Alcanivorax borkumensis Biofilms Enhance Oil Degradation By Interfacial Tubulation

Alcanivorax borkumensis are prominent actors in oil spill bioremediation; however, the interfacial dynamics of their biofilms and its role in oil degradation remain unclear. Longitudinal tracking of biofilm-covered oil microdroplets using microfluidics reveals a spontaneous morphological transition from a thick biofilm phenotype to a thin dendritic phenotype optimized for high oil consumption rates. We show experimentally that biofilm dendrites emerge from aster-like nematic defects in the thin biofilms. We develop a theoretical model that elucidates the transition between phenotypes, linking tubulation to decreased interfacial tension and increased cell hydrophobicity, which we verify experimentally. We demonstrate positional control over the nematic defects on the droplets using microfluidics, causing the biofilm to dimple the droplets. Our results reveal how A. borkumensis biofilms utilize topological defects to increase oil access to achieve superior oil consumption rates, which may be a general strategy in oil-consuming bacteria. ONE SENTENCE SUMMARYA. borkumensis adapt their interfacial properties over time to evolve their biofilm phenotype and increase their oil consumption