Figure 1.

VPA0055 or ChiA2 is the major ChiS-dependent chitinase required for the growth of V. parahaemolyticus in the presence of chitin. (a) The relative expression of four chitinase genes at mRNA level was checked for the ΔchiS mutant compared to the WT strain. recA was used as an internal control. Each bar indicates the mean ± SE of three independent experiments. Asterisks represents p < 0.05, where a fold change in mRNA expression of the ΔchiS mutant was significantly affected. (b) Growth curve of the indicated isogenic mutants and WT in DASW with chitin as sole carbon source. Each point represents the mean ± SE of three independent experiments. (c) Chitinase plate assay. Wild type and indicated isogenic mutants of V. parahaemolyticus were assayed for chitinase activity using DASW plate containing 2% colloidal chitin.