摘要:

A relatively quick and convenient electrophoretic method, capable of separating and partially purifying soluble enzymes from cell-free extracts, is described. The method presented has the feature of analytical applicability and is ideally used with preparatory amounts of material. This zonal technique was developed with the Svensson-Porath preparatory electrophoresis column by using Sephadex G-25 as the anticonvectant. TheD(−)β-hydroxybutyric and isocitric dehydrogenases ofAzotobacter vinelandiistrain O were used as the marker enzymes, and both were resolved as sharply defined peaks. The combined use of ammonium sulfate fractionation and electrophoresis yielded highly active and partially purified enzyme preparations of the β-hydroxybutyric and isocitric dehydrogenases.

ISSN:0008-4166    

DOI:10.1139/m69-060

出版商:NRC Research Press    

年代:1969

数据来源: NRC

摘要:

Preferential cell wall synthesis inMicrococcus lysodeikticus, as determined by an increase in the dry weight of the cell wall, took place in a medium containingDL-glutamic acid,DL-alanine,L-lysine, glycine, magnesium ions, glucose and phosphate buffer, pH 7.0. Cell wall synthesis could not be completely dissociated from protein synthesis in the 'cell wall' medium. The cell wall synthesized in the defined medium accounted for 40–56% of the total dry weight increase of the cells. Chloramphenicol had no effect on cell wall synthesis. Incorporation of uracil and guanine in the medium did not result in any increase in the amount of cell wall synthesized.DL-Glutamic acid alone, or a mixture of the three amino acidsDL-alanine,L-lysine, and glycine, were capable of replacing the four amino acids present in the complete medium, but under these conditions the total dry weight of cell wall synthesized was only 75% of that produced in the complete medium. There was no reduction in cell wall synthesis whenL-glutamic acid replacedDL-glutamic acid,L-alanine replacedDL-alanine, or sucrose replaced glucose in the cell wall medium. Deprivation of magnesium ions produced the greatest decrease in wall synthesis; this was the most important single factor involved in cell wall synthesis which was studied in the present investigation. There was no observable change in the chemical composition of the cell wall synthesized in the 'wall' medium when compared to that synthesized by cells grown in a complex medium.

ISSN:0008-4166    

DOI:10.1139/m69-061

出版商:NRC Research Press    

年代:1969

数据来源: NRC

摘要:

The guanine + cytosine contents (%(G + C)) of DNAs from 75 strains of asaccharolyticNeisseria,Moraxella, andAcinetobacterhave been determined by measuring their buoyant densities in the CsCl gradient. The main purpose was to provide supporting evidence for taxonomic conclusions based on assay of genetic transformation to streptomycin resistance among the same strains and species.Three groups of neisseriae can be recognized, both by determination of %(G + C) and by transformation assay: (i)Neisseria flavescensandN.cinerea(46.5–49%), (ii)N.catarrhalis(41–42.5%), and (iii)N.caviaeandN.ovis(44.5–45%). There is no transformation compatibility between group (i) and the other groups, whereas groups (ii) and (iii) show mutual transformation interactions.N.catarrhalis,N.caviae, andN.ovis, therefore, can also be considered as one group of nonpigmented, asaccharolytic neisseriae.Four groups of moraxellae can be distinguished: (i)Moraxella nonliquefaciens,M.lacunata,M.liquefaciens, andM.bovis(40–43%), (ii)M.osloensis(43–43.5%), (iii)M.phenylpyrouvica(43–43.5%), and (iv)M.kingii(44.5%). Although groups (ii) and (iii) are identical in terms of %(G + C), they exhibit low transformation compatibility, of the same order as between groups (i) and (ii). The distinctly higher G + C content ofM.kingiiDNA is consistent with its lack of transformation compatibility with other moraxellae.The similar %(G + C) range for the moraxellae and the nonpigmented, asaccharolytic neisseriae is consistent with the finding of some transformation compatibility between most of these organisms (exceptM.kingii) and provides additional support for the assumption that they are closely related.TheAcinetobacterstrains studied exhibit a wide range of G + C contents (38–45%) and hardly any transformation compatibility with neisseriae and moraxellae, even if some of them have matching %(G + C).It can be concluded that determination of the G + C contents of bacterial DNAs provides useful supplementary taxonomic data, but has only limited value as a sole taxonomic criterion.

