Figure 4
Expression of recombinant SyNOS increases the maximum OD of E. coli culture growing in either sufficient or deficient N conditions. (a) E. coli cultures expressing recombinant SyNOS containing a myc-tag or the empty vector pET24a (EV) were grown in LB media and induced with 0.1 mM IPTG. Growth was followed by measuring OD 600. Error bars represent ± SE (n = 4). (b) Dilutions (10−3, 10−4 and 10−5) of E. coli cultures expressing SyNOS or EV and induced with IPTG 0.1 mM for 4 h were plated in LB agar and grown for 18 h at 37 °C. The number of colony-forming units (CFU) per ml from E. coli was quantified. Error bars represent ± SE (n = 3). The asterisk indicates a significant difference compared to EV (t-test, p < 0.05). (c) Curves of E. coli cultures growing in media with sufficient or deficient N conditions. Bacteria expressing SyNOS or EV (OD 600 ~ 1) grown in LB were diluted (1/100) in minimum media containing 0.2% (w/v) glucose with 0.3% or 0.018% (w/v) NH4Cl (N source). Culture growth was quantified by OD 600. Error bars represent ± SE (n = 3).
