Fig. 3. Distribution of growth-specific proteins (Growth-specific proteins were considered to be the proteins detected only at low (positive values) or high (negative values) growth rates) over COG categories. (A) Acetate plus benzoate- and (B) acetate-limited retentostats. Samples were taken at t0 , the beginning of retentostat cultivation, at t1 ,growth rates of 0.0043–0.0058 h−1 and 0.0036–0.0043 h−1 in acetate- and acetate plus benzoate-limited retentostats, respectively, at t2 , growth rates of 0.0018–0.0022 h−1 and 0.0028–0.0031 h−1 in acetate- and acetate plus benzoate-limited retentostats, respectively, and at t3 , growth rates of 0.0019–0.0020 h−1 in acetate plus benzoate-limited retentostats