The effect of temperature and other growth conditions on the fatty acid composition of Escherichia coli

1981 ◽  
Vol 27 (8) ◽  
pp. 835-840 ◽  
Author(s):  
James T. McGarrity ◽  
John B. Armstrong
Keyword(s):  
Escherichia Coli ◽  
Fatty Acids ◽  
Fatty Acid Composition ◽  
Fatty Acid ◽  
Acid Composition ◽  
Exponential Growth ◽  
Growth Conditions ◽  
Cyclopropane Fatty Acid ◽  
Cyclopropane Fatty Acids ◽  
K 12

During exponential growth, strain AW405 of Escherichia coli K-12 did not regulate the fatty acid composition of its lipids in response either to temperature or to the addition of NaCl, KCl, or MgCl2 to the medium. Growth was severely restricted at temperatures below 21 °C. Differential scanning calorimetry (DSC) of the isolated lipids from a culture with a typical exponential-phase composition yielded a broad transition, extending from approximately 0 to 33 °C, with a midpoint at 19 °C.During late stages of growth, the fatty acid composition changed. The percentage of palmitic acid increased and cyclopropane fatty acids replaced some of the equivalent unsaturated fatty acids. The increase in palmitate seemed largely independent of growth conditions, whereas the increase in the cyclopropane fatty acids was stimulated by the addition of salts or sucrose. Cultures grown in the presence of sucrose also had higher cyclopropane fatty acid levels during exponential growth. DSC of lipids from a sucrose culture, in which the compositional changes were most pronounced, yielded a much narrower transition with a midpoint at 27 °C.

Advanced Gas Chromatographic–Mass Spectrometric Studies for Identification of the Cellular Octadecenoate Isomers and Changes of Fatty Acid Composition Induced by Ethanol Stress in Escherichia coli and Escherichia coli O157:H7

2007 ◽  
Vol 70 (3) ◽  
pp. 616-622 ◽  
Author(s):  
KUO-LONG KU ◽  
JUI-LONG CHIOU ◽  
FANG-CHI LIU ◽  
ROBIN Y.-Y. CHIOU
Keyword(s):  
Escherichia Coli ◽  
Fatty Acids ◽  
Fatty Acid Composition ◽  
Fatty Acid ◽  
Acid Composition ◽  
Capillary Column ◽  
Cellular Fatty Acid ◽  
Submerged Cultivation ◽  
Ethanol Stress ◽  
E Coli

Ethanol can be introduced to foods of various origins and is commonly used for surface disinfection. Low concentrations of residual ethanol may provide an opportunity for pathogens to adapt and grow. Change of cellular fatty acid composition is one of adaptation mechanisms enabling bacteria to grow under varied stresses. Since instrumental analyses of bacterial octadecenoate isomers are sophisticated, gas chromatographic analyses of the isomers, namely trans-9-octadecenoate, trans-11-octadecenoate, cis-9-octadecenoate, and cis-11-octadecenoate, and ethanol-induced formation of trans-9-octadecenoate in Escherichia coli and E. coli O157:H7 were intensively investigated. When an HP-1, a nonpolar capillary column, was used for gas chromatographic analyses of 28 authentic bacterial acid methyl esters, resolution was satisfied for all fatty acid components except trans-9-octadecenoate and cis-11-octadecenoate, being overlapped. When the column was replaced by an RTx-2330, a polar capillary column, all of the above-mentioned octadecenoate isomers were resolved. When cells of E. coli and E. coli O157:H7 were harvested after submerged cultivation (30°C, 150 rpm) in tryptic soy broth and tryptic soy broth supplemented with 5% ethanol at early stationary phase and subjected to cellular fatty acid analyses by using an HP-1 and RTx-2330 coupled with a mass detector, 12 fatty acids, i.e., trans-9-octadecenoate, 5 saturated fatty acids, 2 cyclopropane fatty acids and 4 cisunsaturated fatty acids, were identified. Individual fatty acid contents varied depending on nature of fatty acid, strain of E. coli, and supplement of ethanol. As affected by ethanol stress for both E. coli strains, contents of trans-9-octadecenoate increased, whereas contents of cyc-9,10-methylene octadecanoate (cyc-9,10-19:0) decreased significantly (P < 0.05). Apparently, both E. coli strains have rendered necessary fatty acid adaptation to survive and grow under ethanol stress.

