摘要:

Actinophage SAP2 could infect, replicate in, and lyseStreptomyces aureofaciensat 27 °C and 37 °C. The phage attached to, and killed, the host at 42 °C but no new phage particles were produced. Phage-infected mycelia incubated at 42 °C for 2 h, and then lysed with lysozyme, did not contain viable actinophage particles. Viral yields were markedly decreased when phage-infected cultures were exposed to 42 °C during the first quarter or last quarter of the latent period. Phage lysates prepared at 37 °C contained less halo-producing lysin than those prepared at 27 °C. The data suggest that elevated temperatures affect an early event during the latent period and also suppress lysin production.

ISSN:0008-4166    

DOI:10.1139/m67-207

出版商:NRC Research Press    

年代:1967

数据来源: NRC

摘要:

Like sporidesmin, gliotoxin catalyzes the decomposition of azide in the presence of iodine, and this catalysis can be used for its estimation. The presence of respiring cells ofBacillus subtilisdoes not interfere with the estimation. Thus it was possible to show that the concentration of gliotoxin decreased when solutions of the antibiotic were incubated with respiring cells. The rate of the decomposition was independent of the gliotoxin concentration in the range 2–25 μg/ml, but was dependent on the number of cells, the pH, and the available nitrogen in the suspending medium. Loss of gliotoxin was most rapid at pH 5.5 and continued when the supernatant was reincubated after centrifugal removal of the cells. No loss of gliotoxin occurred when solutions were incubated in the absence of cells at pH 5.5. By contrast, chemical degradation at pH 8.0 was inhibited in the presence of cells. These results are consistent with the hypothesis thatB.subtilissecretes an enzyme which degrades the disulfide group in gliotoxin.

ISSN:0008-4166    

DOI:10.1139/m67-208

出版商:NRC Research Press    

年代:1967

数据来源: NRC

摘要:

Cell envelopes from logarithmic phase cells of eight strains ofAgrobacterium tumefacienswere isolated and examined qualitatively and quantitatively for various components. Envelopes, 6 to 9% of the total dry weight of the bacteria, were composed of approximately 23 to 27% lipid, 3.1 to 6.0% total nitrogen, and 6.3 to 11.2% carbohydrates. Cytochrome was present in envelopes obtained from logarithmic phase cells.The glycosaminopeptide was composed of glutamic acid, alanine, 2,6-diaminopimelic acid, and amino sugars. Leucine, phenylalanine, serine, and aspartic acid were found in relatively high levels in several of the strains investigated.In addition to ubiquinones, four phospholipids, phosphatidylethanolamine, phosphatidyl-N-methylethanolamine, phosphatidyl-N,N-dimethylethanolamine, and phosphatidyl-choline, were observed in the lipid fraction of all eight strains ofA.tumefaciensexamined.Glucose, fucose, and 2-keto-3-deoxyoctulosonic acid were present in the lipopolysaccharide of all strains tested.There appears to be no correlation between the virulence of this plant pathogen and the mucopeptide or lipid–protein–polysaccharide components of the cell envelope.

ISSN:0008-4166    

DOI:10.1139/m67-209

出版商:NRC Research Press    

年代:1967

数据来源: NRC

摘要:

Lipopolysaccharides have been isolated from seven species of Gram-negative bacteria and their acid hydrolysates have been examined by gas–liquid partition chromatography for the presence of aldoheptoses. All containedD-glycero-D-manno-heptosein addition to the well-known aldoheptose componentL-glycero-D-manno-heptose. The relative proportions of these two aldoheptoses varied widely between species of bacteria and to a lesser extent between members of the same species. Both aldoheptoses were isolated from a lipopolysaccharide prepared fromE.colicells and were positively identified by physical and chemical methods. The chromatographic method used for determining the aldoheptoses also provided means for simultaneous detection of 3-deoxy-D-manno-octulosonic acid (KDO).

ISSN:0008-4166    

DOI:10.1139/m67-210

出版商:NRC Research Press    

年代:1967

数据来源: NRC

摘要:

The present study was initiated to determine the amount of glycopeptide synthesized during sporulation ofBacillus megaterium. The glycopeptide fraction was isolated quantitatively from vegetative cells, sporulated cells, and free spores, and then assayed for amino sugars. The yields of glycopeptide hexosamine (GPH) in these preparations were compared on the basis of number of cells. During the early stationary phase of cultural growth, cells continued to synthesize cell wall material even though they did not divide or increase in size significantly. In the sporulation medium GPH synthesis was synchronized with the development of the endospore within the bacilli. During this period GPH formation occurred at an increased rate. Synthesis terminated as free spores were liberated from their sporangia. The total amount of GPH synthesized in the sporulating bacilli could be accounted for in the cleaned, free spores.

ISSN:0008-4166    

DOI:10.1139/m67-211

出版商:NRC Research Press    

年代:1967

数据来源: NRC

摘要:

Both the pathogenLeptospira pomonaand the saprophyteL.biflexaPatoc I can convert exogenous adenine, guanine, and 8-azaguanine to the corresponding nucleotide and incorporate them into nucleic acids.L.pomonais inhibited by low concentrations of 8-azaguanine (50 μg/ml) and this inhibition is associated with less than a 5% replacement of the ribonucleic acid (RNA) guanine residues by the analogue. Guanine possessed the highest activity for antagonizing the inhibitory effect of 8-azaguanine. The biosynthetic process ofL.pomonamost affected by the analogue was a relative increase in RNA synthesis. The analogue-resistantL.biflexaincorporated 1/10 as much 8-azaguanine asL.pomona. The higher rate of purine biosynthesis, in addition to the lesser amount of 8-azaguanine incorporated, may account for the analogue resistance ofL.biflexa.

