منابع مشابه
Transformability of streptomycin-resistant group H streptococci.
Several resistant mutants of a transformable group H streptococcus, strain Challis, were isolated from media containing high concentrations of streptomycin. Mutants SR5a and SR5 exhibited high and low transformability, respectively, when exposed to deoxyribonucleic acid (DNA) from a novobiocin-resistant Challis strain. With similar exposure, mutant SR30 exhibited loss of transformability. The m...
متن کاملPreparation of protoplasts of group H streptococci (Streptococcus sanguis).
Stable protoplasts of several strains of group H streptococci (Streptococcus sanguis) can be prepared by use of group C streptococcal phage-associated lysin in the presence of 30% raffinose. Sucrose cannot be substituted for raffinose. Protoplast formation did not require the addition of Mg2+; however, this cation enhanced their stability. Some other strains, also presumptive group H streptococ...
متن کاملInhibition of transformation in group H streptococci by lysogeny.
Group H streptococcal strains Challis and WE4 were lysogenized with a bacteriophage isolated from strain Channon, after which their capacity for transformation to streptomycin and rifampin resistance was reduced by three orders of magnitude. The probable reason is the inability of the lysogenized strains to bind deoxyribonucleic acid irreversibly, even though they exhibit earlier stages of comp...
متن کاملGrowth and development of competence in the group H streptococci.
The growth and development of competence by group H streptococci, strain Challis, were compared in synthetic, semisynthetic, and complex media with respect to the cultural conditions required, time of onset and persistence of competence and transformation efficiency. Provided that cultural conditions were strictly controlled in the synthetic system, transformation frequencies of 1% or above wer...
متن کاملTransformation in group H streptococci: blackburn strain transformable mutants.
Transformable mutants of the nontransformable Blackburn strain group H streptococci have been isolated. In contrast with the wild strain, the cell surface extracts of these mutants contain the factor inactivating deoxyribonucleic acid in vitro.
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ژورنال
عنوان ژورنال: Journal of Bacteriology
سال: 1973
ISSN: 0021-9193,1098-5530
DOI: 10.1128/jb.113.3.1505-1506.1973