摘要:

The widespread use of oral contraceptive drugs stimulated an assessment of one such compound for any effects on staphylococci. In vitro turbidimetric studies indicated that norethynodrel in therapeutic doses had a bacteriostatic action on the growth of staphylococci. When adult female mice received 2.5 μg norethynodrel and 1.2 μg mestranol intraperitoneally on each of 3 days before intravenous challenge with virulent staphylococci, the spleens and kidneys of the norethynodrel–mestranol (Enovid) treated mice contained one-half to one-third lower viable staphylococcal counts than those obtained from the same organs of the control mice. Furthermore, during the first several days after infection the Enovid-treated mice showed reduced mortality rates in comparison to those observed in the control mice. Thus, Enovid may affect the development of staphylococcal infections or chemical reactions governing the growth of staphylococci.

ISSN:0008-4166    

DOI:10.1139/m69-045

出版商:NRC Research Press    

年代:1969

数据来源: NRC

摘要:

Tyrosinase activity of the symbionts, and fat bodies of the (Madeira) cockroach,Leucophaea maderae, revealed the following: (a) greatest enzyme synthesis (which decreased upon adolescence) by normal nymphal fat bodies; (b) decreased and somewhat comparable synthesis by aposymbiotic fat bodies; (c) least synthesis by symbiont materials; and (d) definite symbiont enzyme contribution to the pigmentation of the normal insect cuticle.

ISSN:0008-4166    

DOI:10.1139/m69-046

出版商:NRC Research Press    

年代:1969

数据来源: NRC

摘要:

The activity of alcohol dehydrogenase (NAD+-linked) in symbionts, and normal and aposymbiotic fat bodies of the (Madeira) cockroach,Leucophaea maderae, revealed the following: (1) highest concentrations of the enzyme in symbiont materials; (2) lowest concentrations of the enzyme in aposymbiotic fat bodies; (3) comparable concentrations of the enzyme in similar types of fat bodies; (4) possible symbiont contribution of the enzyme to normal insects; and (5) probable inhibition of the symbiont enzyme synthesis in normal tissues.

ISSN:0008-4166    

DOI:10.1139/m69-047

出版商:NRC Research Press    

年代:1969

数据来源: NRC

摘要:

An extracellular complex was isolated from the culture filtrate ofFerrobacillus ferrooxidansgrown on either iron or sulfur. The complex isolated from the culture filtrate of iron-grown cells was red with an absorption maxima at 500–510 mμ. This complex consisted of approximately 60% non-phosphorus lipid. Ferrous iron was exclusively associated with a lipopolysaccharide–phospholipid fraction of the complex. The sulfur complex unlike the iron complex contained approximately 70% phospholipid and was yellowish. On the basis of hexosamine and heptose values, less lipopolysaccharide appeared to be associated with the phospholipid fraction of the complex from sulfur-grown cells than from the iron-grown cells.

ISSN:0008-4166    

DOI:10.1139/m69-048

出版商:NRC Research Press    

年代:1969

数据来源: NRC

摘要:

Neurospora crassais capable of synthesizing two different alcohol dehydrogenases. The synthesis of each depends upon the carbon source on which the mycelium is grown. The fermentative alcohol dehydrogenase, consisting of one electrophoretic protein band, is produced when the mycelium is grown on sucrose. The oxidative alcohol dehydrogenase, consisting of at least two isozymes, is synthesized whenNeurospora crassais grown on ethanol as a sole source of carbon. This latter enzyme is repressed by sugars such as glucose or sucrose. The two enzymes have been differentiated (1) electrophoretically, (2) by their substrate specificity, (3) by the ratio of the forward and reverse reactions, and (4) by their thermostability. Extracts from acetate-grown cells indicate a mixture of the two enzymes.

