After transformation, we extract the PQQ plasmid from EP2 (Bacillus subtilis natto PQQ) and amplify the DNA, then run the electrophoresis. The result illustrates the successful transformation based on the band all on the same height level.

Figure 1. Electrophoresis of PQQ plasmid.
Comparing the plasmid(BBa_K3830012, left) stored in E.coli JM109 to plasmid extracted from modified
Bacillus subtilis natto(right).


Also, we run PCR to make multiple copies of a segment of the plasmid, to sequence the gene of PQQ.

  1. B. subtilis natto PQQ
  2. E. coli JM109
  3. Positive control (Pure plasmid)

Antibiotics resistance bacteria selection

As the kanamycin resistant gene in our PQQ plasmid but in the wild-type Bacillus subtilis natto, we carry out the plate selection with kanamycin to confirm the transformation is successful.

Growth curve

By the growth curve, we could see the differences between the wild-type and the Bacillus subtilis natto PQQ. And also, the EP2 (Bacillus subtilis natto PQQ), with the PQQ plasmid, grows more fast and more quickly after entering the log phase and stationary phase.