ISSN:0008-4166    

DOI:10.1139/m69-062

出版商:NRC Research Press    

年代:1969

数据来源: NRC

摘要:

A subcellular amino-acid-incorporating system from the obligately psychrophilic yeast,Candida gelida, was completely inhibited after incubation at 35 C for 30 minutes. The thermal inactivation of protein synthesis was due, in part, to the presence of unusually temperature-sensitive aminoacyl-sRNA synthetases inC.gelidaextracts. Of the 13 specific synthetases examined, 7 retained less than 50% of their activity after being held at 35 C for 30 minutes. Kinetic studies of thermal inactivation of leucyl-sRNA synthetase demonstrated that this enzyme is 50% inactivated after only 7 minutes at 35 C. None of the 10 sRNA species tested was temperature sensitive. In addition to temperature-sensitive synthetases,C.gelidapossesses thermolabile soluble enzymes involved in the formation of ribosomal-bound polypeptide chains.

ISSN:0008-4166    

DOI:10.1139/m69-063

出版商:NRC Research Press    

年代:1969

数据来源: NRC

摘要:

Chemoautotrophic sulfur bacteria were isolated in pure form from estuarine, neritic, and oceanic environments by the use of small-volume enrichment cultures. Thiosulfate was the only energy source added to the medium. Bicarbonate and carbon dioxide were the carbon sources.The bacteria were found in seawater samples collected at the surface and at a depth of 30 meters. Clay and mud sediments contained chemoautotrophs and heterotrophic pseudomonads with the capacity to oxidize thiosulfate.The isolated microorganisms differed greatly in their morphologies. Cells ranged in shape from vibrios to several varieties of rods which occurred alone, in pairs, in long chains, and in clusters. All of the bacteria were aerobic, Gram-negative, and non-sporulating.Growth characteristics with respect to the formation of elemental sulfur, production of tetrathionate, and final pH varied markedly. Colonies on thiosulfate – mineral salts agar were all 1 mm or less in diameter. A test, of two of the chemoautotrophs indicated a need for seawater in the growth medium.Out of a total of six different chemoautotrophic bacteria, one was identified as a strain ofThiobacillus thioparus. Another was facultatively autotrophic. The other four types were not compatible with the descriptions of any of the known thiobacilli.

ISSN:0008-4166    

DOI:10.1139/m69-064

出版商:NRC Research Press    

年代:1969

数据来源: NRC

摘要:

Marine strain D10-B, a Gram-negative, non-motile, facultative chemoautotrophic sulfur bacterium, oxidized thiosulfate to sulfate with the production of energy which was used for14CO2fixation. The assimilation of14CO2was almost completely inhibited by 5 × 10−4 M2,4-dinitrophenol. Thiosulfate oxidation was inhibited by 47% in the presence of 5 × 10−4 M KCN. The thiosulfate-oxidizing system appeared to be inducible. Elemental sulfur, sulfite, and tetrathionate were also respired, but only thiosulfate served as a substrate for growth. Strain D10-B grew heterotrophically on a variety of single and complex organic substrates. The organism was compared toThiobacillus novellusandThiobacillus intermedins. It was classified as a marine strain ofT.novellus.

ISSN:0008-4166    

DOI:10.1139/m69-065

出版商:NRC Research Press    

年代:1969

数据来源: NRC

摘要:

Eighty-three bacteria, from a total of 1091, isolated from the rhizoplane of inoculated pasture clovers, inhibited the growth of twoRhizobium trifoliistrains. The antagonists belonged to the generaPseudomonas,Xanthomonas,Achromobacter,Flavobacterium,Alcaligenes,Erwinia,Aerobacter,Bacillus,Streptomyces,Nocardia,Corynebacterium,Arthrobacter, andBrevibacterium. Most, as well as the strongest, antagonists were confined toPseudomonas. Two distinct groups were recognized within this genus. The A and B groups produced pink water soluble and green fluorescent pigments, respectively.

