Temperature-induced differences in growth rate and fatty acid composition in two strains of Escherichia coli 15T−

1978 ◽  
Vol 24 (10) ◽  
pp. 1277-1280
Author(s):  
John L. Crowe ◽  
James E. Urban
Keyword(s):  
Escherichia Coli ◽  
Growth Rate ◽  
Fatty Acid Composition ◽  
Fatty Acid ◽  
Acid Composition ◽  
Unsaturated Fatty Acid ◽  
Growth Temperature ◽  
Doubling Time ◽  
Fatty Acid Ratio ◽  
Acid Ratio

The saturated/unsaturated fatty acid ratio of Escherichia coli 15T− decreases almost threefold as growth temperature decreases from 43 to 27 °C, whereas the ratio of a fast-growing mutant derived from 15T− changes only half as much. Strain 15T− experiences a 2.4-fold change in doubling time across this temperature range, but doubling time in the mutant changes 3.3-fold.

Effects on animal performance and fat composition of two fat concentrates in diets for growing-fattening bulls

1991 ◽  
Vol 53 (3) ◽  
pp. 315-320 ◽  
Author(s):  
A. Clinquart ◽  
L. Istasse ◽  
I. Dufrasne ◽  
A. Mayombo ◽  
C. van Eenaeme ◽  
...  
Keyword(s):  
Fatty Acid Composition ◽  
Fatty Acid ◽  
Acid Composition ◽  
Unsaturated Fatty Acid ◽  
Unsaturated Fatty Acids ◽  
Fatty Acid Ratio ◽  
Ether Extract ◽  
Acid Ratio ◽  
Soya Oil ◽  
Perirenal Fat

AbstractTwo experiments were carried out with growing-fattening bulls, offered a fattening diet based on concentrate and supplemented with soya oil or steam-flaked linseed. Soya oil (200 g/kg) was mixed with middlings (800 g/kg). Linseed (500 g/kg) and whole barley (500 g/kg) were steam flaked. The fat incorporation resulted in an increase of the ether extract content from 26·5 g/kg dry matter to about 45 g/kg. The incorporation of soya oil increased the average daily gain (P> 0·05). The saturated: unsaturated fatty acid ratio was reduced in perirenal fat due to an increase of oleic acid and a reduction of stearic acid. The inclusion of steam-treated linseed resulted in a lower slaughter weight (P< 0·05) and a shorter fattening period (P> 0·05). The fatty acid composition of perirenal fat was affected significantly: the concentrations of oleic, linoleic and linolenic acid were increased and the concentrations of myristic, palmitic and stearic acids were reduced. This resulted in a reduced saturated: unsaturated fatty acid ratio.In a third experiment, samples of the two fat concentrates were incubated in nylon bags in the rumen. The ether extract disappearance was high with both concentrates. Furthermore, the fatty acid composition was altered to a large extent for soya oil while large proportions of unsaturated fatty acids were still present with steam-flaked linseed.

Effect of carbon source on growth rate and phospholipid composition of Escherichia coli 15T− and an unsaturated fatty acid auxotroph

1981 ◽  
Vol 27 (12) ◽  
pp. 1283-1289 ◽  
Author(s):  
James E. Urban ◽  
W. E. Klopfenstein ◽  
K. Ahmad ◽  
J. D. Baines
Keyword(s):  
Escherichia Coli ◽  
Growth Rate ◽  
Fatty Acid Composition ◽  
Oleic Acid ◽  
Fatty Acid ◽  
Carbon Source ◽  
Acid Composition ◽  
Doubling Time ◽  
Phospholipid Composition ◽  
Acid Supplementation

Escherichia coli 15T− was grown with glucose, succinic acid, aspartic acid, oleic acid, and oleic plus aspartic acids as carbon sources, and a fatty acid auxotroph derived from 15T− was grown on oleic acid and oleic plus aspartic acids. The doubling time, phospholipid composition, phosphorus content, and the fatty acid composition of the phospholipids of cells in each of the media were determined. In all cases, phosphatidylethanolamine was the major phospholipid present; but with 15T− its concentration was inversely proportional to the doubling time in unsupplemented media. With the auxotroph the phosphatidylethanolamine concentration was essentially unchanged with growth. Total lipid phosphorus was inversely proportional to doubling time, an effect particularly evident with the auxotroph. Without oleic acid supplementation, the major effects of carbon source on fatty acid composition are decreases in the content of palmitoleic acid and increases in the content of cis-9,10-methylene hexadecanoic acid as growth rate decreases. Oleic acid supplementation elevated 18:1 fatty acid content in both 15T− and the auxotroph.

scholarly journals Maternal dietary 22: 6n-3 is more effective than 18: 3n-3 in increasing the 22: 6n-3 content in phospholipids of glial cells from neonatal rat brain

2005 ◽  
Vol 93 (5) ◽  
pp. 601-611 ◽  
Author(s):  
Raffick A. R. Bowen ◽  
Michael T. Clandinin
Keyword(s):  
Fatty Acid Composition ◽  
Fatty Acid ◽  
Glial Cell ◽  
Acid Composition ◽  
Glial Cells ◽  
Maternal Diet ◽  
Fatty Acid Ratio ◽  
Whole Brain ◽  
Rat Pups ◽  
Acid Ratio

One of the debates in infant nutrition concerns whether dietary 18: 3n-3 (linolenic acid) can provide for the accretion of 22: 6 n-3 (docosahexaenoic acid, DHA) in neonatal tissues. The objective of the present study was to determine whether low or high 18: 3 n-3 v. preformed 22: 6 n-3 in the maternal diet enabled a similar 22: 6 n-3 content in the phosphatidylcholine (PC), phosphatidylethanolamine (PE), phosphatidylinositol (PI) and phosphatidylserine (PS) of glial cells from whole brain (cerebrum and cerebellum) of 2-week-old rat pups. At parturition, the dams were fed semi-purified diets containing either increasing amounts of 18: 3 n-3 (18: 2 n-6 to 18: 3 n-3 fatty acid ratio of 7·8: 1, 4·4: 1 or 1: 1), preformed DHA, or preformed 20: 4 n-6 (arachidonic acid)+DHA. During the first 2 weeks of life, the rat pups from the respective dams received only their dam's milk. The fatty acid composition of the pups' stomach contents (dam's milk) and phospholipids from glial cells were quantified. The 20: 4n-6 and 22: 6 n-3 content in the stomach from rat pups at 2 weeks of age reflected the fatty acid composition of the dam's diet. The 20: 4n-6 content of PE and PS in the glial cells was unaffected by maternal diet treatments. Preformed 22: 6 n-3 in the maternal diet increased the 22: 6 n-3 content of glial cell PE and PS compared with maternal diets providing an 18: 2n-6 to 18: 3 n-3 fatty acid ratio of 7·8: 1, 4·4: 1 or 1: 1 (P<0·0001). There was no significant difference in the 20: 4 n-6 and 22: 6 n-3 content of glial cell PC and PI among maternal diet treatments. It was concluded that maternal dietary 22: 6n-3 is more effective than low or high levels of maternal dietary 18: 3 n-3 at increasing the 22: 6 n-3 content in PE and PS of glial cells from the whole brain of rat pups at 2 weeks of age. The findings from the present study have important implications for human infants fed infant formulas that are devoid of 22: 6 n-3.

Sign in / Sign up

Export Citation Format

Share Document