scholarly journals Triacylglycerol and phytyl ester synthesis inSynechocystissp. PCC6803

2020 ◽  
Vol 117 (11) ◽  
pp. 6216-6222 ◽  
Author(s):  
Mohammed Aizouq ◽  
Helga Peisker ◽  
Katharina Gutbrod ◽  
Michael Melzer ◽  
Georg Hölzl ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Acyl Carrier Protein ◽  
Sequence Similarity ◽  
Wax Esters ◽  
Oxygenic Photosynthesis ◽  
Wax Ester ◽  
Ester Synthesis ◽  
Acyltransferase Activity ◽  
Storage Lipids ◽  
Triacylglycerol Synthesis

Cyanobacteria are unicellular prokaryotic algae that perform oxygenic photosynthesis, similar to plants. The cells harbor thylakoid membranes composed of lipids related to those of chloroplasts in plants to accommodate the complexes of photosynthesis. The occurrence of storage lipids, including triacylglycerol or wax esters, which are found in plants, animals, and some bacteria, nevertheless remained unclear in cyanobacteria. We show here that the cyanobacteriumSynechocystissp. PCC6803 accumulates both triacylglycerol and wax esters (fatty acid phytyl esters). Phytyl esters accumulate in higher levels under abiotic stress conditions. The analysis of an insertional mutant revealed that the acyltransferase slr2103, with sequence similarity to plant esterase/lipase/thioesterase (ELT) proteins, is essential for triacylglycerol and phytyl ester synthesis inSynechocystis. The recombinant slr2103 enzyme showed acyltransferase activity with phytol and diacylglycerol, thus producing phytyl esters and triacylglycerol. Acyl-CoA thioesters were the preferred acyl donors, while acyl-ACP (acyl carrier protein), free fatty acids, or galactolipid-bound fatty acids were poor substrates. The slr2103 protein sequence is unrelated to acyltransferases from bacteria (AtfA) or plants (DGAT1, DGAT2, PDAT), and therefore establishes an independent group of bacterial acyltransferases involved in triacylglycerol and wax ester synthesis. The identification of the geneslr2103responsible for triacylglycerol synthesis in cyanobacteria opens the possibility of using prokaryotic photosynthetic cells in biotechnological applications.

scholarly journals Phosphatidylcholine increases the secretion of triacylglycerol-rich lipoproteins by CaCo-2 cells

1996 ◽  
Vol 314 (2) ◽  
pp. 569-575 ◽  
Author(s):  
Satya N. MATHUR ◽  
Ella BORN ◽  
Shubha MURTHY ◽  
F. Jeffrey FIELD
Keyword(s):  
Cholesteryl Ester ◽  
Secretory Pathway ◽  
Cholesterol Acyltransferase ◽  
Lipid Synthesis ◽  
Brefeldin A ◽  
Mrna Levels ◽  
Ester Synthesis ◽  
Acyltransferase Activity ◽  
Apob Mrna ◽  
Triacylglycerol Synthesis

The regulation of lipid synthesis and secretion by phosphatidylcholine was investigated in CaCo-2 cells grown on semipermeable filters. In cells incubated with 1 mM taurocholate and 100–500 μM phosphatidylcholine, cholesteryl ester synthesis was decreased, triacylglycerol synthesis was increased modestly, whereas phospholipid synthesis was unaffected. Acyl-CoA–cholesterol acyltransferase activity was decreased secondary to a decrease in the substrate (cholesterol) supply. The basolateral secretion of newly synthesized triacylglycerol and triacylglycerol mass was significantly increased by phosphatidylcholine, whereas cellular triacylglycerol mass decreased. This effect was not specific for phosphatidylcholine as phosphatidylethanolamine and phosphatidylserine also increased the secretion of newly synthesized triacylglycerols. Dioleoylphosphatidylcholine was as effective as egg phosphatidylcholine in increasing triacylglycerol transport. Dipalmitoylphosphatidylcholine, in contrast, was without effect. Phosphatidylcholine also increased the basolateral secretion of apolipoprotein B (apoB) mass without altering apoB mRNA levels. Disruption of the Golgi apparatus by monensin or brefeldin A prevented the increase in apoB secretion by phosphatidylcholine. Compared with microsomes prepared from control cells, those from cells incubated with phosphatidylcholine contained more newly synthesized apoB. The percentage of new synthesized apoB isolated from the lumen of microsomes (as an estimate of apoB destined for secretion), however, was similar in the two preparations. Thus in CaCo-2 cells incubated with phosphatidylcholine, the transport of apoB and triacylglycerols is increased whereas cholesteryl ester synthesis and secretion are decreased. A normally functioning secretory pathway is required for phosphatidylcholine to increase triacylglycerol-rich lipoprotein secretion.

