Mixed‐species biofilms, consisting of Klebsiella pneumoniae , Pseudomonas aeruginosa , Pseudomonas fluorescens and Stenotrophomonas maltophilia , were grown in glass flow cells under either laminar or turbulent flow. The biofilms grown in laminar flow consisted of roughly circular‐shaped microcolonies separated by water channels. In contrast, biofilm microcolonies grown in turbulent flow were elongated in the downstream direct...