Summary P seudomonas aeruginosa produces increased levels of alginate in response to oxygen‐deprived conditions. The regulatory pathway(s) that links oxygen limitation to increased synthesis of alginate has remained elusive. In the present study, using immunofluorescence microscopy, we show that anaerobiosis‐induced alginate production by planktonic PAO 1 requires the diguanylate cyclase ( DGC ) SadC , previously identified as...