Fig. 1.

Growth rate measurements of RNAP mutants in minimal and rich media. The growth rates of three RNAP mutants derived from E. coli adapted to growth in glycerol M9 minimal medium (del27, eBOP43, and eBOP42) and three RNAP mutants derived from rifampin-resistant E. coli were determined in triplicate in M9 minimal media with various carbon sources and in LB-rich medium. Average growth rates of mutants relative to the wild type are shown and error bars represent the SD of measurements. The glycerol-adaptive mutants grew significantly faster than wild-type in minimal media with all three tested carbon sources, but grew slower than wild-type in LB rich medium. Numerical results (absolute values) are listed in Table S1.