Author(s)

Gastón L. Miño^1*, Magali Baabour², Ricardo Chertcoff², Gabriel Gutkind³, Eric Clément⁴, Harold Auradou⁵, Irene Ippolito²

¹Lab. de Microscopía Aplicada a Estudios Moleculares y Celulares (LAMAE), Fac. de Ingeniería, Univ. Nac. de Entre Ríos (FI-UNER) and Inst. de Investigación y Desarrollo en Bioingeniería y Bioinformática IBB-(UNER-CONICET), Oro Verde, Argentina.
²Universidad de Buenos Aires, Facultad de Ingeniería, Grupo de Medios Porosos, Buenos Aires, Argentina.
³Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Cátedra de Microbiología, Buenos Aires, Argentina.
⁴Physique et Mécanique des Milieux Hétérogénes (UMR 7636 ESPCI/CNRS/Univ. P.M. Curie/Univ. Paris-Diderot), Paris, France.
⁵Laboratoire FAST, Univ. Paris Sud, CNRS, Université Paris-Saclay, F-91405 Orsay, France.

This paper describes our findings regarding the accumulation of motile bacteria at the rear of a confined obstacle and the physical description of the mechanisms at play. We found that the modification of flow due to the presence of the obstacle produces vorticity that favor the diffusion of bacteria towards the downstream stagnation point. By testing different flow rates, we determined the range in which bacteria accumulate. More interestingly, we observe that hydrodynamic interaction between the bacteria and the top and bottom surface of the microfluidic chip maintain the bacteria in the region where the flow velocity is lower than their own velocity. In the case of non-motile bacteria, this effect is not observed because bacteria follow the streamlines as passive tracers do.

E coli , Motility, Filtration, Microfluidic, Bacterial Accumulation

Miño, G. , Baabour, M. , Chertcoff, R. , Gutkind, G. , Clément, E. , Auradou, H. and Ippolito, I. (2018) E coli Accumulation behind an Obstacle. Advances in Microbiology, 8, 451-464. doi: 10.4236/aim.2018.86030.