The pyrE Gene as a Bidirectional Selection Marker in Bifidobacterium Longum 105-A.

ABSTRACT: We constructed a deletion mutant of the pyrE gene in Bifidobacterium longum 105-A. A pyrE knockout cassette was cloned into pKKT427, a Bifidobacterium-Escherichia coli shuttle vector, and then introduced into B. longum 105-A by electroporation. The transformants were propagated and spread onto MRS plates containing 5-fluoroorotic acid (5-FOA) and uracil. 5-FOA-resistant mutants were obtained at a frequency of 4.7 × 10(-5) integrations per cell. To perform pyrE gene complementation, the pyrE gene was amplified by PCR and used to construct a complementation plasmid (pKKT427-pyrE (+)). B. longum 105-A ∆pyrE harboring this plasmid could not grow on MRS plates containing 5-FOA, uracil and spectinomycin. We also developed a chemically defined medium (bifidobacterial minimal medium; BMM) containi

SUBMITTER: Sakaguchi K 

PROVIDER: S-EPMC4034322 | biostudies-literature | 2013

REPOSITORIES: biostudies-literature