scholarly journals Microbial metabolism of amino alcohols. Biosynthetic utilization of ethanolamine for lipid synthesis by bacteria

1980 ◽  
Vol 186 (1) ◽  
pp. 13-19 ◽  
Author(s):  
S D Shukla ◽  
J M Turner

1. Ten bacteria utilizing [2-14C]ethanol-2-amine as the sole or major source of nitrogen for growth on glycerol + salts medium incorporated radioactivity into a variety of bacterial substances. A high proportion was commonly found in lipid fractions, particularly in the case of Erwinia carotovora. 2. Detailed studies of [14C]ethanolamine incorporation into lipids by five bacteria, including E. carotovora, showed that all detectable lipids were labelled. Even where phosphatidylethanolamine was the major lipid labelled, radioactivity was predominantly in the fatty acid rather than the base moiety. The labelled fatty acids were identified in each case. 3. The addition of acetate to growth media decreased the incorporation of radioactivity from ethanolamine into both fatty acid and phosphatidyl-base fragments of lipids from all the bacteria except Mycobacterium smegmatis. Experiments with [3H]ethanolamine and [14C]acetate confirmed that unlabelled acetate decreased the incorporation of both radioactive isotopes into lipids, except in the case of M. smegmatis. 4. Enzyme studies suggested one of two metabolic routes between ethanolamine and acetyl-CoA for each of four bacteria. A role for ethanolamine O-phosphate was not obligatory for the incorporation of [14C]ethanolamine into phospholipids, but correlated with CoA-independent aldehyde dehydrogenase activity.

1985 ◽  
Vol 63 (2) ◽  
pp. 85-90 ◽  
Author(s):  
Sandeep Mahajan ◽  
G. K. Khuller

Cerulenin inhibited the lipid synthesis of Mycobacterium smegmatis ATCC 607 over the range of 0.5–1.8 μg/mL with complete inhibition at 1.8 μg/mL, as monitored by [14C]glycerol incorporation into lipids. Exogenous fatty acids failed to restore the lipid synthesis at 1.8 μg/mL; however, the addition of palmitic acid to the growth medium partially restored the lipid synthesis when cerulenin concentration was decreased to 1.6 μg/mL. Fatty acid analysis of cerulenin plus palmitic acid supplemented cultures revealed that exogenously supplied fatty acid was incorporated into cellular phospholipids. Further investigations with 1.6 μg/mL of cerulenin and [14C]acetate and [32P]orthophosphoric acid showed that cerulenin inhibited the synthesis of saturated plus unsaturated fatty acids and phospholipids. Pulse–chase studies with [14C]acetate revealed decreased synthesis and degradation of each of the phospholipid components.


1976 ◽  
Vol 22 (4) ◽  
pp. 443-449 ◽  
Author(s):  
J. M. Deven ◽  
M. S. Manocha

The fatty acid composition of the total and polar lipid fractions of Choanephora cucurbitarum grown under different cultural conditions were analyzed by thin-layer and gas–liquid chromatography. It was observed that temperature, age, pH, and light influenced the degree of unsaturation, this being due mainly to changes in the γ-linolenic acid concentration. The conditions used in this study did not alter the qualitative profile of fatty acids normally present in the organism. Neither did these conditions stimulate the production of further long-chain fatty acids (C20–C26) beyond γ-linolenic acid (C18:3) as reported earlier using growth media containing glutamic acid. The fatty acid pattern of lipid fractions though the same qualitatively, differed quantitatively. The polar lipid fractions, phosphatidyl choline, phosphatidyl ethanolamine, and diphosphatidyl glycerol showed an appreciable variation in γ-linolenic acid content under different cultural conditions. The degree of unsaturation of the various lipid fractions decreased with increases in temperature, light intensity, and pH, but within each treatment the same pattern of decreasing degree of unsaturation with increasing age was observed. The significance of these observations is discussed.


