Mutants of Corynebacterium diphtheriae PW8 that produce toxin in medium with excess iron.
نویسندگان
چکیده
Two mutants that produce toxin in medium with excess iron were isolated from the PW8 strain of Corynebacterium diphtheriae. These mutants produced as much toxin in medium containing excess iron (3 mug of Fe2+ per ml) as did the parent PW8 strain in iron-depleted medium, and they will be very useful for easy production of toxin.
منابع مشابه
Isolation of a cured strain from Corynebacterium diphtheriae PW8.
A nonlysogenic, non-toxinogenic strain was isolated from the PW8 strain of C. diphtheriae by two-step ultraviolet induction. This strain was lysed by phages derived from the PW8 strain but not by beta phages from the C7(beta) strain. When this cured strain was lysogenized with phages from the PW8 strain, toxin production by the resulting lysogens was about a half or a quarter of that of the par...
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Mutants of Corynebacterium diphtheriae C7(beta) that are resistant to the inhibitory effects of iron on toxinogenesis were identified by their ability to form colonies surrounded by toxin-antitoxin halos on agar medium containing both antitoxin and a high concentration of iron. Chromosomal mutations were essential for the altered phenotypes of four independently isolated mutant strains. During ...
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The construction of a hexahistidine-tagged version of the B fragment of diphtheria toxin (DTB) represents an important step in the study of the biological properties of DTB because it will permit the production of pure recombinant DTB (rDTB) in less time and with higher yields than currently available. In the present study, the genomic DNA of the Corynebacterium diphtheriae Park Williams 8 (PW8...
متن کاملPark-Williams number 8 strain of Corynebacterium diphtheriae.
Five clones of the Park-Williams number 8 strain of Corynebacterium diphtheriae, previously maintained in separate laboratories, were examined for their colonial and biochemical properties, for the restriction and modification system which operates to obscure their lysogeny, and for their capacity to produce large amounts of toxin under ordinary laboratory conditions. The phenotypes of their ph...
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The Corynebacterium diphtheriae irp1 gene is negatively regulated by DtxR and iron. The nucleotide sequence of irp1 revealed that it has homology with genes involved in iron acquisition. Expression of the irp1 gene showed that it encodes a lipoprotein (IRP1) with a predicted size of 38 kDa. Northern blot experiments indicated that transcription from the irp1 promoter is repressed in high-iron m...
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ورودعنوان ژورنال:
- Applied and environmental microbiology
دوره 42 6 شماره
صفحات -
تاریخ انتشار 1981