Influence of NO and NO synthase (NOS) on colony morphology and fruiting body formation of B. subtilis 3610. (A-E) Colonies were grown for 4 d on MSgg agar and images were captured with a digital camera. (F-K) Colonies were grown for 3 d on MSgg agar and images were captured with a CCD camera mounted on a microscope. NO scavenger (c-PTIO), NOS inhibitor (L-NAME) and NO donor (Noc-18) were added to biofilm incubations of B. subtilis wild-type. Scale bars are 1 cm (A-E) and 200 μm (F-K).