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. 2015 Feb 11;5:8398. doi: 10.1038/srep08398

Figure 5. Change in viscosity of DNA solution as a function of pyocyanin, ascorbic acid or glutathione concentration and viscosity of P. aeruginosa PA14 biofilm supernatants.

Figure 5

Increase in viscosity of a DNA solution with increasing pyocyanin concentration (a). P. aeruginosa PA14 wild-type biofilm supernatants show significant increases in viscosity compared with a ΔphzA-G mutant (phenazine-deficient) or fresh LB medium (a). The absorbance of biofilm supernatants at 691 nm (pyocyanin absorbance maxima) for fresh LB, wild-type and ΔphzA-G after 24 h incubation illustrates pyocyanin production by the wild-type (a). Pyocyanin in the presence of ascorbic acid (AA) or glutathione (GSH) at 250 and 500 μM significantly decreases DNA viscosity. Note that in the presence of 500 μM ascorbic acid or glutathione, the viscosity of the DNA-pyocyanin mixture and DNA solution by itself is lower than the original viscosity of DNA (~2.1 mPa s) at 1.7 and 1.6 mPa s respectively (b). Error bars represent standard deviation from the mean (n = 4). Asterisk, hash and plus symbols indicate statistically significant (P < 0.05) differences in comparison to pure LB and ΔphzA-G and pure DNA and absorbance, respectively (a). Asterisk, hash and plus symbols indicate that the changes are statistically significant (P < 0.05) in comparison to pure DNA, DNA-pyocyanin mixtures and pure DNA, respectively (b).