The carotenoid pigments of a marine Bacillus firmus strain.

As carotenoids have important biological functions, it is important to discover new natural sources of these pigments. The bacterial strains isolated from a sea water rock pool were cultivated on marine agar containing yeast extract and identified by conventional methods. The bacterial pigments were extracted with methanol and analyzed by reversed-phase HPLC with diode array detection. The major pigment of a Bacillus firmus strain was identified as astaxanthin; the results obtained suggest potential use of this bacterium in aquaculture and in pharmaceutical field.

Heparin surface treatment of poly(methylmethacrylate) alters adhesion of a Staphylococcus aureus strain: utility of bacterial fatty acid analysis.

Bacterial adhesion on biomaterials is an important cause of associated infection. Many authors have studied the adhesion mechanisms of bacteria on biomaterials. These studies were useful in making materials more and more refractory to bacterial adhesion. We analysed the gas chromatographic modifications of structural fatty acids of a Staphylococcus aureus strain after adhesion on two polymers, poly(methylmethacrylate) (PMMA), whose biological compatibility is known, and heparin-surface-modified PMMA (HSM-PMMA). We noted changes to the chromatographic peaks peculiar to the fatty acids of S. aureus for each tested material and particularly for HSM-PMMA.

High performance liquid chromatographic strategy for the analysis of exopolysaccharides extracted from pathogenic bacteria.

A high performance liquid chromatographic (HPLC) method has been developed to permit the rapid comparison of acidic polysaccharides of diverse compositions and the sensitive determination of their constituents. It is based on two combined analyses of the polysaccharide hydrolysates--a separation of the released compounds by ion-moderated partition chromatography with UV detection at two wavelengths and a separation of the sugar dansylhydrazine derivatives by reversed phase chromatography. The former permits identification and quantitation of uronic and carboxylic acids, the latter permits more sensitive and specific determination of the neutral aldoses. Some bacterial exopolysaccharides have been used to demonstrate the validity of this HPLC procedure for the chemical characterization of uronic acid-containing polysaccharides. This method appears to be useful for studying capsular polysaccharides, which are involved in the evasion of phagocytosis by pathogenic bacteria.

Applications of high-performance liquid chromatography in bacteriology. I. Determination of metabolites.

The chemotaxonomic approach to the identification of pathogenic bacteria for clinical purposes is surveyed. Primary interest is focused on the applications of HPLC to the determination of metabolic products from anaerobic bacteria. The use of HPLC is attractive as different classes of short-chain acids can be determined in a single analysis. Chromatographic conditions are extensively described, emphasizing the effects of changing variables on the HPLC profiles of analytes. The application of labelling procedures to bacterial metabolites can markedly increase the sensitivity of the analysis of pathological fluids. HPLC appears to be potentially useful in clinical bacteriology for the diagnosis of anaerobic infections.

Suppression of tricarboxylic acid cycle in Escherichia coli exposed to sub-MICs of aminoglycosides.

The metabolic activity of Escherichia coli ATCC 25922 challenged with sub-MICs of aminoglycosides was analyzed with a batch calorimeter. High-performance and gas-liquid chromatographic techniques were utilized to evaluate the concentrations of metabolic reactants, intermediates, and end products. The data reported indicate that aminoglycosides inhibit or delay bacterial catabolism of carboxylic acids, with the following relative degrees of activity: amikacin greater than gentamicin greater than sisomicin greater than netilmicin greater than kanamycin. The decrease in total biomass production was proportional to the degree of tricarboxylic acid cycle inhibition.

Rapid identification of Bacteroides species by high-performance liquid chromatography.

High-performance liquid chromatography was evaluated for the rapid identification of Bacteroides species of clinical interest. Each isolate was inoculated into a defined chemical medium containing primarily carbohydrates and was incubated aerobically at 37 degrees C for 1 h. After centrifugation, the supernatants were placed on ice to stop further enzymatic reactions. Specimens were injected into an Aminex HPX-87H column in order to determine carbohydrates and acid metabolic products. Peak areas of carbohydrates for each isolate were compared with those for uninoculated medium. As the utilization indexes of raffinose, lactose and arabinose were found to be particularly significant, the patterns of carbohydrate utilization could be used for the identification of Bacteroides species. This method can be adapted for diagnostic laboratory use and has good potential for automated microbial identification.

Human erythrocyte glucose 6-phosphate dehydrogenase. Influence of coenzyme derivatives on thermostability and kinetic properties.

A number of derivatives of NADP(H) were tested with respect to their effectiveness in interacting with tetrameric glucose 6-phosphate dehydrogenase (G6PD) retaining only the fraction of "structural" coenzyme (4 moles NADP). Interaction was probed by two parameters: a) increased thermostability of G6PD activity, measured as the difference in the corresponding transition temperature (Tm) of samples containing and lacking the NADP derivatives, respectively; b) competitive inhibition toward NADP, expressed a Ki values. Protection afforded by the various effectors against thermal denaturation decreased in the following order: NADPH, NADP, PADP-ribose, adenosine 2',5'-P2. Other NADP derivatives, including 2',3' cyclic NADP, NMN, NMNH, nicotinamide, adenosine 2'-P, were uneffective in respect to this property. The kinetically measured affinity was the greatest for NADPH and decreased progressively for the following effectors: PADP-ribose, NADP, NMNH, PADP-glycolaldehyde, adenosine 2',5'-P2, PADP-ribitol, adenosine 2'-P. Nicotinamide and NMN were uneffective on NADP binding. These data show that the adenosine moiety of NADP is more critically involved than the nicotinamide portion in the interaction with human G6PD.