FIG. 6.

Catabolite modulation of pla transcription. (A) Selected strains of Y. pestis carrying pGY778 expressing Ppla-lacZ were cultivated in buffered L medium without or with glucose or glycerol. The strains examined were GY5531 (wild type) (WT), GY5533 (crp), GY5538 (crp, vector control), GY5539 (crp, vector + crp), GY5564 (cyaA), GY5595 (cyaA, vector control), and GY5597 (cyaA, vector + cyaA). The results are averages ± standard deviations from at least two independent experiments performed in duplicate. The mean value for each sample was compared to the control value (wild type, no supplement) by the two-tailed t test. Values that were considered significantly different (P < 0.05) are indicated by an asterisk.