RESUMO
Formation of genetic recombinants after conjugation and protoplast fusion in Saccharopolyspora erythraea, an organism producing erythromycin, was studied comparatively. After the protoplast fusion the frequency of all the classes of the haploid recombinants increased 10 to 460 times by comparison with the conjugation. The protoplast fusion was characterized by higher diversity of the recombinant classes, up to 45.5 per cent of the recombinants being formed at the account of multiple crossing overs. It was shown that unlike conjugation of the S. erythraea strains the protoplast fusion had no gradient of inheritance of the parent genetic markers by the recombinants. The results indicated that in S. erythraea protoplast fusion the recombination involved more genes of the parent strains. This makes promising the procedure for genetic analysis and design of erythromycin-producing strains.
Assuntos
Eritromicina/biossíntese , Protoplastos/fisiologia , Recombinação Genética , Saccharopolyspora/genética , Conjugação Genética , Troca Genética , Marcadores Genéticos , Genótipo , Haploidia , Saccharopolyspora/metabolismoRESUMO
Erythromycin-producing strains of S. erythraeus were characterized with respect to formation of spontaneous and induced rifampicin-resistant mutants. It was shown that the frequency of spontaneous rifampicin-resistant mutants formed by various strains amounted to 0.9.10(-8) = 9.1.10(-7). In some events the exposure to nitrosoguanidine increased the frequency of such mutants by 2 orders of magnitude. The rifampicin-resistant mutants differed in antibiotic resistance. It was found that a significant part of the rifampicin-resistant mutants became sensitive to heating (19.1 per cent) and lost the ability to form aeromycelium (21.8 per cent).
Assuntos
Mutação/genética , Rifampina/farmacologia , Streptomyces/genética , Meios de Cultura , Resistência Microbiana a Medicamentos/genética , Técnicas In Vitro , Testes de Sensibilidade Microbiana/métodos , Mutação/efeitos dos fármacos , Streptomyces/efeitos dos fármacos , Streptomyces/isolamento & purificaçãoAssuntos
Carbono-Carbono Ligases , Eritromicina/biossíntese , Genes Bacterianos/genética , Microbiologia Industrial/métodos , Mutação/genética , Streptomyces/metabolismo , Tilosina/biossíntese , Acil Coenzima A/metabolismo , Meios de Cultura , Técnicas In Vitro , Ligases/metabolismo , Streptomyces/genéticaAssuntos
Isoanticorpos/isolamento & purificação , Lectinas/imunologia , Sistema do Grupo Sanguíneo MNSs/imunologia , Sistema ABO de Grupos Sanguíneos/imunologia , Tipagem e Reações Cruzadas Sanguíneas/métodos , Eritrócitos/imunologia , Testes de Hemaglutinação/métodos , Humanos , Isoanticorpos/imunologiaRESUMO
The crystalline preparation of antithyroid phytoprecipitin has been resolved by chromatography on Whatman CM-32 cellulose on a preparative scale into two components, designed respectively A and B. Each component was further resolved into consisting polypeptide chains alpha (mol. weight 7.000) and beta (mol. weight 17.000) by gel filtration on sephadex G-50 in 1 M acetic acid 6 M urea. Homologous chains were comparatively studied by electrophoresis in acrylamide gel, amino acid analysis and peptide mapping technique. Electrophoresis in acrylamide gel with 6 M urea according to Takayama [8] revealed the identical mobility of beta chains in both components A and B, while alpha chains differed. alphaA chain was more basic, than alphaB, i.e. it had greater positive sharge. The amino acid analysis and peptide mapping showed that alphaA chain had one residue of lysine more than alphaB chain. The comparison of beta chains by peptid mapping confirmed their complete identity.
