FIG. 2.

Growth yields of B. bronchiseptica strains. The bars indicate growth yields of B. bronchiseptica strains after 24 h of culture in iron-replete batch cultures (36 μM iron; iron-sufficient growth conditions that repress alcaligin production) and iron-depleted SS batch cultures, expressed as A₆₀₀ (means ± standard deviations; n = 3). In iron-depleted SS batch cultures, growth of all strains was limited by the presence of only trace amounts of iron in the system. Cultures were initiated at a cell density of 0.05 ODU₆₀₀l using washed cells from 24-h iron-replete SS seed cultures. Abbreviations for strains used are as follows: wt, B103N; alcS, BRM16; alcS/alcS_Bb⁺, BRM16 (pRK/alcS_Bb); alcS/alcS_Bp⁺, BRM16 (pRK/alcS_Bp)