FIG. 2.

(Top) Assay of chitinolytic activity on a plate with SM agar supplemented with colloidal chitin (0.2% [wt/vol]) (left) and on a plate with SM agar supplemented with colloidal chitin (0.2 [wt/vol]) plus HHL (10 μM) (right): 1 and 3, growth of mutant CV026; 2 and 4, growth of E. agglomerans IC1270 strain (positive control). Plates were incubated at 28°C for 4 days. (Bottom) Assay of chitinolytic activity of mutant CV026 grown in liquid SM medium with colloidal chitin (0.2% [wt/vol]) (left) and in the same medium supplemented with HHL (10 μM) (right). The colloidal chitin was almost completely hydrolyzed in the HHL-supplemented medium, whereas particles of nonhydrolyzed chitin are clearly visible in the unsupplemented medium. Bacteria were grown on the medium indicated at 28°C for 72 h with agitation (200 rpm).