Gluconobacter Cerinus Research Articles

Antimicrobial activity of the ornithine-containing lipid isolated from Gluconobacter cerinus.

Antimicrobial activity of the ornithine-containing lipid isolated from Gluconobacter cerinus.

An ornithine-containing lipid isolated from Gluconobacter cerinus

The three ornithine-containing lipids of Gluconobacter cerinus were isolated from each other. One of the three lipids was postulated as N α -3-hydroxypalmitoylornithine, to the fatty acid moiety of which 2-hydroxy fatty acid is linked by an ester linkage. The 2-hydroxy acid was possibly cis-11,12-methylene-2-hydroxyoctadecanoate. Such an ornithine-containing lipid was found to be distributed in other acetic acid bacteria.

Phospholipid composition of Gluconobacter cerinus.

Phospholipids of Gluconobacter cerinus were investigated. The cells of this bacterium were found to have cardiolipin, phosphatidylglycerol, phosphatidylethanolamine and phosphatidylcholine together with three ornithine-containing lipids. Phosphatidylcholine was the most abundant of these phospholipids, and calculated at 31.0% of total phospholipids in the cells at the late logarithmic phase. The fatty acid of this lipid was composed of palmitate, stearate and vaccenate, and there were no remarkable differences in quality among fatty acids of these four phospholipids. The phosphatidylcholine was also found in other acetic acid bacteria.

Occurrence of phosphatidylcholine in Gluconobacter cerinus.

(1975). Occurrence of Phosphatidylcholine in Gluconobacter cerinus. Agricultural and Biological Chemistry: Vol. 39, No. 11, pp. 2261-2262.

Metabolic consequences of a block in the synthesis of 5-keto-D-fructose in a mutant of Gluconobacter cerinus.

A mutant of Gluconobacter cerinus var. ammoniacus, IFO 3267, has been isolated which is deficient with respect to fructose 5-dehydrogenase, the enzyme catalyzing the oxidation of d-fructose to 5-keto-d-fructose (5 KF). Growth of this mutant on fructose as the sole carbon source was impaired unless the culture medium was supplemented with 5 KF. Significant randomization of the 1 and 6 positions of fructose has been reported previously for the wild-type organism during growth on this ketohexose. The pattern of (3)H incorporation into the C5 position of ribonucleic acid-ribose when the mutant was grown on [1-(3)H]fructose and [6-(3)H]fructose in the presence of 5 KF indicated that such randomization did not occur in this variant. The randomization observed in the wild type is, therefore, a consequence of the partial oxidation of fructose to the symmetrical 5 KF intermediate prior to its conversion to pentose. When the mutant was grown on [1-(3)H]fructose in the presence of unlabeled 5 KF, [5-(3)H]fructose appeared in the culture medium. Thus, 5 KF served as the oxidant for the nicotinamide adenine dinucleotide phosphate, reduced form, generated during growth on fructose.

5-Keto-D-fructose: formation and utilization in the course of D-fructose as similation by Gluconabacter cerinus.

The accumulation of 5-keto-d-fructose (5KF) by Gluconobacter cerinus grown on d-fructose in unbuffered medium was shown to be optimal at pH 4.0 after cell growth ceased. During the exponential phase of growth or at neutral pH after the onset of the stationary phase, 5KF production continued but did not accumulate because of its rapid reutilization by reduction to d-fructose. The extent of isotope incorporation into C5 of ribonucleic acid ribose when cells were grown in the presence of specifically labeled d-glucose and d-fructose clearly indicated that (i) the hexose monophosphate oxidative pathway is the predominant metabolic route for carbohydrate assimilation and (ii) extensive randomization of label between C1 and C6 of d-fructose occurred prior to its conversion into pentose. It is suggested that the cyclic oxidation and reduction through the symmetrical 5KF molecule, which accounts for the observed randomization of isotope in d-fructose, provides the cells with an effective mechanism for the regeneration of nicotinamide adenine dinucleotide phosphate during the period of intensive growth.

Purification and Properties of a Nicotinamide Adenine Dinucleotide Phosphate-linked Aldohexose Dehydrogenase from Gluconobacter cerinus

Abstract A soluble NADP-linked aldohexose dehydrogenase has been isolated and purified about 100-fold from extracts of Gluconobacter cerinus cells. The enzyme catalyzes the oxidation of d-glucose, d-mannose, 2-deoxy-d-glucose, and 2-amino-2-deoxy-d-mannose with apparent Km values at pH 8.0 of 5.3 x 10-3 m, 1.8 x 10-3 m, 3.9 x 10-2 m, and 2.9 x 10-2 m, respectively. Other aldohexoses or aldopentoses examined were inert either as substrates or as inhibitors. The product of the enzymatic oxidation of d-glucose was characterized as the corresponding hexonic acid-δ-lactone. Reversibility of the reaction has been shown by the identification of d-glucose as the product of NADPH oxidation in the presence of d-glucono-δ-lactone. The enzyme shows high specificity for NADP+ (Km = 1.2 x 10-5 m) and NADPH (Ki = 3.8 x 10-5 m).

5-Keto-D-fructose: V. PHOSPHORYLATION BY YEAST HEXOKINASE

Abstract Yeast hexokinase was shown to catalyze the phosphorylation of 5-keto-d-fructose (d-threo-2,5-hexodiulose) in the presence of ATP. The product was identified as a monophosphate ester. A procedure for the preparation of this ester and some of its properties are described. Reduction of the monophosphate ester by the NADPH-5-keto-d-fructose reductase from Gluconobacter cerinus yielded fructose 1-phosphate.

Coenzyme Q10 in the Respiratory Chain Linked to Fructose Dehydrogenase of Gluconobacter cerinus

Coenzyme Q10 in the Respiratory Chain Linked to Fructose Dehydrogenase of Gluconobacter cerinus

5-Keto-d-fructose: IV. A SPECIFIC REDUCED NICOTINAMIDE ADENINE DINUCLEOTIDE PHOSPHATE-LINKED REDUCTASE FROM GLUCONOBACTER CERINUS

Abstract A specific reduced nicotinamide adenine dinucleotide phosphate-linked 5-keto-d-fructose reductase has been isolated and purified approximately 1200-fold from extracts of Gluconobacter cerinus. The reaction catalyzed was found to be 5-Keto-d-fructose + NADPH + H+ ⇌ d-fructose + NADP+ with an equilibrium far towards the right (Keq = 2 x 1010). Km values for NADPH, NADP+, 5-ketofructose, and fructose were 1.8 x 10-6 m; 1.3 x 10-3 m; 4.5 x 10-3 m; and 7.0 x 10-2 m, respectively, at pH 7.4.