Author(s):  
Lena Oksdøl Foseid ◽  
Hanne Devle ◽  
Yngve Stenstrøm ◽  
Carl Fredrik Naess-Andresen ◽  
Dag Ekeberg

A thorough analysis and comparison of the fatty acid profiles of stipe and blade from Laminaria hyperborea, a kelp species found in the northern Atlantic, is presented. Lipids were extracted and fractionated into neutral lipids, free fatty acids and polar lipids, then derivatized to fatty acid methyl esters prior to GC-MS analysis. A total of 42 fatty acids were identified and quantified, including the n-3 fatty acids α-linolenic acid, stearidonic acid and eicosapentaenoic acid. An n-6/n-3 ratio of 0.8:1 was found in blade and 3.5:1 in stipe, respectively. The ratios vary between the lipid fractions within stipe and blade, with the lowest ratio in the polar lipid fraction of blade. The fatty acid amounts are higher in blade than in stipe, and the highest amounts of n-3 fatty acids are found within the neutral lipid fractions. The amounts of polyunsaturated fatty acids are 3.4 times higher in blade than stipe. This study highlights the compositional differences between the lipid fractions of stipe and blade from L. hyperborea. The amount of polyunsaturated fatty acids, compared to saturated- and monounsaturated fatty acids, as well as the n-6/n-3-ratio, is known to influence human health. In the pharmaceutical, food, and feed industries this can be of importance for production and sale of different health products. Additionally, lipids are today among the unused by products of alginate production, exploiting this material for commercial interest should give both economical and environmental benefits.


2020 ◽  
Vol 21 (23) ◽  
pp. 9093
Author(s):  
Xinchi Zhao ◽  
Guiyan Yang ◽  
Xiaoqiang Liu ◽  
Zhongdong Yu ◽  
Shaobing Peng

Walnut (Juglans regia) is known as a promising woody oil crop with abundant polyunsaturated fatty acids in its kernel. However, the regulation mechanism of walnut oil accumulation and fatty acid metabolism is still poorly understood, which restricted the breeding and genetic improvement of high-quality oil-bearing walnuts. To reveal the molecular mechanism of walnut oil accumulation, considering the potential regulation of microRNA (miRNA) in seed development, in this study, the oil content of walnut kernel on the 80th, 100th and 120th day after flowering (DAF) was tested and the corresponding proportions are 11.51%, 40.40% and 53.20%. Between DAF of 80th~120th, the content of stearic acid and oleic acid tended to increase, but the proportion of other fatty acids tended to decrease. Meanwhile, comparative transcriptome and sRNA-seq analysis on three stages (80th, 100th and 120th DAF), found 204 conserved miRNAs and 554 novel miRNAs in walnut kernels, among which 104 key genes related to walnut oil accumulation were screened. The phospholipid:diacylglycerol acyltransferase metabolic pathway may contribute more to oil accumulation in walnut. 16 miRNA-mRNA regulatory modules related to walnut oil accumulation and fatty acid synthesis were constructed. 8 known miRNAs and 9 novel miRNAs regulate 28 genes involved in fatty acid (FA) metabolism and lipid synthesis. Among them, jre-miRn105, jre-miRn434, jre-miR477d and jre-miR156a.2 are key miRNAs that regulate walnut FA synthesis. Jre-miRn411 and jre-miR399a.1 are closely related to oil accumulation. These data provide new insights and lay the foundation for subsequent studies on walnut FA synthesis and oil accumulation.


Weed Science ◽  
1975 ◽  
Vol 23 (2) ◽  
pp. 100-104 ◽  
Author(s):  
R. E. Wilkinson ◽  
A. E. Smith

EPTC (S-ethyl dipropylthiocarbamate) (33μM) and diallate [S-(2,3-dichloroallyl)diisopropylthiocarbamate] (90μM) inhibited the incorporation of 6 mM acetate-2-14C (Ac∗) by 80% and 65%, respectively, and the incorporation of 0.5μM malonate-2-14C (Mal∗) by 32% and 26%, respectively, into the lipids of spinach (Spinacia oleraceaL.) chloroplasts. The inhibition of Ac∗or Mal∗incorporation into lipids was not observed in the presence of excess Ac∗or Mal∗, respectively. Incorporation of palmitate-1-14C and oleate-1-14C into chloroplast lipids was inhibited by EPTC and diallate. Mal∗incorporation into dienoic fatty acids was inhibited by EPTC and diallate. The concentration of EPTC and diallate inhibiting lipid synthesis falls into the physiological range of these herbicides, explains some metabolic effects of these compounds, and fits as the mode of activity of these herbicides.


