Some marine microorganisms are well known for their ability to degrade hydrocarbons. Obligate hydrocarbonoclastic bacteria (OHCB) can consume hydrocarbons as a sole source of carbon and energy, having a key role in the metabolism of natural alkanes present in the ocean. These bacteria can degrade considerable amounts of spilled oil, and thus they show great potential for bioremediation. Alcanivorax borkumensis SK2, which is a model microorganism to study OHCB, is an aerobic rod-shaped bacterium that can consume alkanes in the ocean by forming biofilms on liquids; bacteria start assembling in a specific order around the oil drop followed by the development of a biofilm that totally consumes the oil drop. This process depends on the oil–water interfacial property of each bacterial cell but it is currently not clear how A. borkumensis forms biofilms during oil degradation. Most of what we know about bacterial oil degradation comes from analysis of ocean samples and microcosm assays examining crude oil and sea water. In this study, Prasad et al. leverage microfluidic experiments combined with quantitative microscopy and theoretical modelling to show that A. borkumensis optimizes oil consumption via formation of tubular biofilm morphologies.