FIG. 2.

Plasmids isolated from B. subtilis (natto) strains. Plasmids from the strains were subjected to pulsed-field gel electrophoresis. The conditions were as follows: 2.3 V/cm, a pulse time of 6 s, and a running time of 15 h. Lanes + contained BglII digests. Bands not digested by BglII indicated by arrowheads are the small plasmids (monomeric and dimeric forms) that migrated as cccDNA because they did not have a BglII site. The arrow indicates the area where large plasmids migrated. Several other bands are probably bands for open circular forms because of susceptibility to BglII digestion. Lanes M contained the HindIII digests of λphage DNA (left) and genomic DNA of λphage (right) as size markers.