摘要:

Resting cell and cell-free extract experiments demonstrated the presence of citritase, oxaloacetic acid decarboxylase, α-acetolactic acid decarboxylase, and pyruvic acid decarboxylase inStreptococcus diacelilactis. Results indicated that citric acid or pyruvic acid was converted to diacetyl and acetylmethylcarbinol with intermediate synthesis of α-acetolactic acid. Acetylmethylcarbinol also was synthesized by condensation of active and free acetaldehyde. Evidence was obtained for the presence of diacetyl reductase and a reversible 2,3-butanediol dehydrogenase in cell-free extracts ofS.diacetilactis. The data suggested thatS.diacetilactisproduced diacetyl from citrate with the intermediate production of oxaloacetate, pyruvate, and α-acetolactate in that order.

ISSN:0008-4166    

DOI:10.1139/m63-056

出版商:NRC Research Press    

年代:1963

数据来源: NRC

摘要:

Employing potassium tellurite, sodium azide, and thallium acetate broths, 361 strains of fecal streptococci were isolated from 142 farm animals representing 11 species. Although none of the three media gave 100% recovery, their collective use made it possible to obtain at least one fecal streptococcus strain from every fecal sample.Results of biochemical tests revealed that 14.8% wereS.bovis, 12.7% wereS.faecalisvar.liquifaciens, and the remaining 72.5% were atypical faecalis groups.Using the 361 isolates from animal fecal material for validating the heat resistance and heat-tellurite tolerance tests for the differentiation between animal and human fecal streptococci strains, it was found that not one of these isolates could survive these combined tests. The importance of these tests is discussed.

ISSN:0008-4166    

DOI:10.1139/m63-057

出版商:NRC Research Press    

年代:1963

数据来源: NRC

摘要:

A species ofPythium(probablyP.acanthicumDrechs.) is described which is able to parasitize 80% of a wide range of 98 species of fungi tested. Nine of the test fungi were not parasitized, and 10 actively inhibited thePythium, withUstilago maydisexhibiting the strongest inhibition. The roots of sunflower, corn, wheat, flax, beet, morning glory, sweet pea, Polish rape, and green pea were attacked, producing browning of the root tips. The organism produced a rapid, watery soft rot when inoculated into cucumber and potatoes. The organism requires a fat-solvent extractable substance for development of its sexual stages. It can obtain this substance from both living and dead host tissues, but not from its own killed vegetative mycelium.

ISSN:0008-4166    

DOI:10.1139/m63-058

出版商:NRC Research Press    

年代:1963

数据来源: NRC

摘要:

Qualitative and quantitative procedures were used to demonstrate phosphorylase activity inStylonychia pustulata. The enzyme did not require divalent metal cations for activity; however, Mn2+, Ca2+, Co2+, and Zn3+enhanced the activity. The enzyme was inhibited by Sr2+, Ba2+, Ni2+, Cd2+, Fe2+, Sn2+, Hg2+, Pb2+, and Cu2+. The most effective inhibitor was Sr2+, which produced about 57% inhibition. The enzyme was more active at a pH of 6.2 than at a pH of 7.2, 8.2, or 9.2. The optimum temperature for activity was about 30°. The homogenates of the animals were found to contain 0.053 μg of glycogen/μg of proteinN.The intracellular distribution of the enzyme in the animals could not be determined by the histochemical techniques used in these experiments.

ISSN:0008-4166    

DOI:10.1139/m63-059

出版商:NRC Research Press    

年代:1963

数据来源: NRC

摘要:

The development and significance of the enlarged 'cystite' forms ofArthrobacter globiformisandArthrobacter pascenshave been investigated. It was found that pure populations of cystites could be grown by introducing inoculum from a rich medium into a minimal medium. The enlarged cells produced under these conditions ranged from two to four times the size of the small coccoid forms typical of old cultures ofArthrobacter. When these cystite forms were transferred to an adequate medium, initial growth appeared like the germ tubes of fungal spores. Continued growth resulted in the formation of cross walls with subsequent fragmentation. Successive divisions brought about a gradual decrease in fragment size until the small coccoid cells typical of the stationary phase cells are formed. The results suggest that the cystites are really morphologically aberrant forms which are produced at the time of nutritional stress. No evidence was found to support the theories that cystites are specialized spore forms.

ISSN:0008-4166    

DOI:10.1139/m63-060

出版商:NRC Research Press    

年代:1963

数据来源: NRC

摘要:

FromListeria monocytogenescultured at 4 °C and at 37 °C, a lipid fraction called monocytosis-producing-agent (M.P.A.) was extracted. From the cells cultured at 4 °C, twice as much M.P.A. was obtained per unit of dry weight cells. M.P.A. obtained from cells cultured at 4 °C was as effective as the one isolated from cells grown at 37 °C in stimulating monocytes production in rabbits. The time of incubation at 4 °C was varied from 5 to 10 days without significant difference in cell yield. Extraction of M.P.A. was neither quantitatively nor qualitatively enhanced by sonic oscillations at 8000 cycles. Such treatment of dead cells for as long as 105 minutes failed completely to disintegrate the organisms. Further destruction of the cell walls by sonic oscillation or shaking with glass beads contributed little to the overall yield of M.P.A.

