Assessment of regulation of β-galactosidase expression from the conditional expression vectors.

<p><i>lacZ</i>/KD/SO (top panel) and <i>lacZ</i>/KD/DO (bottom panel) were grown at 37°C in the absence and the presence of different concentrations of IPTG and 40 μg/ml of X-gal. Wild-type <i>M</i>. <i>smegmatis</i> mc²155 (WT) was used as control which received 1000 μM IPTG and 40 μg/ml X-gal. The numbers indicate the μM IPTG concentrations used in the respective tubes.