1990 ◽  
Vol 68 (9) ◽  
pp. 1255-1260 ◽  
Author(s):  
V. Durocher ◽  
M. Miller ◽  
M. A. Rodriguez

Glycerolphosphate acyltransferase activity in microsomes from rat adipose tissue is shown to decrease with time upon incubation with adipose tissue cytosolic fraction. The inactivation can be prevented with serum albumin and seems to be caused by an increase in endogenous free fatty acid as a consequence of the action of cytosolic lipase(s) on the membrane lipids. Similar inactivation can be observed after short incubation of microsomes with oleic acid at micromolar concentrations. Diacylglycerol acyltransferase is also inhibited by oleic acid, although to a lesser degree. In contrast, glucose-6-phosphatase and NADPH – cytochrome reductase activities are not changed. The oleic acid effect appears to occur upon binding to the microsomal membranes and can be prevented by bovine serum albumin at protein/fatty acid molar ratios above one. These results suggest that free fatty acids may be involved in the modulation of triacylglycerol synthetic enzymes.Key words: glycerolphosphate acyltransferase, fatty acids, microsomal enzymes, lipid synthesis.


1983 ◽  
Vol 61 (6) ◽  
pp. 340-345 ◽  
Author(s):  
A. C. Wilson ◽  
R. C. Goldstein ◽  
A. R. Conn ◽  
P. T. Kuo

Lipid synthesis was studied in intestinal mucosal cells isolated from rats fed a high fat or a high sucrose diet. The cells actively incorporated 14C(1)-labeled free fatty acids into glycerolipids([1-14C]acetate was utilized for both fatty acid and cholesterol synthesis), while [14C(U)]glucose label was found in cholesterol and in the glycerol moiety of glycerolipids, but not in fatty acids. Sucrose feeding resulted in increased acetate incorporation into cholesterol, but not into fatty acids while the high fat diet markedly depressed the incorporation of acetate. In contrast, fat feeding increased both glucose and fatty acid incorporation into glycerolipids, as well as glucose incorporation into cholesterol. Using the incorporation of glucose into lipid glycerol as an estimate of the phosphatidic acid pathway, it was found that this pathway was stimulated by both fat and carbohydrate feeding. The results suggest that differences in the regulation of cholesterol and glycerolipid synthesis in the intestine compared with adipose tissue and liver may relate to the role of intestine in synthesizing lipoproteins for lipid transport.


1976 ◽  
Vol 22 (12) ◽  
pp. 1716-1719 ◽  
Author(s):  
Simon W. T. Law ◽  
David N. Burton

Fractionation of total lipid extracted from Achlya sp. at various stages of its developmental cycle revealed that in spores total lipid was composed of 62% neutral lipid, 13% phospholipid, and 25% glycolipid. After germination, the proportion of neutral lipid rose slightly after 2 h then fell sharply to 10% after 8 h, whereupon it rose to 55% of total lipid after 30 h of growth, when sporulation was completed. Conversely, phospholipid rose to 77% of total lipid after 8 h, then declined to 40% after 30 h. Glycolipid was maintained at 10–20% of total lipid throughout the life cycle after spore germination. Quantitative determination of neutral lipid components by photoreflectometry showed that triglycerides accounted for 20% of neutral lipid in spores, and free fatty acids made up 50%. During growth, the absolute levels of both components fell precipitously on germination, remained at low levels throughout vegetative growth, and rose at the time of sporulation.The fatty acid composition of total lipid, phospholipid, neutral lipid, and free fatty acid fractions extracted from vegetative and sporulating Achlya cells was determined. The principal fatty acids present in all fractions at both stages of the life cycle were hexadecanoic and octadecanoic acids. Hydroxyhexadecanoic acid, eicosatetraenoic acid, and an unidentified long-chain acid were completely absent from the phospholipids of vegetative cells, although they were found in significant quantities in lipid fractions from other stages of growth.


