FIG. 5.

Uptake of exogenous ectoine (1 mM) from the medium into the cells of E. coli DH5α or noninduced E. coli(pASK-ectABC) under salt stress (final concentration, 4% NaCl). Intracellular ectoine was not found in the absence of exogenous ectoine source under salt stress. Without salt stress, only small intracellular amounts (ca. 0.1%) were detectable. The uptake rate of exogenous ectoine was 1.6 mg g⁻¹ (dry weight [dw]) min⁻¹. wt, wild type.