FIG. 7.

Role of OsuR in growth and gene expression. Wt, wild type (638R); osuR, osuR mutant. A. Effect of osuR mutation on growth in SDM supplemented with starch or maltose. B. Effect of starch on the expression of osuA in wild-type and osuR mutant strains. Relative expression levels were determined during anaerobic growth in a xylose-containing basal medium supplemented with or without 0.5% starch. Results are expressed as n-fold induction relative to expression levels in basal xylose medium without starch. Strains were grown anaerobically to mid-log phase and then 0.5% starch was added to induce osuABCD expression. Total RNA was isolated 1 h after starch addition and expression of osuA was analyzed by real-time RT-PCR. Data are presented as the means from three independent experiments.