Evaluation of a new millifluidic device for the consistent determination of oil droplet biodegradation kinetics

Natural seeps and accidental releases of crude oil in the sea result in swarms of droplets that are carried away by underwater sea currents. The droplets may be created either at the sea surface during the breakup of an oil slick by sea waves, or at the seafloor during the extrusion of crude oil from natural cracks or broken wellheads. A high concentration of oil droplets in seawater disturbs the established ecosystem dynamics and poses a significant risk of toxic effects to fish and other marine animals. The fate of underwater droplet swarms is determined by natural attenuation processes, mainly dissolution into the seawater and biodegradation by oil-eating microbes. Using microfabrication techniques (photolithography and 3D printing), we have developed a new millifluidic device that enables the generation of oil droplet populations with desired size and, subsequently, the entrapment, long-term incubation and microscopic imaging of the droplets while they undergo microbial degradation. Here, we will present experimental results on the biodegradation of hexadecane droplets by Marinobacter sp. microbes in synthetic saltwater. Acknowledgement: EU Horizon 2020 MSCA Grant 741799 - "OILY MICROCOSM"