摘要:

Cell-free extracts ofPseudomonas fluorescens, strain OSU 64, derived by means of sonic oscillation and alumina grinding, were assayed to determine the localization of enzymes necessary for the oxidation of glucose, gluconate, and glucose-6-phosphate. Glucose and gluconate were oxidized to 2-ketogluconate by both the supernatant and particulate fractions of the extracts. Approximately 40% of the activity for the oxidation of glucose was demonstrated to be in the supernatant fraction and 60% in the particulate fraction. Activity for the oxidation of gluconate was found to be located with approximately 50% in each fraction. Oxidation of glucose-6-phosphate was observed only in the soluble portion.

ISSN:0008-4166    

DOI:10.1139/m58-001

出版商:NRC Research Press    

年代:1958

数据来源: NRC

摘要:

Examination by filter paper partition chromatography and filter paper iono-phoresis of the cobalamins present in cultures ofPropionibacterium arabinosumgrown in a medium containing glucose, yeast extract, and salts showed that only adenine-hydroxo-cobalamin was present. Addition of 5 6-dimethylbenzimidazole to the growing cultures resulted in formation of a cobalamin containing this substance in the nucleotide portion of the molecule. Cobalamins containing benzimidazole, 5-methylbenzimidazole, 2,6-diaminopurine, benzotriazole, benzothiazole, and 5-nitrobenzimidazole in the nucleotide were prepared by this procedure and found to have the migration and biological characteristics of these cobalamins as previously described in the literature. New cobalamins have also been prepared presumably including those containing 5-trifluoromethylbenzimidazole, phenazine, 2-hydroxyphenazine, 4-bromo-6-methoxybenzimidazole, 3,4-dihydro-4-oxoquinazoline, 4-chloro-8-nitroquinazoline, and quinoxaline in the nucleotide. All of these new cobalamins were found to stimulate the growth of cobalamin-requiring cultures ofEscherichia coli,Lactobacillus leichmannii, andOchromonas malhamensis.

ISSN:0008-4166    

DOI:10.1139/m58-002

出版商:NRC Research Press    

年代:1958

数据来源: NRC

摘要:

Thirty-one bacterial species showed a yellow primary fluorescence (auto-fluorescence) which could be observed visually with a commercial fluorescence microscope and recorded on photographic emulsions.The present work emphasizes the importance of this natural property for the study of bacteria, either for taxonomic purposes or as a preliminary step when using fluorochromes. The lack of an easy and reliable technique for detecting the existence of primary fluorescence in bacteria is probably the reason why very little work has been done in this field. Nothing is quoted about this property of bacteria in most textbooks of bacteriology.We deliberately left over the apparently related subject of the well-known macroscopic fluorescence of somePseudomonas,Azotomonas, andAzotobactercultures which is associated with diffusible pigments equally present inside and outside the bacteria. The aim of our study was the detection of the primary fluorescence of the bacterial cell itself.In order to examine and photograph the primary fluorescence of bacteria with greater accuracy, two important improvements in technique were introduced (a) elimination of fluorescent particles, present in all the culture media which we used, by the simple expedient of growing the bacteria on cellophane, (b) increased reliability of black and white microphotographs through the use of the bright-field condenser. By using the old and usual method of fluorescence microscopy with the dark-field condenser and ultraviolet rays, it is not always possible to determine on black and white photomicrographs whether or not a given bacterium is fluorescent. With the latter setup the images can be produced not only by the visible light emitted by the fluorescent bacteria but also by the unfiltered rays which eventually pass through the system of filters during long exposures. To overcome this difficulty, we now use the bright-field condenser with ultraviolet or blue rays and the appropriate selective filters. The specimens are best prepared as dry smears, covered with an Euphos selective filter (cover glass) using no immersion liquid. This combination is more likely to give reliable information on the presence or absence of fluorescence.

