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. 2018 Jan 5;9(9):8548–8559. doi: 10.18632/oncotarget.24013

Figure 3. Expression of L-ASNase in ∆ppGpp Salmonella carrying pQSR-ASNase, pQSI-ASNase, or pQSRI-ASNase during growth in vitro.

Figure 3

(A) Plasmid constructs carrying ASNase under control of different combinations of QS elements, LuxR, and/or LuxI. (B) Salmonella carrying the indicated plasmids were grown in LB, and bacterial samples (pellets) were taken for analysis of L-ASNase expression by Western blotting. The last row shows L-ASNase secreted from Salmonella carrying pQSRI-ASNase into media (supernatant). (C) L-ASNase activities from Salmonella carrying the indicated plasmids. Asterisks (*) indicate significant differences vs. pQSI-mCherry (***P = 0.0005, ****P < 0.0001). (D) Salmonella were grown to stationary phase (9 hr) in LB (bacteria carrying pQSRI-ASNase) or in LB with or without 0.2% L-arabinose (bacteria carrying PBAD::ASNase). Equal amounts of bacterial cultures were harvested, separated into pellet and supernatant fractions, and analyzed for L-ASNase by Western blotting (upper panel) or an assay kit (supernatants only; lower panel). Asterisks (*) indicate significant differences vs. pBAD24 plasmid (Mock) (***P = 0.0004, ****P < 0.0001).