Bacterial turbulence

Dramatic patterns of synchronized motion are often observed in large flocks of birds or shoals of fish, and have fascinated scientists for a long time. Such displays throw up two basic questions. Firstly, how do flocks manage to co-ordinate themselves over very large distances with no apparent means of long-range communication? And secondly, do the self-organized patterns serve some purpose at all for the individuals involved, and for the overall flock? Although there have been several recent breakthroughs in understanding such behaviour, there are at present no firm answers to these questions, mostly due to the lack of controlled experiments on large mobile populations.

Complex patterns - reminiscent of turbulent flows in fluids - are also observed in colonies of mobile bacterial cells moving on surfaces, or in fluid environments. We can now perform controlled experiments on bacterial systems to gain insight into the larger problem of self-organization in mobile populations. Moreover, understanding the physical mechanisms behind the ability of pathogens like Pseudomonas aeruginosa to rapidly colonize surfaces may prove useful in controlling biofilm formation, often implicated in diseases like cystic fibrosis.

This talk will broadly review how biophysics, fluid mechanics and high-performance computing are being used to understand this phenomenon of "bacterial turbulence".

Prabhakar's presentation 4.7MB

Pseudomonas aeruginosa turbulance - slide 7 .mov 10.2MB

Bacteria boid models - slide 16 .mov 11.2MB