Fatty acid characterization of lipid fractions from blubber biopsies of sperm whales Physeter macrocephalus located around the Azores

2008 ◽  
Vol 88 (6) ◽  
pp. 1109-1115 ◽  
Author(s):  
M.J. Walton ◽  
M.A. Silva ◽  
S.M. Magalhães ◽  
R. Prieto ◽  
R.S. Santos
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Fatty Alcohols ◽  
Wax Esters ◽  
Wax Ester ◽  
Physeter Macrocephalus ◽  
Fatty Acid Profiles ◽  
Sperm Whales ◽  
Ecological Data ◽  
Mammal Species

Fatty acid profiles of blubber have been shown previously to provide information on stock structure and sex differences. Generally the predominant blubber lipid of marine mammal species is triacylglycerol (fatty acids linked to glycerol) and previous studies have focused on this lipid class. But in some species such as the sperm whales the predominant lipid is wax esters (fatty acids linked to fatty alcohols) although triacylglycerols are also present. In this study the fatty acids and fatty alcohols of these lipid classes were characterized and the fatty acid profiles compared in order to assess their potential to provide qualitative ecological data.Biopsy samples were obtained from 40 whales found in seas around the Azores achipelago during the period 2002–2003. The samples contained about 10% lipid of which 70% was wax ester and 11% triacylglycerol. The fatty acids of the triacylglycerols and wax esters were respectively approximately 19% and 16% saturated, 74% and 80% monounsaturated and 5% and 3% polyunsaturated with the main contributors being 18:1n-9, 16:1n-7 and 16:0. The alcohols of the wax esters were mainly either saturated or monounsaturated with the main contributors being 18:1n-9 (40%) and 16:0 (22%). No statistically significant differences in profiles were found between different island groups, between sexes or between years of sampling. In future studies there would not appear to be any apparent benefits over total lipid in examining each of the fatty acid classes of sperm whale blubber separately.

scholarly journals Purification, Characterization, and Potential Bacterial Wax Production Role of an NADPH-Dependent Fatty Aldehyde Reductase from Marinobacter aquaeolei VT8

2009 ◽  
Vol 75 (9) ◽  
pp. 2758-2764 ◽  
Author(s):  
Bradley D. Wahlen ◽  
Whitney S. Oswald ◽  
Lance C. Seefeldt ◽  
Brett M. Barney
Keyword(s):  
Fatty Acids ◽  
Specific Activity ◽  
Aromatic Aldehydes ◽  
Wax Esters ◽  
Wax Ester ◽  
Fatty Aldehyde ◽  
Aldehyde Reductase ◽  
Specific Chemical ◽  
Marinobacter Aquaeolei ◽  
Long Chain

ABSTRACT Wax esters, ester-linked fatty acids and long-chain alcohols, are important energy storage compounds in select bacteria. The synthesis of wax esters from fatty acids is proposed to require the action of a four-enzyme pathway. An essential step in the pathway is the reduction of a fatty aldehyde to the corresponding fatty alcohol, although the enzyme responsible for catalyzing this reaction has yet to be identified in bacteria. We report here the purification and characterization of an enzyme from the wax ester-accumulating bacterium Marinobacter aquaeolei VT8, which is a proposed fatty aldehyde reductase in this pathway. The enzyme, a 57-kDa monomer, was expressed in Escherichia coli as a fusion protein with the maltose binding protein on the N terminus and was purified to near homogeneity by using amylose affinity chromatography. The purified enzyme was found to reduce a number of long-chain aldehydes to the corresponding alcohols coupled to the oxidation of NADPH. The highest specific activity was observed for the reduction of decanal (85 nmol decanal reduced/min/mg). Short-chain and aromatic aldehydes were not substrates. The enzyme showed no detectable catalysis of the reverse reaction, the oxidation of decanol by NADP+. The mechanism of the enzyme was probed with several site-specific chemical probes. The possible uses of this enzyme in the production of wax esters are discussed.