scholarly journals The Response of Campylobacter jejuni to Low Temperature Differs from That of Escherichia coli

2009 ◽  
Vol 75 (19) ◽  
pp. 6292-6298 ◽  
Author(s):  
Rebecca-Ayme Hughes ◽  
Kathy Hallett ◽  
Tristan Cogan ◽  
Mike Enser ◽  
Tom Humphrey
Keyword(s):  
Escherichia Coli ◽  
Fatty Acid Composition ◽  
Fatty Acid ◽  
Low Temperature ◽  
Heat Resistance ◽  
Campylobacter Jejuni ◽  
Acid Composition ◽  
Cold Exposure ◽  
E Coli ◽  
K 12

ABSTRACT Human infection with Campylobacter jejuni is often associated with the consumption of foods that have been exposed to both chilling and high temperatures. Despite the public health importance of this pathogen, little is known about the effects of cold exposure on its ability to survive a subsequent heat challenge. This work examined the effect of rapid exposure to chilling, as would occur in poultry processing, on the heat resistance at 56°C of two C. jejuni strains, 11168 and 2097e48, and of Escherichia coli K-12. Unlike E. coli K-12, whose cold-exposed cells showed increased sensitivity to 56°C, such exposure had only a marginal effect on subsequent heat resistance in C. jejuni. This may be explained by the finding that during rapid chilling, unlike E. coli cells, C. jejuni cells are unable to alter their fatty acid composition and do not adapt to cold exposure. However, their unaltered fatty acid composition is more suited to survival when cells are exposed to high temperatures. This hypothesis is supported by the fact that in C. jejuni, the ratio of unsaturated to saturated fatty acids was not significantly different after cold exposure, but it was in E. coli. The low-temperature response of C. jejuni is very different from that of other food-borne pathogens, and this may contribute to its tolerance to further heat stresses.

Platelet Aggregation in Finnish Men and Its Relation to Fatty Acids in Platelets, Plasma and Adipose Tissue

1985 ◽  
Vol 54 (03) ◽  
pp. 563-569 ◽  
Author(s):  
M K Salo ◽  
E Vartiainen ◽  
P Puska ◽  
T Nikkari
Keyword(s):  
Fatty Acids ◽  
Adipose Tissue ◽  
Fatty Acid Composition ◽  
Fatty Acid ◽  
Platelet Aggregation ◽  
Acid Composition ◽  
Saturated Fatty Acids ◽  
Free Living ◽  
Ω3 Fatty Acids ◽  
Induced Aggregation

SummaryPlatelet aggregation and its relation to fatty acid composition of platelets, plasma and adipose tissue was determined in 196 randomly selected, free-living, 40-49-year-old men in two regions of Finland (east and southwest) with a nearly twofold difference in the IHD rate.There were no significant east-southwest differences in platelet aggregation induced with ADP, thrombin or epinephrine. ADP-induced platelet secondary aggregation showed significant negative associations with all C20-C22 ω3-fatty acids in platelets (r = -0.26 - -0.40) and with the platelet 20: 5ω3/20: 4ω 6 and ω3/ ω6 ratios, but significant positive correlations with the contents of 18:2 in adipose tissue (r = 0.20) and plasma triglycerides (TG) (r = 0.29). Epinephrine-induced aggregation correlated negatively with 20: 5ω 3 in plasma cholesteryl esters (CE) (r = -0.23) and TG (r = -0.29), and positively with the total percentage of saturated fatty acids in platelets (r = 0.33), but had no significant correlations with any of the ω6-fatty acids. Thrombin-induced aggregation correlated negatively with the ω3/6ω ratio in adipose tissue (r = -0.25) and the 20: 3ω6/20: 4ω 6 ratio in plasma CE (r = -0.27) and free fatty acids (FFA) (r = -0.23), and positively with adipose tissue 18:2 (r = 0.23) and 20:4ω6 (r = 0.22) in plasma phospholipids (PL).The percentages of prostanoid precursors in platelet lipids, i. e. 20: 3ω 6, 20: 4ω 6 and 20 :5ω 3, correlated best with the same fatty acids in plasma CE (r = 0.32 - 0.77) and PL (r = 0.28 - 0.74). Platelet 20: 5ω 3 had highly significant negative correlations with the percentage of 18:2 in adipose tissue and all plasma lipid fractions (r = -0.35 - -0.44).These results suggest that, among a free-living population, relatively small changes in the fatty acid composition of plasma and platelets may be reflected in significant differences in platelet aggregation, and that an increase in linoleate-rich vegetable fat in the diet may not affect platelet function favourably unless it is accompanied by an adequate supply of ω3 fatty acids.