2004 ◽  
Vol 91 (4) ◽  
pp. 551-565 ◽  
Author(s):  
G. Demirel ◽  
A. M. Wachira ◽  
L. A. Sinclair ◽  
R. G. Wilkinson ◽  
J. D. Wood ◽  
...  

The effect of feeding n-3 PUFA on the fatty acid composition of muscle, adipose tissue and liver of lambs was investigated. Groups of eight ram lambs per breed, Suffolk×Lleyn (24kg live weight) and Scottish Blackface (18kg live weight), were each fed one of six diets containing one of three fat sources (50g fatty acids/kg DM; Megalac® (calcium soap of palm fatty acid distillate; Volac Ltd, Royston, Herts., UK) and formaldehyde-treated whole linseed (Trouw Nutrition UK, Northwich, Ches., UK) either alone or with fish oil (1:1, w/w) and either 100 or 500mg α-tocopheryl acetate/kg DM. Feed was offered ad libitum until slaughter at approximately half breed mature live weight. The type of dietary fat had no effect on intake, growth rate or feed conversion ratio. The 3·0-fold higher concentration of 18:3n-3 in the linseed compared with the Megalac® diet approximately doubled (P<0·001) the concentration in the neutral and polar lipid fractions of musculus semimembranosus and liver, and in adipose tissue it increased 2·5-fold. Feeding protected linseed also increased (P<0·001) concentrations of 20:5n-3 and 22:5n-3 in muscle polar lipids and both lipid fractions of liver. The linseed–fish oil raised the 20:5n-3 concentrations above those for the linseed diet and also increased 22:6n-3. Scottish Blackface lambs had lower concentrations of 18:3n-3 in all lipids compared with Suffolk x Lleyn lambs, but more 20:5n-3 in the polar lipids of muscle and liver. High levels of dietary vitamin E were associated with small decreases in the concentration of monounsaturated fatty acids and increases in PUFA. Linseed raised the PUFA:saturated fatty acid ratios in liver and adipose tissue but not in muscle, and improved the n-6:n-3 fatty acid ratio, as did the linseed–fish oil. Different combinations of dietary fatty acids and better protection against rumen biohydrogenation are required to improve muscle PUFA:saturated fatty acids ratios.


2008 ◽  
Vol 14 (2) ◽  
pp. 127-137 ◽  
Author(s):  
M.R. Ramírez ◽  
R. Cava

The changes of the fatty acid (FA) profile of 2 muscles Longissimus dorsi and Biceps femoris from 3 Iberian × Duroc genotypes were studied: GEN1: ♂ Iberian × ♀ Duroc1, GEN2: ♂ Duroc1 × ♀ Iberian; GEN3: ♂ Duroc2 × ♀ Iberian. GEN1 and GEN2 are reciprocal crosses while the difference between GEN2 and GEN3 is the Duroc sire line. The genotype Duroc1 was selected for the production of dry-cured meat products while the genotype Duroc2 was selected for meat production. Longissimus dorsi and Biceps femoris BF from the reciprocal cross showed similar changes in FAs profile after refrigerated storage. However, the Duroc sire line affected the FA profiles of intramuscular fat (IMF) and lipid fractions since some differences were found between GEN2 and GEN3. Meat from GEN3 had the highest level of polyunsaturated fatty acids (PUFA) in IMF and lipid fractions as well as the lowest rate of plasmalogens in polar lipid fraction. After storage, meat from GEN3 showed an increase of long chain PUFA in free fatty acids fraction and the highest increase in the ratio DMA/FA [(dimethylacetals/FAs) × 100] after the refrigerated storage, which was indicative of a higher deterioration of this genotype. Therefore, the crossbreeding of Iberian pigs with Duroc selected genotypes (Duroc2) could affect the changes in the FAs profile of meat under refrigerated storage.


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