Characterization and genomic analysis of phage asccphi28, a phage of the family Podoviridae infecting Lactococcus lactis.

Bacteriophage asccphi28 infects dairy fermentation strains of Lactococcus lactis. This report describes characterization of asccphi28 and its full genome sequence. Phage asccphi28 has a prolate head, whiskers, and a short tail (C2 morphotype).

Construction of a combined physical and genetic map of the chromosome of Lactobacillus acidophilus ATCC 4356 and characterization of the rRNA operons.

The combination of PFGE and hybridization approaches was used to study the genome of Lactobacillus acidophilus neotype strain ATCC 4356. PFGE analysis of chromosomal DNA after digestion with each of the rare-cutting restriction enzymes I-CeuI, NotI, CspI, SmaI, ApaI and SgrAI allowed the size of the circular chromosome of L. acidophilus to be estimated at 2.

Novel expression system for large-scale production and purification of recombinant class IIa bacteriocins and its application to piscicolin 126.

Piscicolin 126 is a class IIa bacteriocin isolated from Carnobacterium piscicola JG126 that exhibits strong activity against Listeria monocytogenes. The gene encoding mature piscicolin 126 (m-pisA) was cloned into an Escherichia coli expression system and expressed as a thioredoxin-piscicolin 126 fusion protein that was purified by affinity chromatography. Purified recombinant piscicolin 126 was obtained after CNBr cleavage of the fusion protein followed by reversed-phase chromatography.

Transduction of concatemeric plasmids containing the cos site of Lactococcus lactis bacteriophage sk1.

Lactococcus lactis bacteriophage sk1 can transduce plasmids containing the phage cos site and surrounding DNA sequences at frequencies as high as 2x10(-3) transductants per PFU. Deletion analysis demonstrated that the presence of phage DNA spanning cos and putative R sites were the most important for efficient plasmid transduction. Inserts of 440 bp containing cos and the R sites were sufficient to induce transduction frequencies of 10(-4) transductants per PFU.

Pulsed-field gel electrophoretic analysis of the genome of Lactobacillus gasseri ATCC33323, and construction of a physical map.

Some species of Lactobacillus are of major industrial and health significance as fermenting agents in the manufacturing of food products, as food preservatives, as "probiotic" bacteria or as vaccine delivery vehicles. In spite of their importance, there is a paucity of published information on their genome organization and structure. In this study, a combination of pulsed field gel electrophoresis (PFGE) and hybridization approaches was used to investigate the genome of L.

A Simple and Rapid Method for Genetic Transformation of Lactic Streptococci by Electroporation.

An electroporation procedure for the plasmid-mediated genetic transformation of intact cells of Streptococcus cremoris and Streptococcus lactis was performed. Ten different strains were transformed. The method was simple and rapid and yielded transformant colonies in 14 to 24 h.