The Inhibitory Action of Fatty Acids on the Growth of

Fay, J. P.; Farı́as, Ricardo N.

doi:10.1099/00221287-91-2-233

Cited by 71 publications

(39 citation statements)

References 10 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The observed degree of toxicity and morphological changes are unique to endogenous production and cannot be replicated by exogenous addition of lauric acid. Previous studies investigating the exogenous addition of 0.4% decanoic, methyldecanoic acid, or undecanoic acid have similarly observed little growth inhibition (26,27); however, much lower concentrations (0.01%) of methyldecanoic acid induced lysis of E. coli spheroplasts (27). The outer membrane of E. coli is decorated with hydrophilic lipopolysaccharides, providing a protective barrier against diffusive entry of hydrophobic compounds and completely excluding free fatty acids with 14 or more carbon chain lengths without the presence of the outer membrane fatty acid transporter FadL (11).…”

Section: Discussionmentioning

confidence: 99%

Membrane Stresses Induced by Overproduction of Free Fatty Acids in Escherichia coli

Lennen

Kruziki

Kumar

et al. 2011

Appl Environ Microbiol

138

157

View full text Add to dashboard Cite

Microbially produced fatty acids are potential precursors to high-energy-density biofuels, including alkanes and alkyl ethyl esters, by either catalytic conversion of free fatty acids (FFAs) or enzymatic conversion of acyl-acyl carrier protein or acyl-coenzyme A intermediates. Metabolic engineering efforts aimed at overproducing FFAs in Escherichia coli have achieved less than 30% of the maximum theoretical yield on the supplied carbon source. In this work, the viability, morphology, transcript levels, and protein levels of a strain of E. coli that overproduces medium-chain-length FFAs was compared to an engineered control strain. By early stationary phase, an 85% reduction in viable cell counts and exacerbated loss of inner membrane integrity were observed in the FFA-overproducing strain. These effects were enhanced in strains endogenously producing FFAs compared to strains exposed to exogenously fed FFAs. Under two sets of cultivation conditions, longchain unsaturated fatty acid content greatly increased, and the expression of genes and proteins required for unsaturated fatty acid biosynthesis were significantly decreased. Membrane stresses were further implicated by increased expression of genes and proteins of the phage shock response, the MarA/Rob/SoxS regulon, and the nuo and cyo operons of aerobic respiration. Gene deletion studies confirmed the importance of the phage shock proteins and Rob for maintaining cell viability; however, little to no change in FFA titer was observed after 24 h of cultivation. The results of this study serve as a baseline for future targeted attempts to improve FFA yields and titers in E. coli.Microbially derived free fatty acids (FFAs) are attractive intermediates for producing a wide range of high-energy-density biofuels from sustainable carbon sources, such as biomass (34). FFAs can be extracted from culture medium and catalytically converted to esters or alkanes (48, 55). Alternatively, enzymatic pathways exist for intracellular conversion to esters (42, 81), olefins (10, 59, 75), alkanes (78), or fatty aldehydes and fatty alcohols (22,81,82). These pathways can either be exploited in their native host or heterologously expressed in a genetically pliable microorganism (3). The physical and chemical properties of the resulting products are dependent on chain length and hydrophobicity; however, medium-chainlength (8-to 14-carbon) methyl esters, olefins, and alkanes exhibit many properties analogous to those of diesel and jet fuel and are therefore potential drop-in replacements (44,61).Several studies have demonstrated FFA overproduction in Escherichia coli (19,48,52,81,83). In each, the key strain modifications included overexpression of one or more cytosolic acyl-acyl carrier protein (ACP) thioesterases and deletion of fadD, or both fadD and fadE, which encode an acyl-coenzyme A (CoA) synthetase and acyl-CoA dehydrogenase, respectively. Overexpression of an acyl-ACP thioesterase depletes the level of acyl-ACP intermediates, which inhibit via feedback enzymes of fatty acid bi...

show abstract

Section: Discussionmentioning

confidence: 99%

Membrane Stresses Induced by Overproduction of Free Fatty Acids in Escherichia coli

Lennen

Kruziki

Kumar

et al. 2011

Appl Environ Microbiol

138

157

View full text Add to dashboard Cite

show abstract

“…The spectrum of antibacterial activity of FFA in vitro varies with chain length, the degree of unsaturation, the methods used to disperse the lipids, and other experimental variables (22)(23)(24)(25)(26)(41)(42)(43)(44). In general, both gram-positive and gram-negative bacteria have an equal (and low) level of sensitivity to short chain (CIO and shorter) FFA.…”

Section: Discussionmentioning

confidence: 99%

Characterization of the extracellular bactericidal factors of rat alveolar lining material.

