37 C, aerobic or micro-aerobic 48h incubation

hi, you can incorporate colloidal chitin into nutrient agar and clearing zones will occur around the culture. If not, after you've grown the culture in chitin broth harvest supernatant and inoculate colloidal chitin agar and incubate overnight. You should see clearing zones.  

Dear Dirk and Justin thanks a lot.

I reduced the agar concentration, at least I can grow isolates on the medium but still no clear zones in different temperatures even after 2 week incubation.

in the case of incubation the sup with colloidal chitin agar, I should try it. Good idea.

Thanks all