DNA as a Nutrient: Novel Role for Bacterial Competence Gene Homologs

Open Access
Publisher Website
Google Scholar
Abstract
The uptake and stable maintenance of extracellular DNA, genetic transformation, is universally recognized as a major force in microbial evolution. We show here that extracellular DNA, both homospecific and heterospecific, can also serve as the sole source of carbon and energy supporting microbial growth. Mutants unable to consume DNA suffer a significant loss of fitness during stationary-phase competition. InEscherichia coli, the use of DNA as a nutrient depends on homologs of proteins involved in natural genetic competence and transformation in Haemophilus influenzae andNeisseria gonorrhoeae. Homologs of these E. coli genes are present in many members of the γ subclass ofProteobacteria, suggesting that the mechanisms for consumption of DNA may have been widely conserved during evolution.