Regulation of fatty acid composition of Cl. perfringens type A cells by hydrogen and hydroxyl ions

The composition of the fatty acid profiles of Cl. perfringens type A, grown on media with initial pH values from 5.5 to 9.0, was determined by the method of gas-liquid chromatography. The fatty acid profiles are stabilized in 18- to 24-h cultures. Hydrogen ions stimulate the synthesis of cyclopropane carboxylic fatty acids and "desaturase" activity; hydroxyl ions inhibit these processes. The content of saturated fatty acids in the bacteria is regulated by the initial acid-alkaline conditions of the medium. An increase in biomass accumulation under the influence of hydroxyl ions is coupled with a decrease in the energy supply of the bacteria. Possible mechanisms of the development of resistance to hydrogen and hydroxyl ions during the cultivation of Clostridia on a period growth medium are discussed.     

Role of lipids in the acid resistance of saprophytic mycobacteria]

The resistance of saprophyte mycobacteria to acids increases on a medium containing paraffin. The content of free lipids and mycolic acids in the cells of Mycobacterium convolutum assimilating the hydrocarbon increases cf. that in the cells grown on meat-peptone broth. The structure of mycolic acids was established after studying their methyl esters by mass spectrometry. The cells grown on the medium with hexadecane contain mycolic acids C32--C36, with C34- and C36-compounds prevailing and the aliphatic chain in alpha-position containing 10, 11, 12, and 14 C-atoms. The cells cultivated on meat-peptone broth contain another type of acids of high molecular weight (greater than 700).     

EFFECT OF TEMPERATURE ON THE COMPOSITION OF FATTY ACIDS IN ESCHERICHIA COLI.

Marr, Allen G. (University of California, Davis) and John L. Ingraham. Effect of temperature on composition of fatty acids in Escherichia coli. J. Bacteriol. 84:1260-1267. 1962.-Variations in the temperature of growth and in the composition of the medium alter the proportions of individual fatty acids in the lipids of Escherichia coli. As the temperature of growth is lowered, the proportion of unsaturated fatty acids (hexadecenoic and octadecenoic acids) increases. The increase in content of unsaturated acids with a decrease in temperature of growth occurs in both minimal and complex media. Cells harvested in the stationary phase contained large amounts of cyclopropane fatty acids (methylenehexadecanoic and methylene octadecanoic acids) in comparison with cells harvested during exponential growth. Cells grown in a chemostat, limited by the concentration of ammonium salts, show a much higher content of saturated fatty acids (principally palmitic acid) than do cells harvested from an exponentially-growing batch culture in the same medium. Cells grown in a chemostat, limited by the concentration of glucose, show a slightly higher content of unsaturated fatty acids than cells from the corresponding batch culture. The results do not indicate a direct relation between fatty acid composition and minimal growth temperature.     

Relationship of Cellular Fatty Acid Composition to Survival of Lactobacillus bulgaricus in Liquid Nitrogen

Concentrated cultures of Lactobacillus bulgaricus were prepared by resuspending cells grown in semisynthetic media in sterile 10% non-fat milk solids. The concentrated cultures were frozen in liquid nitrogen for 24 h. The cell suspensions exhibited decreased viability after storage, and the amount of death varied among the different strains tested. Storage stability of all strains examined was improved by supplementing the growth medium with sodium oleate. Radioisotopes were used to study the fate of sodium oleate with L. bulgaricus NCS1. [1-(14)C]sodium oleate was incorporated solely into the lipid portion of the cells, including both neutral and polar lipids. The fatty acid composition of L. bulgaricus NCS1, NCS2, NCS3, and NCS4 grown with and without sodium oleate was studied. The major fatty acids of strains NCS1, NCS2, and NCS3 grown without sodium oleate were dodecanoic, tetradecanoic, hexadecanoic, hexadecenoic, and octadecenoic acids. In addition to these, strain NCS4 contained C(19) cyclopropane fatty acid. The major fatty acids of all strains grown with sodium oleate were tetradecanoic, hexadecanoic, hexadecenoic, octadecenoic, and C(19) cyclopropane fatty acids. All strains grown in broth containing sodium oleate contained larger amounts of octadecenoic and C(19) cyclopropane fatty acid, and less saturated fatty acids than when grown without sodium oleate. Statistical analyses indicated that C(19) cyclopropane fatty acid was most closely related to stability of the lactobacilli in liquid nitrogen. A negative regression line that was significant at P < 0.001 was obtained when the cellular content of this fatty acid was plotted against death.     

