Figure 2.

ChiA2 is essential for chitin-induced natural transformation (a) WT strain incubated with increasing concentration of extracellular DNA for natural transformation. (b) WT and isogenic mutant strains ΔchiA, ΔchiA2 and ΔchiAΔchiA2 were naturally transformed on shrimp chitin flakes with 12.5 μg/mL extracellular DNA. Average of at least three independent experiments were represented. * Statistically significant difference between lowest and other concentrations of donor gDNA (p < 0.05); ** Statistically significant difference between the transformation frequency of WT and mutant strains (p < 0.05).