[Heterologous transformation: search for an explantation of the high effectiveness of Bacillus subtilis transformation achieved by using Bacillus natto DNA].

A higher efficiency of B. subtilis cells transformation by B. natto DNA is true for every concentration of DNA and is not due to the helping effect known for streptococci, strain Challis. In competition experiments for DNA uptake unlabelled B. natto and B. subtilis DNAs when added to transforming H3-DNA reduced the radioactivity of the samples by a factor of three and two, respectively. A conclusion is drawn that a higher rate of B. natto DNA penetration to the B. subtilis cells results in a higher efficiency of their transformation.