Sh. flexneri population heterogeneity according to the cellular fatty acid makeup]

The composition of fatty acids in the cells of 100 clones of Sh. flexneri, strain 9054, isolated from a dysentery patient was studied by the method of gas chromatography. Fatty acid composition in 75 clones was similar to the fatty acid composition of the initial culture: 25 clones differed to a variable degree from the prevailing group of clones in the content of unsaturated and cyclopropane fatty acids and, to a considerably lesser extent, in the content of palmitic acid and a number of other saturated fatty acids. After the change of the culture medium (agar and broth) the differences in the fatty acid composition of the clones could still be observed. The data obtained in this study indicate the heterogeneity of Shigella population in the composition of cellular fatty acids.     

FAME profiles in Pseudomonas vesicularis during catechol and phenol degradation in the presence of glucose as an additional carbon source.

The aim of this study was to evaluate the impact of catechol and phenol added to culture media separately and with glucose as an additional, easily-degradable carbon source on fatty acid methyl ester (FAME) composition in Pseudomonas vesicularis. Simultaneously, the degradation rates of aromatic substrates used were investigated in single and binary substrate systems. Both catechol and phenol treatments caused changes in the distribution of tested groups of fatty acids. The most noticeable changes included an increase in degree of fatty acid saturation, the appearance of branched and disappearance of hydroxy fatty acids as compared to the control sample with glucose. Under catechol or phenol treatment sat/unsat ratio showed the values of 8.63 and 11.38, respectively, whereas in control cells it reached the value of 2.66. The high level of saturation comes from the high content of cyclopropane fatty acids in bacteria under exposure to aromatic substrates, regardless of the presence of glucose. In these treatments their content was more than 3-fold higher compared to the control. It has been demonstrated that glucose supplementation of culture media containing single aromatic substrate extended the degradation rates of catechol and phenol by P. vesicularis, caused an increase in number of cells but did not significantly change the fatty acid profiles in comparison with bacteria growing on catechol and phenol added to the media individually.     

Replacement of the aliphatic chains of Clostridium acetobutylicum by exogenous fatty acids: regulation of phospholipid and glycolipid composition.

The membrane lipid aliphatic chains of Clostridium acetobutylicum ATCC 4259 have been extensively modified by growth in biotin-free medium containing vitamin-free casein hydrolysate supplemented with either elaidic acid, oleic acid, or mixtures of palmitic and oleic acids. Growth with elaidic acid resulted in polar lipids containing 88.6% 18:1 acyl chains and 94.5% 18:1 ether-linked chains. Growth with oleic acid resulted in comparable levels of enrichment of the lipids with 18:1 chains and C19 chains containing cyclopropane rings. When cells were grown with mixtures of palmitic and oleic acids, the ether-linked chains of the plasmalogens were greater than or equal to 64% 18:1 plus C19 chains containing cyclopropane rings at all ratios of oleic to palmitic acid in the medium. The acyl chains reflected the palmitic acid content of the medium more closely. Marked changes were observed in both phospholipid and glycosyldiglyceride compositions as the lipid acyl and ether-linked chains became more enriched with unsaturated and cyclopropane chains. The ratio of the glycerol acetal of plasmenylethanolamine to phosphatidylethanolamine increased, the ratio of cardiolipin to phosphatidylglycerol decreased, and the ratio of diglycosyldiglyceride to monoglycosyldiglyceride increased. However, the monoglycosyldiglyceride/diglycosyldiglyceride ratio was lower for cells grown on 100% oleic acid than for cells grown on 60 or 80% oleic acid. In the membranes of cells grown on 100% oleic acid, the ratio of glycolipids to phospholipids was lower than that found in cells grown on 60% oleic acid. These results indicate that C. acetobutylicum regulates its polar lipid composition in a complex manner involving phospholipids and glycosyldiglycerides. These changes can affect the equilibria between those lipids that form bilayers and those lipids that tend to form nonlamellar phases when enriched with unsaturated aliphatic chains. Phosphoglycolipids of unknown structure were also observed in cells grown either with biotin or with fatty acids. The content of the most abundant phosphoglycolipid also varied with the degree of unsaturation of the cellular lipids.     

