One species of bacteria have developed a unique mechanism for coping with overpopulation. They change their shape. Researchers at the University of Texas, Austin, describe a newly discovered mechanism that the bacterium Paenibacillus dendritiformis uses to survive overcrowding.
P. dendritiformis is typically a rod-shaped bacterium. As it grows it produces a toxic protein, called sibling lethal factor (Slf) which kills cells of encroaching sibling colonies. However, the researchers found that sublethal levels of Slf induce some of the rods to switch Slf-resistant cocci-shaped bacteria.
When crowding is reduced and nutrients are no longer limiting, the bacteria produce another signal that induces the cocci to switch back to rods, allowing the population to spread.
The research was published in American Society for Microbiologys journal, mBio.