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Chemical studies of the glucose metabolism of Pseudomonas aeruginosa A.T.C. 9027 Idler, David Richard

Abstract

The first part of this work was undertaken in an effort to devise a satisfactory fractionation procedure for studying the phosphorylated intermediates in the glucose metabolism of P. Aeruginosa. By chemical and chromatographic analysis of these fractions it was hoped to obtain more information on the chemical sequence of the breakdown. A modified barium fractionation procedure is presented for isolating the trichloroacetic acid soluble phosphate esters from the cells of P. Aeruginosa. Several conclusions are drawn from the analysis of the barium fractions. The adenosine phosphate coenzyme system is shown to be present. Phosphoglyceric acid and hexose-di-phosphate are absent. Evidence is presented to show that glucose-6-phosphate is probably not present and neither phosphopyruvic acid nor the triose phosphates occur in detectable concentrations. These data all point to a phosphorylation mechanism which does not involve an Embden-Meyerhof system. Other than the coenzyme systems there are no nitrogenous compounds present. All fractions contain phosphate esters which have reducing values before hydrolysis. The reducing values, on hydrolysis with normal hydrochloric acid, parallel the release of inorganic phosphate. Every barium fraction contains a large percentage of non-phosphorylated compounds. These compounds are not reducing to the Folin-Malmros reagent. In the chromatography studies several solvents have been found satisfactory for the resolution of sugars, particularly pentoses. The presence of an arabinose phosphate is established by paper chromatography. Arabonic acid is also identified but the chromatographic evidence is not considered conclusive. The importance of these two compounds is discussed in the light of the present knowledge of glucose breakdown by P. Aeruginosa. A new developer is presented for use in the chromatography of certain phosphate esters. The second part of this work was undertaken in an effort to establish the chemical composition of the water and acid insoluble gum produced when P. Aeruginosa is grown on a glucose-mineral salts media. The amino acids present in the gum are alanine, glutamic acid and serine. These were identified by paper chromatography. Amino acid carbon dioxide accounts for 9.25% of the dry gum weight. The uronic acid content of the gum is 31.4%. The phosphorus content (as PO₄) is 13.2%. Fructose is present. The gum is very resistant to hydrolysis by four normal hydrochloric acid. Ten hours are required to liberate all carbon dioxide from the uronic acid component. The iodine reaction is negative. No sugars could be identified by paper chromatography.

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