Dynamic guiding of bacteria in lyotropic chromonic liquid crystal using magnetic field

Abstract

This article demonstrates a new approach enabling the active control of swimming trajectories of flagellated bacteria in space and time. Bacteria were mixed with water solutions of disodium cromoglycate (DSCG), a lyotropic chromonic liquid crystal (LCLC) that mimics the anisotropic properties of many biological environments. It has been well established that the bacteria then swim in the direction of the self-aligned molecular aggregates of DSCG. It is also known that this host material possesses a diamagnetic anisotropy enabling the control of the local orientation of these aggregates with magnetic fields (MF). This double coupling (bacteria-LCLC & LCLC-MF) allows the efficient real-time control of the orientation of bacterial trajectories. Such control over the motility of microorganisms opens numerous avenues for their manipulation and study, for example, in a lab-on-a-chip device.

Keywords:

• Flagellated bacteria
• E. coli
• DSCG
• living liquid crystal
• active control & magnetic field

Acknowledgments

M.A. Boulé and T. Galstian acknowledges the financial support of the Natural Sciences and Engineering Research Council of Canada (grant 05888) and of the Canada Research Chair in LCs and Behavioral Biophotonics (grant 230212). T. Galstian also thanks Manning Innovation and CAP-INO Medal Foundations for their support.

Notes

1 Optical Adhesive 65, Norland, Cranbury, NJ

2 Duke Scientific Corporation

3 Nissan Chemical B79032-50, Houston, TX

4 Indigo Instruments, Waterloo, Ontario