S-Adenosylmethionine,cyclopropane fatty acid synthase,and the production of lactobacillic acid in Lactobacillus plantarum

S-Adenosylmethionine (AdoMet) levels in Lactobacillus plantarum were found to increase concomitantly with the production of membrane cyclopropane fatty acids under normal growth conditions. This increase in AdoMet did not occur when the pH of the culture medium (initially pH 6.5) was not allowed to fall (pH 4 or lower) during growth. When the culture medium was maintained at pH 6.5, cyclopropane fatty acid synthesis also remained low. While the activity of cyclopropane fatty acid synthase is increased as the pH decreases, the activity of AdoMet synthetase is largely unaffected by the variation of pH of the culture medium. The production of cyclopropane fatty acids is also dependent upon continued protein synthesis; in the presence of chloramphenicol cyclopropane fatty acid synthase activity is decreased, resulting in a lowered production of cyclopropane fatty acids. A dramatic increase in AdoMet levels occurs in the presence of chloramphenicol. It is proposed that AdoMet levels, in conjunction with cyclopropane fatty acid synthase activities, regulate cyclopropane fatty acid synthesis in L. plantarum.     

The fatty acid composition of Haemophilus and Pasteurella multocida cells as a phylogenetic marker

When grown on meat-peptone agar with heated blood, different Haemophilus species (H. influenzae, H. parahaemolyticus, H. parasuis, H. pleuropneumoniae), including different H. influenzae serovars (a, b, c, d, e, f), and Pasteurella multocida have identical fatty acid composition, characterized by the prevalence of fatty acids with 16 carbon atoms, constituting about 70% and more of the total number of fatty acids, and a low level of fatty acids with 18 carbon atoms. P. multocida strains cultivated on meat-peptone agar with unheated blood have a greatly increased content of fatty acids with 18 carbon atoms, while the content of fatty acids with 16 carbon atoms is much lower. The identity of fatty acid composition under similar cultivation conditions, together with their similarity in other phenetic signs, is indicative of close phylogenic relationship between bacteria belonging to the genus Haemophilus and P. multocida.     

Fatty acid makeup of various Brucella species and its relationship to the culture medium]

Gas chromatographic method was applied to the study of the fatty acid composition (in Br. melitensis, Br. abortus, Br. suis, and Br. ovis strains. Fatty acid composition was similar in the mentioned brucellae species, except Br. suis No. 1330 significantly differing by this sign. Methyleneoctadecanoic acid content was considerably elevated, and that of octadecenoic -- reduced in brucellae grown on liver agar with the addition of serum and on meat-peptone agar in comparison with brucellae grown on liver agar; apparently this represents one of the mechanisms of the microorganism adaptation to the less favourable conditions of the nutrient medium. Passage of Br. ovis strain through the guinea pig organism led to the appearance of brucellae forming two types of colonies when grown on liver agar with the addition of serum. The fatty acid composition of brucellae forming small transparent colonies was the same as that of the initial culture with the prevalence of methyleneoctadecanoic acid; as to brucellae with larger colonies with irregular margin and nontransparent centre of the colony--octadecenoic acid prevailed in their fatty acid composition, i.e. their composition was similar to such in brucellae of the melitensis and abortus species grown on liver agar.     

Evidence for the Existence of an Aerobic Pathway for Synthesis of Monounsaturated Fatty Acids by Alcaligenes faecalis

Studies on the composition of total fatty acids of Alcaligenes faecalis harvested at different growth phases have been carried out. Ability of the organism to desaturate palmitic and stearic acid has also been tested. The organism contained palmitic (16:0), stearic (18:0), palmitoleic (16:1), cis-vaccenic (18:1), cyclopropane (17: big dn tri, open and 19: big dn tri, open), and three hydroxy acids. Increase in cyclopropane acids and corresponding decrease in monounsaturated acids in direct proportion to the age of the culture were observed, whereas other fatty acids remained relatively unaltered. A growing culture of the organism was found to desaturate [1-(14)C]palmitic acid supplied in the medium to hexadecanoic acid. Resting cells desaturated [1-(14)C]palmitic and [1-(14)C]stearic acid giving rise to about 50% of (14)C in the COOH group of corresponding monounsaturated fatty acids.     

Fatty acid composition of lipopolysaccharides of the strains of different species of Yersinia

The fatty acid composition of lipopolysaccharides of the strains of Y. enterocolitica, Y. intermedia, Y. frederiksenii and Y. ruckeri studied during cultivation on meat-peptone agar is characterized by the predominance of 3-hydroxytetradecanoic and dodecanoic acids. Closely related to the mentioned bacteria is the strain of Y. kristensenii which is distinguished only by its higher level of hexadecanoic acid. The strains of Y. pseudotuberculosis and the vaccine strain of Y. pestis have a uniform fatty acid composition of lipopolysaccharides with predominance of 3-hydroxytetradecanoic acid. Their relatively low level of dodecanoic acid conditions the characteristic fatty acid spectrum of lipopolysaccharides which differs from that of the above mentioned group of Yersinia. The peculiarities of the fatty acid composition of lipopolysaccharides of both groups of Yersinia are preserved during growth on meat-peptone broth, but the increase in the level of hexadecanoic acid balances the differences between Y. kristensenii, the other Y. enterocolitica-like bacteria and Y. ruckeri. The obtained results confirm close relationship of Y. pseudotuberculosis and Y. pestis, and also of Y. enterocolitica and Y. enterocolitica-like bacteria, showing propinquity of Y. ruckeri to the latter.     

