Abstract: Quiescence is induced in cells using indole compounds. Expression continues from extra-chromosomal vectors within the cells during quiescence, while chromosomal expression is suppressed. The cells may be used as factories for the production of large amounts of polypeptides of interest, particularly polypeptides which normally have an adverse effect on cell viability or growth. Expression from an extra-chromosomal vector of interest may be monitored, in view of the reduced background expression from the chromosome. Vector copy number may be amplified. Cell cycles may be synchronized.

Abstract: Quiescence is induced in cells using indole compounds. Expression continues from extra-chromosomal vectors within the cells during quiescence, while chromosomal expression is suppressed. The cells may be used as factories for the production of large amounts of polypeptides of interest, particularly polypeptides which normally have an adverse effect on cell viability or growth. Expression from an extra-chromosomal vector of interest may be monitored, in view of the reduced background expression from the chromosome. Vector copy number may be amplified. Cell cycles may be synchronized.

Abstract: Disclosed are methods for generating mycolic acid bacterial biosensors for particular analytes (especially industrial pollutants) by the use of innovative methods for isolating DNA encoding an inducible promoter which is induced in response to the specific analyte (and/or associated operon proteins), the methods generally comprising the steps of: (a) culturing a source of mycolic acid bacteria in a selective medium containing said specific analyte and being selective for oligotriphic bacteria; (b) identifying mycolic acid bacteria capable of subsisting on said medium, especially those which do not display catabolic repression; (c) extracting DNA from said mycolic acid bacteria; (d) incorporating said DNA into vectors, such as various shuttle vectors; (e) cloning said vector into a suitable host cell (which may be E.

Abstract: The invention features a bacterial cell containing an extra-chromosomal vector that includes an inducible rcd gene, wherein the cell, when placed in broth culture, enters quiescence on expression of the rod gene.