Bacillus subtilis:

Colony Dynamics


In January 2001 I began studying the dynamics of Bacillus subtilis colonies under the direction of Dr. Joceline Lega, University of Arizona Mathematics Department, and Dr. Neil Mendelson, University of Arizona Molecular and Cellular Biology Department.  In addition to reading papers that discuss the colony dynamics and develop models to simulate the phenomena, I have observed the cultures first hand and performed experiments to further my understanding of the dynamics.  I intend the papers and images on this web site to summarize my research.




Colony Dynamics

Formaldehyde Experiment

Growth Rate Experiment

Individual Cell Motion



Mechanisms and Rate of Bacterial Colony Growth


Film Clips

We are grateful to Chris Kaufmann, Network Administrator at the Multimedia Learning Lab, for processing these movies for web posting. Viewing these films requires a media player (right-click on the appropriate link to download).

Clip 1:   (MPEG movie file, 3.05 MB) Bacillus subtilis swimming freely on a 0.6% agar surface.  Note the vortices of bacteria.  

Clip 2:  (MPEG movie file, 3.17MB) Formaldehyde experiment, discussed in Colony Dynamics and in Formaldehyde Experiment


Index of Images

Click on thumbnails for larger image.  File size:  301KB each


Bacillus subtilis colony, strain M22, 1981.



Bacillus subtilis colony, strain M8. Grown on 0.6% agar. On the left is an unprocessed image.  The image on the right has been processed using Image-Pro Plus, for ease of viewing.



Another view of the same M8 colony.



This is one frame of a film sequence of a colony under the same conditions of the first film clip above.  Look for the cells that are aligned parallel to each other in the upper right hand quadrant.  The image on the left is a processed version, and the alignment is much clearer.


This material is based upon work supported by the National Science Foundation under Grant No DMS9977116.  

Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation.


Catherine Ott

University of Arizona

September 2001 - Rev. January 2002 & May 2002