Stable transformation of Chromobacterium violaceum with a broad-host-range plasmid.
Stable transformants of Chromobacterium violaceum were obtained by high-voltage electroporation with a 7-kilobase binary plasmid. The technique was reliable, reproducible, and simple, with efficiencies of 10(5) transformants/microg of plasmid DNA. The electrical conditions that resulted in the highest efficiencies were short pulse length (4.4-4.5 ms) and high voltage (12.5 kV/cm). The numbers of transformants were almost the same during the growth exponential phase (variation at optical density) and resulted in the highest efficiencies at DNA concentration of 250 pg/ml. Saturation appeared to begin at 4 microg/ml of DNA. This method of C. violaceum transformation should enhance the genetic and biotechnological research by providing a valuable, widely used procedure of introducing DNA into this bacterium.
Broetto
L
L
Centro de Biotecnologia, Universidade Federal do Rio Grande do Sul, Av. Bento Gonçalves, 9500-Prédio 43421, C.P. 15005-CEP: 91501-970, Porto Alegre, RS, Brazil.
Cecagno
R
R
Sant'anna
F H
FH
Weber
S
S
Schrank
I S
IS
D002861:Chromobacterium / Q000235:genetics*; D018274:Electroporation / Q000379:methods; D010957:Plasmids / Q000235:genetics*; D014169:Transformation, Bacterial