Dennis H. Steinberg

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The plasmid pER341 (2798 bp) of Streptococcus thermophilus ST134 was sequenced and its open reading frame (ORF) regions were characterized. Analysis of nucleotide sequences showed the putative translation product of ORF1 (rep) sharing a high level of homology with replication proteins of several small plasmids present in lactic acid bacteria and(More)
A rapid and convenient electroporation procedure was developed for the genetic transformation of intact cells of Streptococcus thermophilus with various species of plasmid DNA. Transformation frequency was influenced by the capacitance and voltage selected for electric pulsing, the pH and composition of the electroporation medium and the molecular mass of(More)
In a survey of 35 strains ofStreptococcus thermophilus, 13 strains were found to harbor plasmid DNA. Most of these strains contained plasmid species varying in size from 2.2 to 7.15 kilobases. Only three strains had more than one plasmid species. Each of the nine distinct types of plasmid DNAs identified had two or more unique recognition sites for(More)
A 138-bp EcoO109/HinfI fragment of Streptococcus thermophilus plasmid pER341 (2798 bp) including the promoter sequence of the heat stress protein gene hsp16.4 was tested in vector constructs for ability to activate the promoterless green fluorescent protein gene (gfp) from a jelly fish in Escherichia coli, S. thermophilus, and lactococci. ST(Phsp) promoted(More)
The presence of heat stress protein genes (hsp) was tested by Southern hybridization analysis in total DNA extracts from species of the genus Streptococcus (47 strains), Lactobacillus (34 strains), Lactococcus (24 strains), and Leuconostoc (5 strains). The biotinylated hsp16.4 probe prepared from an ORF2 fragment of pER341 (2.8 kb) tested positively with(More)
The direct selection of bacteriocin-producing lactic fermentation bacteria was possible by plating diluted cultures of Pediococcus acidilactici on mixed agarose agar layers with the amount of each component incrementally adjusted to 1.2% (w/v). Between 0.5 and 1% agarose, the increased flexibility of the solidified support layer allowed its removal from(More)
The recombinant plasmid pNCO937 (8.1 kbp) containing a Streptomyces sp. cholesterol oxidase gene was introduced into Streptococcus thermophilus by electrotransformation. Transformation frequency was 7.2 x 10(5) colony forming units/micrograms of DNA. The presence of the cholesterol oxidase gene in S. thermophilus was confirmed with Southern blot analysis(More)
The cholesterol oxidase gene (choA) of a streptomycete was used as a model for studying heterologous gene expression in Streptococcus thermophilus, an essential bacterium in dairy food fermentations. The vectors pER82 and pER82P were developed from the 2.2-kb indigenous plasmid (pER8) of S. thermophilus ST108, and sP1, a 51-bp synthetic promoter patterned(More)
The chimeric plasmid pBN183 was first constructed in Escherichia coli by ligating the BamHI-digested E. coli plasmid pBR322 and a Bg/II-linearized streptococcal plasmid, pNZ18. The pBN183 transformed E. coli to ApR at a frequency of (8.2 +/- 1.2) x 10(5) colony forming units (CFU)/microgram DNA. Electrotransformation of Streptococcus thermophilus with(More)
The 2.3-kb erythromycin resistance (EmR) plasmid pPV141 of Staphylococcus chromogenes 3688 was isolated and characterized. Nucleotide sequence analysis identified ORF1 and ORF2 separated by a 445-bp spacing, encoding a 158-residue replication protein (Rep141) and a 244-residue erythromycin resistance protein (Erm, rRNA adenine N-6-methyltransferase),(More)