ISSN:0008-4166    

DOI:10.1139/m67-212

出版商:NRC Research Press    

年代:1967

数据来源: NRC

摘要:

The cell-free filtrate of a liquid culture ofAureobasidium pullulans(de Bary) Arnaud contained a substance which stimulated the growth ofArmillaria niellea(Fr.) Quél. This stimulatory effect was apparent when either rhizomorph tips or undifferentiated mycelium on water agar discs were used as inoculum, indicating an effect on both rhizomorph initiation and elongation. The cell-free filtrate was shown by gas chromatography to contain ethanol. Ethanol had an effect on the growth ofA.melleasimilar to that of the cell-free filtrate.Growth ofA.melleawas stimulated by the presence of ethanol in the medium and the degree of stimulation was shown to be dependent on the total amount of ethanol available at a concentration of 500 p.p.m. Ethanol added at regular intervals as lower concentrations in the medium stimulated the growth ofA.melleaas much as one higher initial concentration. A concentration of ethanol as low as 50 p.p.m. added daily for 14 days was more effective than an initial concentration of 700 p.p.m. in stimulating rhizomorph development ofA.mellea.

ISSN:0008-4166    

DOI:10.1139/m67-213

出版商:NRC Research Press    

年代:1967

数据来源: NRC

摘要:

Greater amounts of intracellularly bound glucans were present inEscherichia coli, strain B/r cells, in the late lag and logarithmic growth phases than in cells in the early lag and stationary growth phases. Bound alkali-stable and alkali-labile glucose-containing polymers— as well as unbound glucans—were further characterized by their susceptibility to hydrolysis by alpha-amylase and by their trichloroacetic acid (TCA) – ethanol solubility characteristics. A combination of phenol/water fractionation and TCA–ethanol partitioning of acetone-dried cells revealed the presence of bound glucose-containing polymers in the crude lipopolysaccharide, protein, DNA, and RNA subcellular fractions.Purified lipopolysaccharides fromEscherichia coli, strains B, B/r, and Bs, contained both alkali-stable and alkali-labile glucose polymers. Similarly, alkaline hydrolysis and TCA–ethanol partitioning of both phenol- and TCA-extracted endotoxin preparations yielded numerous carbohydrate-containing subfractions. The carbohydrate monomers associated with lipopolysaccharide fractions ofEscherichiaspecies were more susceptible to alkaline degradation than the monomeric constituents present inSalmonellaandShigellalipopolysaccharide preparations. Upon exposure to either hydrolytic enzymes or gelatin, the phenol-extracted lipopolysaccharides were further partitioned into numerous lipopolysaccharide- and (or) homopolysaccharide–biopolymeric complexes by TCA-ethanol fractionation.

ISSN:0008-4166    

DOI:10.1139/m67-214

出版商:NRC Research Press    

年代:1967

数据来源: NRC

摘要:

Gallotannin, wattle, canaigre, and chestnut tannins in a complete medium affected in vitro spore germination and mycelial growth ofFusarium solanif.phaseoliandVerticillium albo-atrum. The pH values and tannin concentration were important factors determining the effectiveness of tannins as inhibitors. Under acidic conditions (pH 5), gallotannin, canaigre, and chestnut tannins at concentrations varying from 39 p.p.m. to 625 p.p.m. inhibited spore germination of both fungi. At a concentration of 1000 p.p.m. these tannins completely prevented growth at pH 5 of both fungi during a 20-day period. Under near neutral conditions (pH 6–7) there was a minimum inhibition of spore germination and mycelial growth with all tannins tested. Under alkaline conditions (pH 8) there was some degree of inhibition of spore germination, but, in general, growth was similar to that under neutral conditions. Wattle tannin was unusual in that it did not prevent growth of either fungus under acidic conditions although the growth ofV.albo-atrumwas appreciably reduced compared with the control. Gallotannin, however, prevented growth of both fungi under alkaline as well as acidic conditions.

ISSN:0008-4166    

DOI:10.1139/m67-215

出版商:NRC Research Press    

年代:1967

数据来源: NRC

摘要:

The mycelial growth ofSchizophyllum communeon cellobiose, as sole carbon source, produced colonies that were quite dense and restricted in diameter. The hyphae were composed of shorter, more highly branched cells when grown on this disaccharide. Cellobiose brought about an increase in the ratio of an alkali-soluble cell-wall fraction (S-glucan) to an alkali-insoluble cell-wall fraction (R-glucan). This change might be explained by increased activity of enzymes which hydrolyze the R-glucan component following growth in cellobiose. Thus, a system is described which attempts to relate wall-softening enzymes to morphology.

ISSN:0008-4166    

DOI:10.1139/m67-216

出版商:NRC Research Press    

年代:1967

数据来源: NRC