Fractionation of Transformable Bacteria from Competent Cultures of Bacillus subtilis on Renografin Gradients

Abstract

A population of Bacillus subtilis can be fractionated into at least two components on the basis of their buoyant densities on a Renografin gradient. In competent cultures, most, and perhaps all, of the competent bacteria appear in the lighter fraction which composes 2 to 10% of the bulk population. These “lighter” bacteria are the only bacteria capable of incorporating transforming deoxyribonucleic acid.