Investigation of living bacteria using optical fiber tweezers

Over the last years, optical tweezers became an essential non-invasive observation, characterization and manipulation tool in microbiology, chemistry and solid state physics. In particular, optical tweezers permit to get deeper insight into biological species such as cells, viruses, or bacteria.
In this context, we have developed an original optical tweezers approach based on nanostructured optical fibers. In this technique, the trapping light beam is emitted by an optical fiber close to the trapped species, thus limiting optical aberrations and other problems when working in crowded media. Recently we applied this fibered optical tweezers for investigating P. aeruginosa bacteria. This species is of particular intersest because it harbours an efficient unique flagellum and diverse extracellular appendages including Type 4 pili also involed in motility. We could demonstrate efficient optical trapping and observed interesting features of bacteria swimming behavior. The main object of this internship is to go further into the characterization of trapped and swimming bacteria, e.g. to observe the division of trapped bacteria, or to investigate the relation between the bacteria speed and its flagellum rotation frequency.

contact: jochen.fickATneel.cnrs.fr

More information : http://neel.cnrs.fr