ISSN:0008-4166    

DOI:10.1139/m69-066

出版商:NRC Research Press    

年代:1969

数据来源: NRC

摘要:

Lipopolysaccharides (LPS) prepared fromN.catarrhaliscells were separated into a chloroform-soluble fraction (26%) and a chloroform-insoluble fraction (74%). Both LPS fractions containedD-glucose,D-galactose,D-glucosamine, galactosamine, lipid A, ethanolamine, fatty acids, acetyl, phosphate, and protein in approximately equal proportions. The lipid A moieties prepared from the two LPS fractions were also similar in composition to each other. The fatty acids and galactosamine of the LPS fractions were recovered quantitatively in their lipid A fractions. The major fatty acid component was β-hydroxylauric acid in contrast with β-hydroxymyristic acid, which is the major fatty acid component of the lipid A ofN.perflavaand other Gram-negative bacteria. The lipid A ofN.catarrhalisalso contained a considerable amount ofD-glucose andD-galactose, which are not normal constituents of lipid A fractions. The presence of amino acids (ca. 2%) in all fractions suggested that proteins were an integral part of the LPS molecules. The absence of heptose and 3-deoxyoctulosonic acid (KDO) from theN.catarrhalisLPS shows that it lacks a lipopolysaccharide "core" structure similar to that present in the LPS ofN.perflava; the polysaccharide part of the LPS molecule is also compositionally different from that ofN.perflava. These differences may provide additional evidence to that already accumulated from other sources thatN.catarrhalisis taxonomically a "false neisseria".

ISSN:0008-4166    

DOI:10.1139/m69-067

出版商:NRC Research Press    

年代:1969

数据来源: NRC

摘要:

The proton magnetic resonance (p.m.r.) spectra of the mannans extracted from a number of species ofHansenulaandPichiawere determined, and the species in each genus grouped according to similarities in the p.m.r. spectra. Some of the groups ofPichiaspecies formed mannans having similar spectra to those produced by some species ofHansenula. SeveralCandidaspecies produced mannans having spectra similar to those ofPichiaspecies.Pichia vanrijiiformed a mannan whose spectrum resembled the spectra of the mannans formed bySchwanniomycesspecies.Pachysolen tannophilusformed a mannan with a spectrum resembling those ofHansenula holstiiandHansenula capsulata. Citeromyces matritensisand its asporogenous formTorulopsis globosaformed mannans unlike those of any other yeast studied.

ISSN:0008-4166    

DOI:10.1139/m69-068

出版商:NRC Research Press    

年代:1969

数据来源: NRC

摘要:

Micrococcus sodonensiscan metabolize glucose to carbon dioxide and water via both the hexose monophosphate shunt and glycolysis but cannot use it as a sole source of carbon and energy. When lactate-grown cells ofM.sodonensisare replaced on glucose there is a 50% increase in cell population. The synthesis of deoxyribonucleic acid, ribonucleic acid, and protein continues for about 1.5 to 2.0 h before it ceases. Cells replaced in lactate medium under the same conditions double in number in approximately 4 h. Cells replaced in glucose do not synthesize phosphorus-containing compounds as ascertained by inorganic phosphate uptake while lactate-utilizing cells take up phosphate at a significant and continuous rate. The results suggest that the inability to utilize glucose as a sole source of carbon and energy is related to this incapability ofM.sodonensisto gain sufficient energy from glucose oxidation. Results with related strains of micrococci suggest this phenomenon may be widespread in this group of microorganisms.

ISSN:0008-4166    

DOI:10.1139/m69-069

出版商:NRC Research Press    

年代:1969

数据来源: NRC