Question

Define the term “Biofilm”, describe the stages of the biofilm life?cycle and give examples where biofilms are beneficial and where they are problematic. (

Answer 1

BIofilm: It is comprises any group of microorganisms in which cells stick to each other and often also to surface.

stages of Biofilm life cycle:

stage 1: free swarming bacteria

stage 2:adhere to a surface using cell surface displayed adhesin molecule

stage 3:bacteria begins to divide and expression of further macromolecule allows them to stick together in small microcolonies

stage 4:as these colonies grow,they begin to secrete a complex mixture of carbohydrate,protein,lipids

they forms protective layer and stability for maturaing biofilm

stage 5:as biofilm recahes to maturity,no of factirs develop a heterogenous arrangement of cells and molecules within biofilm,this leads to dispersal of cells from cellular mass

stage 6:upon signal from environment,molecule are released that causes cell lysis and matrix dissemination.Many planktonic cells are now released and can find a new habitat.

eg:

-biofilm forms on tooth surface responsible for dental caries and periodontal disease.

-biofilms can harbor human infectious agents in environment,but also promote remediation of contaminated groundwater and soils.