摘要:

Chlorate inhibited the aerobic growth ofEscherichia coliK12 in at least two ways, here termed type I and type II inhibition. Type I inhibition was reversed by shikimic acid or by a group of four amino acids (tyrosine, phenylalanine, tryptophane, and methionine), or by nitrate at much higher concentrations. Type I inhibition involved the metabolism of chlorate via nitrate reductase to a toxic form which apparently interfered with aromatic amino acid biosynthesis. The occurrence of type I inhibition is affected by the particular carbon and energy source supplied. Type II inhibition involved chlorate itself, or a derivative not formed by nitrate reductase. The extent of the inhibition was affected byL-serine, methionine, and sodium formate.

ISSN:0008-4166    

DOI:10.1139/m74-011

出版商:NRC Research Press    

年代:1974

数据来源: NRC

摘要:

Two media for preserving the viability of different viruses in clinical material during transit at ambient temperature have been developed. One was designed for transporting stool specimens and autopsy material, while the other was designed for such specimens as throat washings, swabs, and cerebrospinal fluid. The essential ingredient in both media was bentonite either uncoated or coated with serum proteins. Preparation of both media is given in detail.Experimental results presented indicate that coxsackie A9, B5, echo 11, adeno 5, influenza A2, parainfluenza, rubella, and herpes simplex viruses could sustain their infectivity without loss of titer in bentonite transport medium for prolonged time, from 3 to 21 days, depending on the virus type.The bentonite transport medium was found to be superior to commonly used charcoal viral transport medium.

ISSN:0008-4166    

DOI:10.1139/m74-012

出版商:NRC Research Press    

年代:1974

数据来源: NRC

摘要:

Micrococcus sodonensishas been shown to produce several extracellular enzymes: an alkaline phosphatase, at least two forms of phosphodiesterase, a 5′-nucleotidase, and an alkaline proteinase. The quantitative release of these enzymes into the culture medium during logarithmic growth under all the various culture conditions tested indicates that these enzymes are truly extracellular in nature. Inorganic phosphate repressed the production of the alkaline phosphatase in synthetic as well as in complex media, whereas, the repression of the production of active diesterase and 5′-nucleotidase by inorganic phosphate was partly reversed by the addition of supplemental organic nutrients to the culture medium. Proteinase production was independent of the culture conditions used. A mutant strain ofM.sodonensiswith an altered production of diesterase was obtained; the other extracellular enzymes were unaffected. These results suggest that the extracellular enzymes ofM.sodonensisare not produced in a pleiotropic fashion since the level of one of the enzymes can be changed without affecting a corresponding change in the levels of the other enzymes. An extracellular high molecular weight carbohydrate fraction was shown to be produced byM.sodonensisin synthetic medium. The fraction was also shown to contain glycoprotein.

ISSN:0008-4166    

DOI:10.1139/m74-013

出版商:NRC Research Press    

年代:1974

数据来源: NRC

摘要:

The production of mycelium and conidia ofPenicillium clavigerumandPenicillium claviformeis severely restricted if an amino acid is not present in a maltose–mineral salts medium. This requirement can be satisfied by anyL-amino acid, although the optimum quantity varies with the type of amino acid. When ammonium–nitrogen is substituted for nitrate–nitrogen or amino acid–nitrogen in theP.clavigerummedium, the formation of coremia and conidia is prevented, mycelial growth is inhibited, and an orange intracellular pigment is produced. The numbers of coremia and conidia produced by both organisms are regulated by the quantity of manganese in the media.

ISSN:0008-4166    

DOI:10.1139/m74-014

出版商:NRC Research Press    

年代:1974

数据来源: NRC

摘要:

Fusarium oxysporumf.conglutinans,Gelasinospora cerealis,Penicillium viridicatum,Trichoderma viride, andZygorhynchus vuilleminiiwere grown on slide cultures supported above cultures of seven bacteria and one actinomycete. Except withEscherichia coliandNocardia corallina, heavy bacterial growth always inhibited growth and sporulation of the fungi, whereas lighter growth either inhibited, did not alter, or stimulated growth and (or) sporulation, depending on the fungus–bacterium combination. Differential absorption of the volatiles by KOH, KMnO4, charcoal, or soil indicated that different volatiles were produced, that some were inhibitory and others stimulatory, and that at least some of the volatiles were organic. Volatiles emitted by germinating seeds reduced spore formation only inG.cerealis,Penicillium vermiculatum, andZ.vuilleminii, but otherwise had no effect on growth, sporulation, or morphology of the above fungi nor onAspergillus flavipesorCunninghamella elegans.

ISSN:0008-4166    

DOI:10.1139/m74-015

出版商:NRC Research Press    

年代:1974

数据来源: NRC

摘要:

CBA/J mice were infected withTrypanosoma musculi. On the 10th day of infection, when the parasitemia had become stabilized and parasites consisted only of adult (non-dividing) trypomastigotes, non-adherent spleen cells from immune donors were injected intravenously, with or without simultaneous subcutaneous administration of immune serum. The immune spleen cells accelerated the termination of infection whilst immune serum transfer had no effect on the course of the parasitemia.

ISSN:0008-4166    

DOI:10.1139/m74-016

出版商:NRC Research Press    

年代:1974

数据来源: NRC