scholarly journals A conjunction of sn-2 fatty acids and overall fatty acid composition combined with chemometric techniques increase the effectiveness of lard detection in fish feed

2021 ◽  
pp. 104308
Author(s):  
Mohamed Haniff Hanafy Idris ◽  
Yanty Noorzianna Manaf ◽  
Mohd Nasir Mohd Desa ◽  
Amalia Mohd Hashim ◽  
Muhamad Shirwan Abdullah Sani ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Fatty Acid Composition ◽  
Fatty Acid ◽  
Acid Composition ◽  
Fish Feed ◽  
Chemometric Techniques

scholarly journals Effect of Nitrogen Fertilisation and Inoculation with Bradyrhizobium japonicum on the Fatty Acid Profile of Soybean (Glycine max (L.) Merrill) Seeds

Agronomy ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 941
Author(s):  
Ewa Szpunar-Krok ◽  
Anna Wondołowska-Grabowska ◽  
Dorota Bobrecka-Jamro ◽  
Marta Jańczak-Pieniążek ◽  
Andrzej Kotecki ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Fatty Acid Composition ◽  
Fatty Acid ◽  
Acid Composition ◽  
Bradyrhizobium Japonicum ◽  
Field Experiments ◽  
Fatty Acid Content ◽  
Soybean Seeds ◽  
Oilseed Crop ◽  
Soybean Cultivars

Soybean is a valuable protein and oilseed crop ranked among the most significant of the major crops. Field experiments were carried out in 2016–2019 in South-East Poland. The influence of soybean cultivars (Aldana, Annushka), nitrogen fertilizer (0, 30, 60 kg∙ha−1 N) and inoculation with B. japonicum (control, HiStick® Soy, Nitragina) on the content of fatty acids (FA) in soybean seeds was investigated in a three-factorial experiment. This study confirms the genetic determinants of fatty acid composition in soybean seeds and their differential accumulation levels for C16:0, C16:1, C18:1n9, C18:2, C18:3, and C20:0 as well saturated (SFA), monounsaturated (MUFA), and polyunsaturated (PUFA) fatty acids. Increasing the rate from 30 to 60 kg ha−1 N did not produce the expected changes, suggesting the use of only a “starter” rate of 30 kg ha−1 N. Inoculation of soybean seeds with a strain of Bradyrhizobium japonicum (HiStick® Soy, BASF, Littlehampton, UK and Nitragina, Institute of Soil Science and Plant Cultivation–State Research Institute, Puławy, Poland) is recommended as it will cause a decrease in SFA and C16:0 acid levels. This is considered nutritionally beneficial as its contribution to total fatty acids determines the hypercholesterolemic index, and it is the third most accumulated fatty acid in soybean seeds. The interaction of cultivars and inoculation formulation on fatty acid content of soybean seeds was demonstrated. An increase in the value of C16:0 content resulted in a decrease in the accumulation of C18:1, C18:2, and C18:3 acids. The content of each decreased by almost one unit for every 1% increase in C16:0 content. The dominant effect of weather conditions on the FA profile and C18:2n6/C18:3n3 ratio was demonstrated. This suggests a need for further evaluation of the genetic progress of soybean cultivars with respect to fatty acid composition and content under varying habitat conditions.

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