Effect of salinity of medium on cellular fatty acid composition of marine algaPorphyridium cruentum (Rhodophyceae)

Porphyridium cruentum Näg. (clone 161) was found to grow best in medium containing between 0.45 M and 0.8 M NaCl. From studies done on growing cultures, the palmitic acid content of the cells decreased with increasing NaCl concentration of the medium. Conversely, when the culture was transferred from a 0.8 M NaCl medium to 0.2 M NaCl, the amount of palmitic acid in thePorphyridium cells increased with time of incubation and it contributed up to 64.5% of the total fatty acid content. There appears to be a negative correlation between the cellular content of palmitic acid and the growth lag. The oleic acid content varied only marginally with increasing NaCl concentration. The poly-unsaturated acid content (linolenic and arachidonic acids) decreased initially and then increased with NaCl concentration up to and beyond ca. 0.8 M NaCl respectively. At 1.5 M NaCl, the poly-unsaturated fatty acids amounted to 78.2% of the total fatty acids in the cell. For stationary phaseP. cruentum cultures, a similar relationship existed between fatty acids and NaCl concentration. However, palmitic acid was accumulated up to three-fold more when compared to the exponential culture grown in low salinity. In addition stearic acid was also found in significant quantities.     

Cellular fatty acid patterns inPseudomonas sp. CF600 during catechol and phenol degradation in media supplemented with glucose as an additional carbon source

Fatty acid composition inPseudomonas sp. CF600 during degradation of catechol and phenol individually and their mixture was investigated. Moreover, the influence of glucose as an additional, easily degradable carbon source on fatty acid profiling in bacteria grown on these aromatic substrates was studied. Both catechol and phenol treatments caused in bacterial cells crucial changes in the distribution of tested groups of fatty acids. The major changes included the increase of fatty acid saturation, decrease in the percentage of cyclopropane fatty acid 17:0cy and the appearance of branched and hydroxy fatty acids. Under catechol, phenol and their mixture exposure saturated/unsaturated ratio showed the value 6.5, 5.68 and 6.38 whereas in control cells this ratio reached the value 3.05. As a response to aromatic compounds bacteria formed fatty acids that were not detected in control cells growing on glucose. It has been demonstrated that the supplementation of cultured media containing single aromatic substrates or/and their mixture with glucose resulted in changes in degradation rates of catechol and phenol. It seemed that glucose influenced some metabolic pathways responsible for the assimilation of aromatic compounds. The incubation of cells in the presence of aromatic compounds and glucose rapidly led to alterations of whole-cell derived fatty acid composition. The most important changes were associated with saturation level of fatty acids and cyclopropane fatty acid contents.     

Effect of culture conditions on lipid and gamma-linolenic acid production by mucoraceous fungi

The effect of various culture conditions on growth, lipid production and fatty acid composition in Mucor rouxii and Mucor sp.1b were studied. Total lipid production was higher in media containing potassium nitrate for both the cultures (30%) and cultures grown on plant seed oil produced more than 44% lipid. Among the carbon sources tested, γ-linolenic acid (GLA) production was maximal in cultures grown on glucose. The major fatty acids produced by these two cultures were palmitic, stearic and oleic acids. Levels of GLA in M. rouxii and M. sp.1b was in the range of 3–17% under different culture conditions. Lactose was a poor promoter for biomass and lipid production in both cultures. No GLA was found in fungal cultures grown on sesame oil. The optimal conditions for the production of GLA was standardised in these cultures.     

Some factors affecting cyclopropane acid formation in Escherichia coli

1. The fatty acid composition of the extractable lipids of Escherichia coli varied with growth conditions. 2. The principal fatty acids were palmitic acid, hexadecenoic acid, octadecenoic acid and the cyclopropane acids, methylenehexadecanoic acid and methyleneoctadecanoic acid. 3. Cyclopropane acid formation from monoenoic acids was increased by acid media, poor oxygen supply, or high growth temperature. 4. Cyclopropane acid formation was decreased by alkaline media, well oxygenated conditions, the presence of citrate, or lack of Mg(2+).     