scholarly journals Neutral Lipid Biosynthesis in Engineered Escherichia coli: Jojoba Oil-Like Wax Esters and Fatty Acid Butyl Esters

2006 ◽  
Vol 72 (2) ◽  
pp. 1373-1379 ◽  
Author(s):  
Rainer Kalscheuer ◽  
Tim Stöveken ◽  
Heinrich Luftmann ◽  
Ursula Malkus ◽  
Rudolf Reichelt ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Fatty Acids ◽  
Fatty Acid ◽  
Neutral Lipids ◽  
Wax Esters ◽  
Wax Ester ◽  
Jojoba Oil ◽  
E Coli ◽  
Butyl Esters ◽  
Long Chain

ABSTRACT Wax esters are esters of long-chain fatty acids and long-chain fatty alcohols which are of considerable commercial importance and are produced on a scale of 3 million tons per year. The oil from the jojoba plant (Simmondsia chinensis) is the main biological source of wax esters. Although it has a multitude of potential applications, the use of jojoba oil is restricted, due to its high price. In this study, we describe the establishment of heterologous wax ester biosynthesis in a recombinant Escherichia coli strain by coexpression of a fatty alcohol-producing bifunctional acyl-coenzyme A reductase from the jojoba plant and a bacterial wax ester synthase from Acinetobacter baylyi strain ADP1, catalyzing the esterification of fatty alcohols and coenzyme A thioesters of fatty acids. In the presence of oleate, jojoba oil-like wax esters such as palmityl oleate, palmityl palmitoleate, and oleyl oleate were produced, amounting to up to ca. 1% of the cellular dry weight. In addition to wax esters, fatty acid butyl esters were unexpectedly observed in the presence of oleate. The latter could be attributed to solvent residues of 1-butanol present in the medium component, Bacto tryptone. Neutral lipids produced in recombinant E. coli were accumulated as intracytoplasmic inclusions, demonstrating that the formation and structural integrity of bacterial lipid bodies do not require specific structural proteins. This is the first report on substantial biosynthesis and accumulation of neutral lipids in E. coli, which might open new perspectives for the biotechnological production of cheap jojoba oil equivalents from inexpensive resources employing recombinant microorganisms.

Evaluation of thioesterases from Acinetobacter baylyi for production of free fatty acids

2017 ◽  
Vol 63 (4) ◽  
pp. 321-329 ◽  
Author(s):  
Rahul Ukey ◽  
William E. Holmes ◽  
Rakesh Bajpai ◽  
Andrei Y. Chistoserdov
Keyword(s):  
Fatty Acids ◽  
Free Fatty Acids ◽  
Vaccenic Acid ◽  
Fold Increase ◽  
Coli Strain ◽  
Wax Ester ◽  
Acinetobacter Baylyi ◽  
E Coli ◽  
Storage Lipids ◽  
Ester Biosynthesis

Acinetobacter baylyi is one of few Gram-negative bacteria capable of accumulating storage lipids in the form of triacylglycerides and wax esters, which makes it an attractive candidate for production of lipophilic products, including biofuel precursors. Thioesterases play a significant dual role in the triacylglyceride and wax ester biosynthesis by either providing or removing acyl-CoA from this pathway. Therefore, 4 different thioesterase genes were cloned from Acinetobacter baylyi ADP1 and expressed in Escherichia coli to investigate their contribution to free fatty acids (FFAs) accumulation. Overexpression of the genes tesA′ (a leaderless form of the gene tesA) and tesC resulted in increased accumulation of FFAs when compared with the host E. coli strain. Overexpression of tesA′ showed a 1.87-fold increase in production of long-chain fatty acids (C16 to C18) over the host strain. Unlike TesC and the other investigated thioesterases, the TesA′ thioesterase also produced shorter chain FFAs (e.g., myristic acid) and unsaturated FFAs (e.g., cis-vaccenic acid (18:1Δ11)). A comparison of the remaining 3 A. baylyi ADP1 thioesterases (encoded by the tesB, tesC, and tesD genes) revealed that only the strain containing the tesC gene produced statistically higher levels of FFAs over the control, suggesting that it possesses the acyl-ACP thioesterase activity. Both E. coli strains containing the tesB and tesD genes produced levels of FFAs similar to those of the plasmid-free control E. coli strain, which indicates that TesB and TesD lack the acyl-ACP thioesterase activity.

