author(s):  
Maria Alexandrino ◽  
Claudia Knief ◽  
André Lipski

ABSTRACT Deuterated styrene ([2H8]styrene) was used as a tracer in combination with phospholipid fatty acid (PLFA) analysis for characterization of styrene-degrading microbial populations of biofilters used for treatment of waste gases. Deuterated fatty acids were detected and quantified by gas chromatography-mass spectrometry. The method was evaluated with pure cultures of styrene-degrading bacteria and defined mixed cultures of styrene degraders and non-styrene-degrading organisms. Incubation of styrene degraders for 3 days with [2H8]styrene led to fatty acids consisting of up to 90% deuterated molecules. Mixed-culture experiments showed that specific labeling of styrene-degrading strains and only weak labeling of fatty acids of non-styrene-degrading organisms occurred after incubation with [2H8]styrene for up to 7 days. Analysis of actively degrading filter material from an experimental biofilter and a full-scale biofilter by this method showed that there were differences in the patterns of labeled fatty acids. For the experimental biofilter the fatty acids with largest amounts of labeled molecules were palmitic acid (16:0), 9,10-methylenehexadecanoic acid (17:0 cyclo9-10), and vaccenic acid (18:1 cis11). These lipid markers indicated that styrene was degraded by organisms with aPseudomonas-like fatty acid profile. In contrast, the most intensively labeled fatty acids of the full-scale biofilter sample were palmitic acid and cis-11-hexadecenoic acid (16:1cis11), indicating that an unknown styrene-degrading taxon was present. Iso-, anteiso-, and 10-methyl-branched fatty acids showed no or weak labeling. Therefore, we found no indication that styrene was degraded by organisms with methyl-branched fatty fatty acids, such as Xanthomonas, Bacillus,Streptomyces, or Gordonia spp.


2019 ◽  
Vol 97 (Supplement_3) ◽  
pp. 134-135
Author(s):  
Artemis P Simopoulos

Abstract Human beings evolved on a diet that was balanced in the omega-6 and omega-3 essential fatty acids to which their genes were programmed to respond. Studies on gene-nutrient interactions using methods from molecular biology and genetics have clearly shown that there are genetic differences in the population, as well as differences in the frequency of genetic variations that interact with diet and influence the growth and development of humans and animals, as well as overall health and chronic disease. Nutrigenetics refers to studies on the role of genetic variants and their response to diet. For example, persons with genetic variants in the metabolism of omega-6 and omega-3 fatty acids have different levels of arachidonic acid (AA) and eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) based on the type of genetic variant in the Fatty Acid Desaturase 1 (FADS1) and Fatty Acid Desaturase 2 (FADS2). At the same level of linoleic acid (LA) and alpha-linolenic acid (ALA) a person with a genetic variant that increases the activity of the FADS1 will have a higher AA in the red cell membrane phospholipids and a higher risk for obesity and cardiovascular disease. Nutrigenomics refers to how nutrients (diets) influence the expression of genes. For example, diets rich in omega-3 fatty acids, EPA and DHA decrease the expression of inflammatory genes and as a result decrease the risk of obesity and cardiovascular disease. Thus, through studies on Nutrigenetics/Nutrigenomics nutritional science stands at its “golden threshold” where personalized nutrition is the future, to improve an individual’s health.


2020 ◽  
pp. 1-26
Author(s):  
Yan Wang ◽  
Yiwei Tang ◽  
Ye Ji ◽  
Wenhui Xu ◽  
Naeem Ullah ◽  
...  

Abstract In this study, we analysed the effects of single nucleotide polymorphism (SNP) rs174547 (T/C) in the fatty acid desaturase 1 (FADS1) gene on long-chain polyunsaturated fatty acid levels. Four databases were searched to retrieve related literature with keywords such as fatty acid, SNP, FADS1, and rs174547. A meta-analysis of the data was performed using Stata12.0 software, including summary statistics, test for heterogeneity, evaluation of publication bias, subgroup analysis, and sensitivity analysis. The associations between rs174547 in FADS1 and seven types of fatty acids, and delta-5 (D5D) and delta-6 fatty acid desaturase (D6D) activity were assessed based on the pooled results from 11 manuscripts. A total of 3713 individuals (1529 TT and 2184 TC+CC) were included. The results demonstrated that minor C allele carriers of rs174547 had higher linoleic acid (LA; P < 0.001) and α-linolenic acid (P = 0.020) levels, lower gamma linoleic acid (GLA; P = 0.001) and arachidonic acid (P = 0.024) levels, and lower D5D (P = 0.005) and D6D (P = 0.004) activities than the TT genotype group. Stratification analysis showed that minor C allele carriers of rs174547 had higher LA and lower GLA levels and lower D6D activities in plasma (LA, P < 0.001; GLA, P < 0.001; D6D activity, P < 0.001) samples and in Asian populations (LA, P < 0.001; GLA, P = 0.001; D6D activity, P = 0.001) than the TT genotype group. In conclusion, minor C allele carriers of the SNP rs174547 were associated with decreased activity of D5D and D6D.


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