  Shewanella oneidensis MR-1 are facultative aerobic electroactive bacteria,
with an appealing potential for sustainable energy production and
bioremediation. They gather around air sources, forming aerotactic bands and
biofilms. Though accumulation is crucial to technological exploitation, their
collective behaviour remains poorly reported. Here we establish a comprehensive
framework for the study of aerotaxis, unveiling a novel hybrid locomotion
pattern. Despite having only one flagellum, MR-1 combine motility features of
mono- and multiflagellate bacteria, alternating longitudinal fast and sideways
slow swimming. The adaptive tuning of the resulting bimodal velocity
distributions fulfils different biological functions, such as aerotaxis and
confinement. Overall, we reveal the mechanisms underlying the aerotactic
collective behaviour of MR-1, in the process leading from accumulation to
biofilm formation