scholarly journals Wax ester production in nitrogen-rich conditions by metabolically engineered Acinetobacter baylyi ADP1

2019 ◽  
Author(s):  
Jin Luo ◽  
Elena Efimova ◽  
Pauli Losoi ◽  
Ville Santala ◽  
Suvi Santala
Keyword(s):  
Metabolic Engineering ◽  
Isocitrate Lyase ◽  
Fatty Acyl ◽  
Wax Esters ◽  
Wax Ester ◽  
High Carbon ◽  
Acinetobacter Baylyi ◽  
Storage Lipids ◽  
Carbon Nitrogen Ratio ◽  
Nitrogen Ratio

AbstractMetabolic engineering can be used as a powerful tool to redirect cell resources towards product synthesis, also in conditions that are not optimal. An example of a synthesis pathway strongly dependent on external conditions is the production of storage lipids, which typically requires high carbon/nitrogen ratio. Acinetobacter baylyi ADP1 is known for its ability to produce industrially interesting storage lipids, namely wax esters (WEs). Here, we engineered the central carbon metabolism of A. baylyi ADP1 by deletion of the gene aceA encoding for isocitrate lyase in order to allow redirection of carbon towards WEs. The production was further enhanced by overexpression of fatty acyl-CoA reductase Acr1 in the wax ester production pathway. This strategy led to 3-fold improvement in yield (0.075 g/g glucose) and 3.15-fold improvement in titer (1.82 g/L) and productivity (0.038 g/L/h) by a simple one-stage batch cultivation with glucose as carbon source. The engineered strain accumulated up to 27% WEs of cell dry weight. The titer and cellular WE content are the highest reported to date among microbes. We further showed that the engineering strategy alleviated the inherent requirement for high carbon/nitrogen ratio and demonstrated the production of wax esters using nitrogen-rich substrates including casamino acids, yeast extract and baker’s yeast hydrolysate, which support biomass production but not WE production in wild-type cells. The study demonstrates the power of metabolic engineering in overcoming natural limitations in the production of storage lipids.

Some Details of Fatty Acids and Alcohols in the Lipids of North Atlantic Copepods

1974 ◽  
Vol 31 (11) ◽  
pp. 1812-1818 ◽  
Author(s):  
K. G. Ackman ◽  
B. A. Linke ◽  
J. Hingley
Keyword(s):  
Fatty Acids ◽  
North Atlantic ◽  
Wax Esters ◽  
Calanus Finmarchicus ◽  
Wax Ester ◽  
Plankton Sample ◽  
Low Density ◽  
Virtual Absence ◽  
Fatty Acids And Alcohols ◽  
Centropages Typicus

Fatty alcohols and fatty acids from both triglycerides and wax esters of a mixed plankton sample consisting mostly of the copepods Centropages typicus, with some Calanus finmarchicus, and a few other organisms, were compared. The alcohols were probably derived from both calanoids and emphasized alc 20:1 (19.2%) and alc 22:1 (44.9%) despite the virtual absence of the corresponding monoethylenic fatty acids. The isomer composition for monoethylenic alcohols parallels that observed for acids in clupeid depot fats and it is suggested that this particular wax ester composition is a result of low density lipids, especially alc 22:1, being deposited during heavy feeding to offset the mass from codeposition of protein and carbohydrate.