ISSN:0008-4166    

DOI:10.1139/m58-003

出版商:NRC Research Press    

年代:1958

数据来源: NRC

摘要:

Cell-free preparations ofAcetobacter melanogenumreadily oxidized glucose-6-phosphate, glucose-1-phosphate, fructose-6-phosphate, 6-phosphogluconate, and ribose-5-phosphate; fructose-1,6-diphosphate was utilized very slowly. The presence of an active triphosphopyridine nucleotide (TPN)-linked glucose-6-phosphate dehydrogenase and of phosphohexose isomerase was demonstrated; phosphoglucomutase was also present in these extracts. 6-Phosphogluconate dehydrogenase activity (TPN-linked) was low in extracts of glucose-grown cells, but was high in sonates of gluconate-grown cells. An active oxidizing system for reduced diphosphopyridine nucleotide was present but transhydrogenase was not detected. Pyruvate was produced extensively from 6-phosphogluconate but only slowly from ribose-5-phosphate; fluoride inhibited pyruvate formation from both substances. Ribose-5-phosphate was degraded readily via the transketolase-transaldolase series of reactions. Glyceraldehyde-3-phosphate dehydrogenase, hexokinase, gluconokinase, 2-ketogluconokinase, and aldolase were detected but not phosphohexokinase. The results suggest that glucose is oxidized either directly or after phosphorylation but is not metabolized glycolytically. The oxidation of hexose phosphate appears to occur predominantly as a result of the splitting of 6-phosphogluconate to pyruvate and glyceraldehyde-3-phosphate.

ISSN:0008-4166    

DOI:10.1139/m58-004

出版商:NRC Research Press    

年代:1958

数据来源: NRC

摘要:

A polysaccharide isolated from cultures ofNocardia asteroidescontained arabinose and galactose in a molar ratio of 1.7:1. The two monosaccharides were unequivocally identified asD-arabinose andD-galactose by isolating them in crystalline form. Partial hydrolysis showed that some of theD-arabinose units in the polysaccharide were in the furanoside ring form while theD-galactose units possessed the pyranoside structure. Methylation studies showed that the polysaccharide was a branched structure ofD-arabinose andD-galactose units with some of the arabinose forming non-reducing, terminal residues. The findings reported here are regarded as further evidence of the close, taxonomic relationship betweenNocardia asteroidesandMycobacterium tuberculosis, members of the same order.

ISSN:0008-4166    

DOI:10.1139/m58-005

出版商:NRC Research Press    

年代:1958

数据来源: NRC

摘要:

Pullularia pullulans, ATCC No. 11942, has constitutive enzymes for the utilization of galactose, glucose, maltose, mannose, raffinose, sucrose, and trehalose, but not for lactose. The organism oxidized mannose more rapidly, and maltose and raffinose more slowly, than any of the other sugars. Moreover, it utilized galactose and glucose at approximately the same rate, but more rapidly than trehalose; the oxidation of sucrose, however, was very slow at first and then very rapid. When resting cells were incubated with glucose-1-C14, the carbon dioxide immediately produced was highly radioactive; when glucose-6-C14was used, however, a considerable time elapsed before the production of noticeable amounts of radioactive carbon dioxide. The ratio of the activity of the carbon dioxide produced from glucose-1-C14to that produced from glucose-6-C14was greater in young cells than in old. The results indicated that resting cells catabolize glucose in such a manner that most of the carbon dioxide comes from carbon 1 of glucose. Extracts from cells were found to have an active phosphoglucomutase, glucose-6-phosphate dehydrogenase, 3-phosphoglyceraldehyde dehydrogenase, and fructose diphosphate aldolase. Both dehydrogenases were TPN-linked. The extracts also oxidized ribose-5-phosphate but not ribose. The organism has enzymes, therefore, to catabolize glucose by some of the reactions of the Embden–Meyerhof system as well as by those of the pentose phosphate cycle.

ISSN:0008-4166    

DOI:10.1139/m58-006

出版商:NRC Research Press    

年代:1958

数据来源: NRC

摘要:

Using the so-called holding technique of pasteurization (61.7 °C., 35 minutes) it was shown that when known numbers of viableListeria monocytogenesare added to samples of fresh sterile milk, organisms may be recovered whenever the initial number of bacteria added is 5 × 104/ml. or greater. No significant differences in heat resistance among representatives of variousListeria monocytogeneswas observed. After 48 hours at room temperature (22 °C.) survivors multiply in such "pasteurized" milk and viable bacterial counts reach 108 per ml. without producing any grossly detectable changes in the milk or suspicious odors.

ISSN:0008-4166    

DOI:10.1139/m58-007

出版商:NRC Research Press    

年代:1958

数据来源: NRC

ISSN:0008-4166    

DOI:10.1139/m58-008

出版商:NRC Research Press    

年代:1958

数据来源: NRC