FIG 7.

The ExpA RsmA double mutant exhibits cellulase and pectolytic enzyme activities similar to those of the RsmA mutant. Bacteria were grown to stationary phase on liquid minimal medium supplemented with 0.4% PGA. Cells were subsequently pelleted, and the supernatant was diluted 2, 3, and 5 times. The different dilutions were pipetted onto LB plates containing polygalacturonic acid to test for pectolytic enzyme activity (A) or carboxymethylcellulose to test for cellulase activity (B) in 20-μl drops. In the assay, we used five replicate drops per dilution per strain. (C) The diameters of cleared circles on the plates were measured and compared between strains.