Alterations in the composition and bacteriophage-binding properties of walls of Staphylococcus aureus H grown in continuous culture in simplified defined media.

A nutritional mutant of Staphylococcus aureus H has been isolated and grown in media in which the only amino acids are arginine, cysteine, glutamic acid and proline. Walls of the bacteria grown in such media in continuous culture under potassium limitation differ in composition from walls of the bacteria grown in batch culture in rich nutrient broth in that they contain less glycine, the peptidoglycan component is less highly cross-linked and the teichoic acid component contains a reduced proportion of N-acetylglucosaminyl substituents. Walls of the potassium-limited bacteria retain the ability to bind bacteriophage 52a but are more susceptible to the action of lytic peptidases than are wall samples in which the peptidoglycan is more highly cross-linked. Teichoic acid was present in walls of the bacteria grown under phosphate limitation in the defined medium and these walls were also able to absorb bacteriophage 52a.     

Long-chain fatty acid perturbations in Mycoplasma pneumoniae

The fatty acid content of Mycoplasma pneumoniae increased 2.5- to 9.6-fold when the growth medium was supplemented with a saturated, unsaturated, or beta-hydroxy fatty acid, the greatest increase occurring with palmitic acid. The amount of each supplemented fatty acid found within this organism was 2.8 to 5.5% of the total fatty acid content; the exception was palmitic acid. Up to 57% of the palmitic acid was utilized from the supplemented medium, whereas only 0.2 to 10% of the other fatty acids was utilized. Chromatographic and isotopic analyses revealed that 22% of the labeled palmitic acid incorporated from the palmitic acid-supplemented medium remained free in this organism. Also, even though complex lipid synthesis increased a minimum of 3.8-fold under these conditions, this mycoplasma continued to incorporate intact complex lipids from the growth medium. Bacteriostatic and bactericidal studies which used high concentrations of various long-chain fatty acids showed that only palmitic, myristic, and beta-hydroxydecanoic acids were not bactericidal. The addition of palmitic acid to the growth medium resulted in the formation of exceedingly long, filamentous cells in approximately 25% of the population. Osmotic fragility and electron spin resonance spectroscopy studies showed a correlation among this increased fatty acid content, decreased membrane fluidity, and the increased osmotic fragility of palmitic acid-grown cells. In addition, these cells had a lowered cholesterol content. The effect of such compositional changes on osmotic fragility is discussed in this paper. Finally, the profound increase in the total fatty acid content of palmitic acid-grown cells altered neither sensitivity to tetracycline or erythromycin nor the amount of hydrogen peroxide secreted.     

Formation of organic acids by the fungus Cladosporium resinae in media containing n-alkanes]

The so-called fungus Cladosporium resinae that often occurs in oil fuels ane increases their acidity grows well at the expense of n-alkanes from C11 to C16. On the n-alkane containing media the fungus grows slowly and only under the stationary conditions. During the fungal cultivation on the media containing n-dodecane or kerosene the culture liquid shows acetic acid and other fatty acids, ketoacids (pyruvic and alpha-ketoglutaric) as well as citric and isocitric acids that dominate among nonvolatile acids. Upon nitrogen deficiency in the medium and comparatively good aeration the content of citric acids increases. The culture liquid of the fungus devoid from the mycelium and nonutilized n-alkanes can be used a a nutrient medium for different microorganisms.     

Effects of Culture Method and Growth Phase on Free Lipid Composition of Yersinia pseudotuberculosis

The influence of culture method (free-floating cells in liquid nutrient broth or bacteria attached to agar surface on solid agarized medium of the same formulation) and bacterial age on the composition of free lipids in Yersinia pseudotuber-culosis (O:Ib serovar, strain KS 3058) grown in the cold (5°C) has been investigated. The specific growth rate of the bacteria on solid medium was about threefold less than that in liquid medium. The qualitative composition of phospholipids and fatty acids only slightly depended on the bacterial culture method. At the same time, the colonially growing cultures contained somewhat more total lipids, they synthesized more phospholipids, in the linear growth phase they contained more lysophosphatides, and they had higher fatty acid unsaturation index and higher pathogenic potential than their planktonic counterparts grown in otherwise identical conditions. The bacterial growth phase influenced the amount of 3-hydroxytetrade-canoic acid and, indirectly, that of lipopolysaccharide. The dynamics of changes in the amount of this acid with bacterial age was opposite in the surface and broth cultures.