ISSN:0008-4166    

DOI:10.1139/m69-049

出版商:NRC Research Press    

年代:1969

数据来源: NRC

摘要:

Cultures of fibroblastic cells prepared from chick embryo lung infected with low multiplicities of influenza type A virus strains were found to produce more interferon than did cultures of epithelial cells prepared from the same organ. Fibroblastic cell cultures were also found to be more sensitive to the action of interferon than were epithelial cells with respect to the levels of infectious virus produced and the duration of interferon action. Cultures of the two cell types treated with interferon did not differ with respect to the number of cells involved in virus synthesis.

ISSN:0008-4166    

DOI:10.1139/m69-050

出版商:NRC Research Press    

年代:1969

数据来源: NRC

摘要:

By using selective inhibition of protein synthesis byp-fluorophenylalanine, thienylalanine, or cycloheximide, together with a resuspension technique, it is shown that 6-methylsalicylate synthetase activity ofPenicillium urticaeappears to be due to a metabolically stable enzyme, formed during replicatory growth, and becoming active later as a consequence of increases in substrate levels. In the same fungus, the conversion of 6-methylsalicylate into gentisaldehyde and patulin involves metabolically labile enzymes, which are formed later in the culture development. Regulation of the synthesis of these later enzymes may involve both induction in the presence of substrate and repression by high nutrient levels.

ISSN:0008-4166    

DOI:10.1139/m69-051

出版商:NRC Research Press    

年代:1969

数据来源: NRC

摘要:

Despite the initial inhibition of growth, stepwise adaptation to fluoride was observed by strains ofStreptococcus salivariusincubated in glucose–tryptone broth with NaF at concentrations as high as 14.3 mM. In medium at a variety of NaF levels up to 4.8 mM, the specific growth rates, for control cells never exposed to fluoride and for stepwise adapted strains were similar, but the rates for both cell types decreased inversely with the fluoride concentration in the medium. The lag period for the fluoride-adapted strains, however, was much shorter than the control (0-F) cells. On the other hand, when compared to stepwise adapted cells, ultraviolet-induced mutants resistant to similar levels of NaF gave higher growth rates and maximum growth values, and shorter lag periods. Furthermore, the yield of cell material per gram of glucose for the ultraviolet-induced strains was always higher, even at NaF concentrations twice that used for selection. The stoichiometry of glucose degradation to lactic acid by the ultraviolet-induced strains resembled that of the wild-type parent, while the adapted cells produced less lactic acid per mole of glucose. Despite the differences in growth and metabolic characteristics of the adapted and ultraviolet-induced mutants, both types of cells retained their resistance to fluoride even after passage for 500 generations in medium free of sodium fluoride.

ISSN:0008-4166    

DOI:10.1139/m69-052

出版商:NRC Research Press    

年代:1969

数据来源: NRC

摘要:

A scheme has been devised to facilitate the identification of aerobic heterotrophic soil bacteria to generic level using Skerman's key. Tests used in the scheme have been modified from those originally described to allow use, where possible, of multipoint inoculation techniques. Modified tests have been compared with those originally described and in all cases the use of modified tests was justified. Although there was no saving in length of time needed to identify any one isolate there was considerable saving in the number of manipulations required and more isolates could be handled in the time.

ISSN:0008-4166    

DOI:10.1139/m69-053

出版商:NRC Research Press    

年代:1969

数据来源: NRC

摘要:

Four molds (Aspergillus fumigatus,A.terreus,A.niger,Penicilliumspecies) and aStreptomycesspecies capable of degrading catechin were isolated from soil by enrichment techniques. These organisms andAspergillus flavus(dicat), isolated from a dicatechin medium, were compared for their ability to degrade catechin. The studies indicated thatA.flavus(dicat) was the most active of the organisms tested. The degradation of catechin byA.flavus(dicat) was optimal at pH 5.0 and 0.3% catechin. Phloroglucinol carboxylic acid and protocatechuic acid were identified as products of the degradation.

ISSN:0008-4166    

DOI:10.1139/m69-054

出版商:NRC Research Press    

年代:1969

数据来源: NRC