摘要:

Extracellular polysaccharides were isolated from the blue-green algaAnabaena flos-aquaestrain A-37. The polysaccharides are composed of glucuronic acid, glucose, xylose, and ribose in a molar ratio of 1:88:39:3. The extracellular polysaccharides comprise about 40% of the total carbohydrate produced by this alga.Carbon utilization experiments revealed that onlyD-fructose could be substituted for carbon dioxide as a precursor of polysaccharides and cellular material.The extracellular polysaccharides are derived from water-soluble intracellular polysaccharides of the same composition.Fructose accumulates in stationary phase cells grown in CO2and the presence of the enzymes fructose diphosphate phosphatase and fructose diphosphate aldolase was demonstrated. Tracer studies showed the presence of phosphorylated compounds common to the photosynthetic carbon reduction cycle and the glycolytic pathway.

ISSN:0008-4166    

DOI:10.1139/m65-117

出版商:NRC Research Press    

年代:1965

数据来源: NRC

摘要:

The suppression of infectious bovine rhinotracheitis (IBR) virus multiplication by certain metabolic inhibitors was studied. Viral inhibition with analogues of deoxyuridine and the reversal of this inhibitory effect by thymidine indicates a deoxyribose type of nucleic acid in IBR. Experimental evidence showed no difference in antigenic constitution between IBR and analogue-resistant IBR viruses.

ISSN:0008-4166    

DOI:10.1139/m65-118

出版商:NRC Research Press    

年代:1965

数据来源: NRC

摘要:

A modified chemostat is described which may be used to maintain a continuously phased population in the culture for periods of many months. Preliminary results withCandida utilisshow that changes in the amino acid pool occur over the cell cycle, and that these changes alter with growth rate. The significance of the method and its relationship to chemostat culture are outlined.

ISSN:0008-4166    

DOI:10.1139/m65-119

出版商:NRC Research Press    

年代:1965

数据来源: NRC

摘要:

The activity of the enzyme system which forms acetolactate inEscherichia coliwas found to be greater at both pH 6 and at pH 8 in streptomycin-dependent mutants than in the parent sensitive cultures. The activity of the acetolactate-forming system was observed to be lower in a streptomycin-sensitive revertant than in the dependentE.coliculture from which it was derived by back-mutation. The activity of the acetolactate-forming system from streptomycin-resistant (indifferent) mutants was within the range found for streptomycin-sensitive cultures and was not affected by growth in medium containing dihydrostreptomycin. It was concluded from these observations that excretion ofL-valine by streptomycin-dependentE.coliwas a consequence of the elevated acetolactate-forming activity of these mutants. To explain the (apparently specific) elevation of the acetolactate-forming system in streptomycin-dependent cells, it was postulated that the antibiotic functioned as a de-repressor while pyruvate functioned as the specific enzyme inducer.

ISSN:0008-4166    

DOI:10.1139/m65-120

出版商:NRC Research Press    

年代:1965

数据来源: NRC

摘要:

Penicillium cyaneo-fulvumBiourge, which produces a toxin-neutralizing substance, has been shown to produce a separate and distinct antiviral agent. The two products may be separated in a semipurified state by fractional precipitation with ammonium sulfate and ethyl alcohol.

ISSN:0008-4166    

DOI:10.1139/m65-121

出版商:NRC Research Press    

年代:1965

数据来源: NRC

摘要:

An antiviral substance produced byPenicillium cyaneo-ffulvumBiourge prevents or markedly reduces the infectivity of influenza virus when the two are mixed and inoculated into embryonated eggs, modified Maitland cultures, monkey kidney cell cultures, or mice. It also inhibits mumps and poliomyelitis viruses in embryonated eggs and monkey kidney cell cultures respectively. The effect of influenza virus toxin on HeLa cells is neutralized.

ISSN:0008-4166    

DOI:10.1139/m65-122

出版商:NRC Research Press    

年代:1965

数据来源: NRC

摘要:

Pichia miso, isolated from miso paste, when cultivated in the presence ofD-xylose, produced xylitol,meso-glycero-ido-heptitol, andD-glycero-D-ido-heptitol. This is the first report of the natural occurrence of the two heptitols.

ISSN:0008-4166    

DOI:10.1139/m65-123

出版商:NRC Research Press    

年代:1965

数据来源: NRC

摘要:

not available

ISSN:0008-4166    

DOI:10.1139/m65-124

出版商:NRC Research Press    

年代:1965

数据来源: NRC

摘要:

In vitro growth studies showed thatArthrobotrys oligosporaFresenius,A.conoidesDrechsler,A.musiformisDrechsler, andA.robustaDuddington are characterized by a fast, inherent growth rate relative toA.dactyloidesDrechsler,Dactylella gephyropagaDrechsler, andDactylaria brochopagaDrechsler, which grew slowly on all media tested.Arthrobotrys superbaCorda,Dactylella ellipsosporaGrove, andD.asthenopagaDrechsler were found to be intermediate in this respect. There was little correlation between the maximum rate of increase in colony diameter of the 10 species of nematophagous Hyphomycetes and their ecological requirements for such growth. The fast-growing species appeared to prefer media with a pH range of 5.0–6.0 and the slow-growing fungi a pH of about 4.0. No consistent similarity in environmental requirements was found among species of fungi belonging to the same genus or between those possessing the same kind of nematode-trapping organ. Lima bean agar of pH 5.0 was a satisfactory culture medium and incubation at 25 °C in continuous or intermittent light resulted in larger colonies than incubation in darkness.

ISSN:0008-4166    

DOI:10.1139/m65-125

出版商:NRC Research Press    

年代:1965

数据来源: NRC

摘要:

Both continuous and stationary cultures were used to detect interactions betweenEscherichia coliandPseudomonas aeruginosain mixed cultures, with pure cultures included as controls. The interactions observed were both pH and substrate dependent. Stimulation ofP.aeruginosain mixture was the most marked interaction, and was, in part, due to changes in carbohydrate metabolism.

ISSN:0008-4166    

DOI:10.1139/m65-126

出版商:NRC Research Press    

年代:1965

数据来源: NRC