Question

2. Why is it useful to have mechanisms for direct cell to cell communication and for long distance communication with cells not near each other?

3. Why would bacterial cells need to communicate with each other? What is the advantage? Find an example bacteria that communicate and how do they communicate?

please answer both questions

Answer 1

Bacteria communicate with each other by means of chemical signals and also through ion channels. Communication that take place between adjacent cells through chemical signals is called quorum sensing. These chemical signals are also called autoinducers. Long distance communication between bacteria occurs through ions. Both these communication takes place in biofilms produced by bacteria

Purpose of quorum sensing :

Quorum sensing bacteria produce and release autoinducers which are hormone like substances. Its concentration increases with an increase in bacterial cell population. Adjacent bacteria can sense these chemical signals and alter the gene expression and their behaviour and thus help in synchronisation of activity of large group of cells. By this way, bacteria behaves like a multicellular organism.

Purpose of ion mediated communication :

In a biofilm, the bacterial cells at the edges get more nutrients and hence they grow well. But the cells in the interior are deprived of nutrients. So these cells send electrochemical signals through ion channels to the cells in the edge of the biofilm. These signals help in reducing the consumption of nutrients by the edge cells and thus cells in the interior also recieve adequate nutrients. This helps in survival of bacteria in biofilms against the threat by antibiotics. Even if the cells in the exterior are destroyed by antibiotics, the cells in the interior can survive

Proteus species, Vibrio cholerae, Pseudomonas aeruginosa communicate through quorum sensing