The mechanism of aggregate formation by Selenomonas ruminantium

The mechanism of granule formation by Selenomonas ruminantium was investigated. A basic protein has been isolated from the lysate of S. ruminantium which triggers cluster formation of suspended cells. Evidence is presented that these basic proteins were of ribosomal origin. Adding lysate to suspended cells, followed by lowering of the pH from 5.8 to 4.5 also induced clustering. Within the clusters, lysis and a low pH are induced due to diffusion limitations. As a consequence dividing cells are entrapped within the clusters, resulting in growth.