FIG 2.

In vitro functional analysis. Hydrolytic activity of the K2 depolymerase on extracted exopolysaccharides from NIPH 2061 (K2 capsule type) host at different ionic strengths (pH 6, 0 to 500 mM NaCl, 37°C) (A), pH values (5 to 9, 0 mM NaCl, 37°C) (B), and temperatures (pH 6, 0 mM NaCl, 37 to 80°C) (C). The results are expressed as relative activity compared with the best activity value obtained at pH 6.0, 37°C. Significance was determined by Student t test (*, P < 0.05). (D) Circular dichroism analysis of the K2 depolymerase. Melting curve was acquired by measuring ellipticity at 222 nm from 25 to 90°C. (E) A. baumannii phage vB_AbaP_B3 adsorption onto NIPH 2061 cells pretreated with K2 depolymerase. Results are expressed as residual PFU percentages compared with results from adsorption assays with NIPH 2061 cells pretreated with PBS. *, statistically different (P < 0.01).