Coonrod¹,

Lester²,

Hsu³

1984

J. Clin. Invest.

View full text Add to dashboard Cite

Abstract. The surfactant fraction (55,000-g pellet) of leukocyte-free rat bronchoalveolar lavage fluid contains factors that rapidly kill and lyse pneumococci. These factors were purified and identified biochemically by using a quantitative bactericidal test to monitor fractionation procedures. 91% of the antipneumococcal activity of rat surfactant was recovered in chloroform after extraction of rat surfactant with chloroform-methanol (Bligh-Dyer procedure). After chromatography on silicic acid with chloroform, acetone, and methanol, all detectable antibacterial activity (-80% of the initial activity) eluted with the neutral lipids in chloroform. When rechromatographed on silicic acid with hexane, hexane-chloroform, and chloroform, the antibacterial activity eluted with FFA. Thin-layer chromatography (TLC) established that the antibacterial activity was confined to the FFA fraction. Gas-liquid chromatography showed that the fatty acid fraction contained a mixture of long-chain FFA (C12 to C22) of which 66.7% were saturated and 32.4% were unsaturated. The quantity of TLC-purified FFA needed to kill 50% of 108 pneumococci under standardized conditions (one bactericidal unit) was 10.6±0.5 Ag. Purified FFA acted as detergents, causing release of [3H]choline from pneumococcal cell walls and increased bacterial cell membrane permeability, evidenced by rapid unloading of 3-0-[3H]methyl-Dglucose. FFA acting as detergents appear to account for the bactericidal and bacteriolytic activity of rat pulmonary surfactant for pneumococci.

show abstract

“…DISCUSSION Growth of gram-positive and, to a lesser extent, gram-negative bacteria is inhibited by fatty acids (Freese et al, 1973). Different fatty acids produce different inhibitory effects, depending upon their structure and chain length (Fay and Farias, 1975;Silvius and McElhatiey, 1978). In the present study, growth of M. tuberculosis H37RV was inhibited by palmitoleic and oleic acids, whereas elaidic acid acted as a growth promotor.…”

Section: Virulence Experimentsmentioning

confidence: 99%

LIPID COMPOSITION AND VIRULENCE OF MYCOBACTERIUM TUBERCULOSIS H₃₇Rv

Khuller

Taneja

Kaur

et al. 1982

Aust J Exp Biol Med

View full text Add to dashboard Cite

Summary.The total lipids increased with decrease in total phospholipids in Mycobacterium tuberculosis H37RV grown at 30° as compared to 37°, Oleic and elaidic acid supplemented to the growth medium resulted in a higher total lipid and phospholipid content, but the content was lower in cells grown in the presence of palmitoleic acid. Cellular content of mannophosphoinositides decreased, whereas that of phosphatidylethanolamine and cardiolipin increased at the lower temperature, A decrease in mannophosphoinositides and an increase in cardiolipin were noted with all fatty acid supplements; however, phosphatidylethanolamine behaved differently. The unsaturated to saturated fatty acids ratio increased at low temperature with oleic and elaidic acid supplements, but it decreased with palmitoleic acid. Cells from media supplemented with palmitoleic acid were found to be most virulent to guinea-pigs. Possible correlation of altered lipid composition and virulence of M. tubercutosis H37RV has been discussed.

show abstract

The Inhibitory Action of Fatty Acids on the Growth of

Cited by 71 publications

References 10 publications

Membrane Stresses Induced by Overproduction of Free Fatty Acids in Escherichia coli

Membrane Stresses Induced by Overproduction of Free Fatty Acids in Escherichia coli

Characterization of the extracellular bactericidal factors of rat alveolar lining material.

LIPID COMPOSITION AND VIRULENCE OF MYCOBACTERIUM TUBERCULOSIS H₃₇Rv

Contact Info

Product

Resources

About

The Inhibitory Action of Fatty Acids on the Growth of

Cited by 71 publications

References 10 publications

Membrane Stresses Induced by Overproduction of Free Fatty Acids in Escherichia coli

Membrane Stresses Induced by Overproduction of Free Fatty Acids in Escherichia coli

Characterization of the extracellular bactericidal factors of rat alveolar lining material.

LIPID COMPOSITION AND VIRULENCE OF MYCOBACTERIUM TUBERCULOSIS H37Rv

Contact Info

Product

Resources

About

LIPID COMPOSITION AND VIRULENCE OF MYCOBACTERIUM TUBERCULOSIS H₃₇Rv