The lipid, fatty acid and fatty alcohol composition of the myctophid fish Electrona antarctica: high level of wax esters and food-chain implications

1997 ◽  
Vol 9 (3) ◽  
pp. 258-265 ◽  
Author(s):  
Charles F. Phleger ◽  
Peter D. Nichols ◽  
Patti Virtue
Keyword(s):  
Fatty Acids ◽  
Total Lipid ◽  
Dry Weight ◽  
Monounsaturated Fatty Acids ◽  
Wax Esters ◽  
Wax Ester ◽  
Lipid Fatty Acid ◽  
Myctophid Fish ◽  
High Level ◽  
Elephant Island

The myctophid, Electrona antarctica, was collected by trawl from the Elephant Island region of the Antarctic Peninsula, and from East Antarctica near 61°S and 93°W. Total lipid was higher in Elephant Island E. antarctica (whole fish, 466–585 mg g−1 dry weight) than those from Eastern Antarctica (394–459 mg g−1). Wax esters comprised 86.2–90.5% of total lipid in E. antarctica flesh. There were no significant differences between Eastern Antarctica and Elephant Island in total wax ester levels, or in levels of wax esters between different tissues analysed. Oily bones (up to 326 mg g−1 in the neurocranium) characterized E. antarctica from both locations, with wax esters as the major skeletal lipid class (67.0–87.9%, percent of lipid). The wax esters may have a buoyancy role in E. antarctica. The only substantial amount of triacylglycerols (29.4%) were found in the viscera of Elephant Island fish. The principal fatty acids of all fish analysed included the monounsaturated fatty acids 18:1(n-9) and 16:1(n-7), with lower levels of 16:0 and 14:0 saturated acids. Fatty alcohols were dominated by the saturated 16:0 and 14:0 (37.8–47.8%) and the monounsaturated 18:1(n-9) and 18:1(n-7) (38.3–59.2%). The low ratio of 22:1/20:1 alcohols observed for E. antarctica is consistent with a diet of amphipods, copepods and other items low in 22:1 alcohols.

scholarly journals Lipases of germinating jojoba seeds efficiently hydrolyze triacylglycerols and wax esters and display wax ester-synthesizing activity

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Adam Kawiński ◽  
Magdalena Miklaszewska ◽  
Szymon Stelter ◽  
Bartosz Głąb ◽  
Antoni Banaś
Keyword(s):  
Fatty Acids ◽  
Monounsaturated Fatty Acids ◽  
Fatty Alcohols ◽  
Wax Esters ◽  
In Vitro Assays ◽  
Wax Ester ◽  
Glucose Content ◽  
Esterification Reactions ◽  
Long Chain

Abstract Background Simmondsia chinensis (jojoba) is the only plant known to store wax esters instead of triacylglycerols in its seeds. Wax esters are composed of very-long-chain monounsaturated fatty acids and fatty alcohols and constitute up to 60% of the jojoba seed weight. During jojoba germination, the first step of wax ester mobilization is catalyzed by lipases. To date, none of the jojoba lipase-encoding genes have been cloned and characterized. In this study, we monitored mobilization of storage reserves during germination of jojoba seeds and performed detailed characterization of the jojoba lipases using microsomal fractions isolated from germinating seeds. Results During 26 days of germination, we observed a 60–70% decrease in wax ester content in the seeds, which was accompanied by the reduction of oleosin amounts and increase in glucose content. The activity of jojoba lipases in the seed microsomal fractions increased in the first 50 days of germination. The enzymes showed higher activity towards triacylglycerols than towards wax esters. The maximum lipase activity was observed at 60 °C and pH around 7 for triacylglycerols and 6.5–8 for wax esters. The enzyme efficiently hydrolyzed various wax esters containing saturated and unsaturated acyl and alcohol moieties. We also demonstrated that jojoba lipases possess wax ester-synthesizing activity when free fatty alcohols and different acyl donors, including triacylglycerols and free fatty acids, are used as substrates. For esterification reactions, the enzyme utilized both saturated and unsaturated fatty alcohols, with the preference towards long chain and very long chain compounds. Conclusions In in vitro assays, jojoba lipases catalyzed hydrolysis of triacylglycerols and different wax esters in a broad range of temperatures. In addition, the enzymes had the ability to synthesize wax esters in the backward reaction. Our data suggest that jojoba lipases may be more similar to other plant lipases than previously assumed.

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