ISSN:0008-4166    

DOI:10.1139/m63-061

出版商:NRC Research Press    

年代:1963

数据来源: NRC

摘要:

A fluffy white mycelial variant of low pathogenicity developed from the normal sporulating pathogenic fungusDrechslera teresgrowing on P.D.A., V-8 agar, M.Y.A., and Czapek agar. Factors such as the amount and type of carbon and nitrogen compounds present influenced the production of the mycelial variant, which was less virulent than the original isolates.The two forms of this fungus differed in the amount of growth according to temperatures, pH values of the media, and nutritional conditions. The mycelial form arose more frequently in conidial cultures grown in media of a high sugar content. Growth of the conidial form was not so good as that of the mycelial form on media containing amino acids.There was some loss of pathogenicity of the conidial culture after it had been grown and transferred eight consecutive times on media containing methionine, cysteine, or asparagine. The pathogenicity of the mycelial form was unaltered regardless of its nutrition.Factors which lead to the development of the mycelial variant are discussed.

ISSN:0008-4166    

DOI:10.1139/m63-062

出版商:NRC Research Press    

年代:1963

数据来源: NRC

摘要:

Cells ofMicrococcus kalodenitrificans, a moderate halophile, contain poly-β-hydroxybutyric acid (PHBA), which is oxidized endogenously when cells are suspended in NaCl. The oxidation involves a depolymerase, a DPN-linkedD(−)-β-hydroxybutyric acid (HBA) dehydrogenase, and the enzymes of the tricarboxylic acid cycle. Cells suspended in NaBr, Na2SO4, Li2SO4, and LiCl oxidize PHBA but cells suspended in KCl, KBr, K2SO4, MgCl2, CaCl2, CsCl, glucose, or glycerol, iso-osmotic with 0.4 molal NaCl or in water or buffers do not. Since cells washed with and resuspended in KCl do not oxidize their internal PHBA, it seems that nearly all the cell Na+has been replaced by K+. These cells can be reactivated by the addition of Na+or Li+, indicating that these ions are required for enzyme activity. In Na-depleted cells or their extracts the dehydrogenation of HBA and the oxidation of acetate are unimpaired, but there is no PHBA depolymerase activity. PHBA depolymerase can be reactivated by the addition of Na+. The results indicate that sodium or lithium salts readily penetrate the cells ofM.halodenitrificansand are required to activate the PHBA depolymerase.

ISSN:0008-4166    

DOI:10.1139/m63-063

出版商:NRC Research Press    

年代:1963

数据来源: NRC

摘要:

An investigation of 110 cultures of Gram-negative bacteria which failed to produce acid in conventional carbohydrate media was undertaken to determine their taxonomic position.Thirty-seven strains had peritrichous flagella, 30 were monotrichous, 8 were lophotrichous, 3 were either monotrichous or lophotrichous, and 32 strains were non-flagellated.Flagella stains and reaction in Hugh and Leifson"s O/F medium were used to divide the strains into general groups.Sixty-five strains were inert in O/F medium. Forty of these resembled the general description for the genusAlcaligenes. Seventeen strains resembledAlcaligenesbiochemically, but were either monotrichously or lophotrichously flagellated. Several strains resembledVibrio percolans.Nine strains resembledAchromobacterbiochemically by oxidatively utilizing pentoses only.Twenty-three strains resembledPseudomonas aeruginosa. All produced acid oxidatively in the O/F medium.Thirteen strains produced acid fermentatively in O/F medium.Serological studies indicated antigenic heterogeneity. Several strains shared flagellar and somatic antigens, while others were related by either somatic or flagellar components. Seventy-eight strains did not react with any somatic antisera and 54 strains did not react with any flagellar antisera. There was little correlation between antigenicity and biochemical or morphological characteristics.

ISSN:0008-4166    

DOI:10.1139/m63-064

出版商:NRC Research Press    

年代:1963

数据来源: NRC

摘要:

A quantitative study was undertaken to characterize the cell walls ofArthrobacter globiformis. Varying amounts of galactose, galactosamine, glucosamine, and muramic acid were found, depending on the strain of the organism, the growth medium, and the stage of growth of the cells. The data indicated that walls obtained from pleomorphic cells are less highly polymerized than are those obtained from coccoid cells. Examination of isolated wall polysaccharide showed a wide variation in the galactose content.

ISSN:0008-4166    

DOI:10.1139/m63-065

出版商:NRC Research Press    

年代:1963

数据来源: NRC