Chemical composition of Desulfovibrio desulfuricans lipid A

Lipopolysaccharides also called endotoxins are an integral component of the outer membrane of Gram-negative bacteria. When released from the bacterial surface, they interact with a host immune system, triggering excessive inflammatory response. Lipid A is the biologically most active part of endotoxin, and its activity is modulated by the quantity, quality and arrangement of its fatty acids. Desulfovibrio desulfuricans is sulfate-reducing, Gram-negative bacterium that is supposed to be opportunistic pathogens of humans and animals. In the present study, chemical composition of lipid A from various strains of D. desulfuricans was analyzed by gas chromatography/mass spectrometry. It was found that the fatty acid component of the lipid A contains dodecanoic, tetradecanoic, 3-hydroxytetradecanoic and hexadecanoic acids, and its carbohydrate core is composed of glucosamine. The analysis of 3-acyloxyacyl residue of the lipid A revealed the presence of amide-bound 3-(dodecanoyloxy)tetradecanoic and 3-(hexadecanoyloxy)tetradecanoic acids and ester-bound 3-(tetradecanoyloxy)tetradecanoic acid. It was concluded that both fatty acid and 3-acyloxyacyl residue profiles of the lipid A from the studied bacteria were similar to those of E. coli and S.enterica

Biomonitoring of surface water by synchronous culture of Chlorella vulgaris algae

A possible use of synchronous culture of Chlorella vulgaris algae has been examined as a shortterm bioassay for water quality control. Experiments were performed with algae cultivated in liquid media prepared with distilled water (control) and with water aliquots sampled from the Goczałkowice Reservoir. It has been demonstrated that changes in the absorbance (at 680 nm) of algae liquid synchronous culture and the rate of algae cellular division may be useful as criteria for water quality control. Changes in the algae metabolic activity are clearly a sign of the July flood and autumnal water quality changes

METOPROLOL EFFECT ON FATTY ACIDS COMPOSITION OF CELL MEMBRANE PHOSPHOLIPIDS

It is quite well known that β-blockers influence the stability of cell membranes, but the effect of metoprolol on the composition of cell membrane lipids is not established. On the other hand, synchronous culture of Chlorella vulgaris cells, which consists of cells brought to the same developmental stage by cycling lighting, provides a convenient biological model in unidirectional analyses aimed at assessment of effects of xenobiotics on cells. Advantages of the model include short life cycle and possibility to control metabolic processes of the cells across the broad range. We assessed the effect of metoprolol on fatty acids composition of cell membrane phospholipids in consecutive life cycle stages of Chlorella vulgaris. Lipids were extracted using a chlorofonn/methanol method. Phospholipids were precipitated from the chloroform phase with cold acetone and following centrifugation the pellet of phospholipids was hydrolyzed in alkaline solution. Fatty acids were extracted with petroleum ether and then methylated with BF3-methanol. This protocol produced methyl esters of fatty acids which were subjected to GC-MS analysis. Metoprolol had no effect on the number of progeny cells of Chlorella vulgaris throughout their life cycle at the concentration range tested (5x10-5 M, 5x10-6 M, 5x10-7 M). However, we observed stimulation of biological activity of Chlorclla cells as measured by spectrophotomctry at λ=680 nm. Metoprolol, at the highest concentration, increased phospholipids content in mother cells. Simultaneously, relative amount and saturation level of thc fatty acids remained constant

Comparison of lipopolysaccharides composition of two different strains of Helicobacter pylori

Abstract Background Helicobacter pylori (H. pylori) is a Gram-negative, microaerophilic bacterium that is recognized as a major cause of chronic gastritis, peptic ulcers, and gastric cancer. Comparable to other Gram-negative bacteria, lipopolysaccharides (LPS) are an important cellular component of the outer membrane of H. pylori. The LPS of this organism plays a key role in its colonization and persistence in the stomach. In addition, H. pylori LPS modulates pathogen-induced host inflammatory responses resulting in chronic inflammation within the gastrointestinal tract. Very little is known about the comparative LPS compositions of different strains of H. pylori with varied degree of virulence in human. Therefore, LPS was analyzed from two strains of H. pylori with differing potency in inducing inflammatory responses (SS1 and G27). LPS were extracted from aqueous and phenol layer of hot-phenol water extraction method and subjected for composition analysis by gas chromatography – mass spectrometry (GC-MS) to sugar and fatty acid compositions. Results The major difference between the two strains of H. pylori is the presence of Rhamnose, Fucose and GalNAc in the SS1 strain, which was either not found or with low abundance in the G27 strain. On the other hand, high amount of Mannose was present in G27 in comparison to SS1. Fatty acid composition of lipid-A portion also showed considerable amount of differences between the two strains, phenol layer of SS1 had enhanced amount of 3 hydroxy decanoic acid (3-OH-C10:0) and 3-hydroxy dodecanoic acid (3-OH-C12:0) which were not present in G27, whereas myristic acid (C14:0) was present in G27 in relatively high amount. Conclusion The composition analysis of H. pylori LPS, revealed differences in sugars and fatty acids composition between a mouse adapted strain SS1 and G27. This knowledge provides a novel way to dissect out their importance in host-pathogen interaction in further studies