ABSTRACT
One of the advantages of using continuous culture is that the cell's environment can be rigidly controlled. A better example of a genetic selection occurring in continuous culture is that of strains producing hyper levels of ß-galactosidase. Continuous culture has also been used to select for dispensible enzymes. Continuous cultures have been used extensively to study the incidence of antibiotic resistance in bacteria. Resistance to bacteriophage has also been a focal point for microbiologists interested in continuous culture. The effectiveness of mutagenic agents or treatments can be ascertained in continuous culture easily. Ordinarily mutation rates are expressed as mutants produced per parent cell per generation. Metabolic economy thus may select not only for point mutants that possess lower levels of the nonessential enzymes, but for deletions that no longer synthesize DNA, mRNA, or even protein corresponding to the deleted gene.
