The behavior in Saccharomyces cerevisiae of plasmid pYTE1, which contains yeast tyrosine-inserting ochre suppressor SUP4.o, a 4-kilobase EcoRI fragment of yeast 2muDNA, and the bacterial plasmid pBR322, has been studied. Selection of yeast transformants was by suppression of multiple ochre mutations. About 10(3) to 10(4) transformants per microgram of pYTE1 dfeoxyribonucleic acid were obtained....

Acidophilic heterotrophic strain GS19h of the genus Acidocella exhibited extremely high resistance to CdSO4 and ZnSO4, with a MIC of 1 M for each. The respective MICs for an Acidocella aminolytica strain were 400 and 600 mM. The MICs of NiSO4 for the above strains were 200 and 175 mM, respectively. These strains were also resistant to CuSO4, the MICs being 20 and 40 mM, respectively. An Acidoce...

A recombinant plasmid, designated pUC1002, was constructed by ligation of a HindIII restriction endonuclease fragment of Escherichia coli chromosomal DNA to vector plasmid pMB9. Strains carrying this plasmid were selected by transformation of an E. coli strain bearing the xyl-7 mutation to a xylose-positive (Xyl+) phenotype. Strains containing pUC1002 produced coordinately elevated levels of D-...

We examined bovine papillomavirus type 1 (BPV-1) DNAs mutated in the E2 open reading frame (ORF) to determine their ability (i) to transform C127 cells and (ii) to remain extrachromosomal in transfected cells. Results obtained with deletion mutants and insertion mutants containing a linker with translational termination codons in all possible reading frames indicated that an E2 ORF gene product...

The Hanahan protocol is widely used to transform bacterial cells with a plasmid of interest. However, little is known about the mechanism by which bacterial cells, particularly Escherichia coli, take up these plasmids. It was hypothesized that the PitA phosphate uptake system, which has been shown to transport divalent metal cations including Ca, may be involved in the Ca-mediated plasmid uptak...

The present study was aimed to detect the plasmid profile, the role of plasmid associated multiple antibiotic resistance of Vibrios isolated from coastal waters of Kerala. The isolated plasmids from antibiotic resistant Vibrios were tested for the presence of integrons using polymerase chain reaction (PCR) to elucidate the presence of plasmid borne integron, a key element in horizontal gene tra...

INTRODUCTION .......................................................... 409 PURIFUICATION OF PLASMID DEOXYRIBONUCLEIC ACID FROM STREPTCOCCI ......................................................... 412 CONJUGATION AND PLASMID TRANSFER ......... ........................ 413 SEX PHEROMONES IN STREPTOCOCCUS FAECALIS ....... ................ 415 RESISTANCE TRANSFER IN THE ABSENCE OF PLASMID DEOXYRI...

A broad-host-range cloning vector, pUI81, was constructed in vitro from plasmids RSF1010 and pSL25 (a pBR322 derivative) and used to assay for transformation in Rhodopseudomonas sphaeroides. Washing cells with 500 mM Tris was an effective means of inducing competence for DNA uptake. Transformation frequencies as high as 10(-5) (transformants per viable cell) have been achieved by incubating Tri...

A protocol was developed for the introduction of foreign plasmid DNA into various Bifidobacterium strains. The method, which is applicable to all Bifidobacterium species tested so far, is based on electroporation of bacteria made competent by preincubation in electroporation buffer for several hours at 4 degrees C. Transformation of Bifidobacterium could be achieved with a plasmid vector origin...

The plasmid pC5, which encodes biogenesis of lycopene in Mycobacterium aurum A(+), was partially digested by restriction endonucleases and generated fragments were cloned. After transformation of Escherichia coli (colorless bacteria) with the plasmids so constructed, seven orange clones were detected and found to carry the same recombinant plasmid (pC51). E. coli cells containing this plasmid s...