DEEP WORK

PLASMID REPLICATIONCopy Number Control and Its Role in Segregational StabilityMaintaining an upper limit to plasmid copy number may be necessary to ensure the viability of the host. In addition, to prevent plasmid loss, copy number controls must also respond rapidly in a cell inheriting few copies. This is pa1rticularlty important in the absence of a separate partitioning locus (par). No evidenc..

INTRODUCTIONNumerous plasmids of gram-positive bacteria have been identified, analyzed for their properties, and used as cloning vectors. The range of species from which plasmids have been isolated is broad, yet the properties of most of these plasmids indicate that a common gene pool had been used in their formation (36, 76). The regions of homology may involve essential or nonessential genes, ..

1. INTRODUCTIONLactobacillus, one of the lactic acid bacteria, is a natural inhabitant in the gastrointestinal tract of man and animals (Conway et al., 1987) and an important bacterium in the food industries of fermented dairy, meat, and vegetable, and also in animal feed (Chassy, 1985; Lee, 1996). In addition, it is believed to offer some benefits as probiotics in human health, such as detoxify..