Figure 4

Optimization of ectoine production. The initial reaction mixture containing 100 mM sodium phosphate buffer (pH 7.0), 50 mM sodium aspartate, 50 mM KCl, 100 mM glycerol, and recombinant E. coli cells of 5 OD/mL was incubated at 30°C for 24 h. (A) Effects of sodium aspartate concentration on the production of ectoine. (B) Effects of KCl concentration on the production of ectoine (the concentration of sodium aspartate was 100 mM). (C) Effects of temperature on the production of ectoine (the concentrations of sodium aspartate and KCl were 100 mM). (D) Effects of pH on the production of ectoine (the concentrations of sodium aspartate and KCl were 100 mM). Error bars respresent standard deviations from triplicate biological replicates.