Roles of Extracellular DNA in Bacterial Ecosystem

Abstract

Extracellular DNA in the natural environment is a source of nutrients and gene pools for bacteria. In sediments and biofilms, gene transfer must occur among bacteria via extracellular DNA because the concentrations of both exogenous DNA and cells are high. Some bacteria actively release naked DNA or the membrane vesicle containing the DNA into the environment. Some bacteria also produce extracellular DNA by suicide and fratricide. Released DNA is used for DNA repair, transformation, and generation of genetic diversity. DNA is required for the initiation of biofilm formation and stabilization of biofilms. In biofilms, gene exchange and mutation must occur to generate diversity.