摘要
The large plasmids of strain 7653R were digested with restriction enzyme EcoRI. Their DNA fragments were cloned into the expression vector pMP220 to construct a lacZ fusion pool, which were transferred into the recipient strain 7653R Tri-transconjugants were selected onto plates containing X-gal and seed extract Five blue colonies were assayed of their β-galactosidase activity after incubation with or without seed extract. A positive induced strain HN18 was obtained. Hybridization of nodDABC probe on the recombinant plasmid pHN18 showed a 1.7kb positive band.The evidence makes a deduction that the pHN18 containes a promoter of nod operon.
The large plasmids of strain 7653R were digested with restriction enzyme EcoRI. Their DNA fragments were cloned into the expression vector pMP220 to construct a lacZ fusion pool, which were transferred into the recipient strain 7653R Tri-transconjugants were selected onto plates containing X-gal and seed extract Five blue colonies were assayed of their β-galactosidase activity after incubation with or without seed extract. A positive induced strain HN18 was obtained. Hybridization of nodDABC probe on the recombinant plasmid pHN18 showed a 1.7kb positive band.The evidence makes a deduction that the pHN18 containes a promoter of nod operon.
出处
《微生物学报》
CAS
CSCD
北大核心
1998年第3期225-228,共4页
Acta Microbiologica Sinica
基金
国家攀登计划
国家自然科学基金
