Acinetobacter calcoaceticus liberates chromosomal DNA during induction of competence by cell lysis.
A transformation assay was used to assay the amount of DNA present in the extracellular medium of a growing culture of Acinetobacter calcoaceticus. It was observed that small amounts of DNA were liberated during the entire exponential growth phase in a batch culture. Release of DNA could be fully accounted for by lysis of cells. Lysis was quantified via simultaneous measurement of beta-galactosidase activity of cells and supernatant, with a strain that contained a plasmid (pAPA100) with lacZ under control of a constitutive beta-lactamase promoter. In conclusion, no evidence could be obtained indicating that Acinetobacter calcoaceticus actively excretes DNA, to be used for DNA exchange.
Palmen
R
R
Department of Microbiology, E.C. Slater Institute, BioCentrum Amsterdam, The Netherlands.
Hellingwerf
K J
KJ
D016954:Acinetobacter calcoaceticus / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D002876:Chromosomes, Bacterial / Q000378:metabolism; D003470:Culture Media; D004269:DNA, Bacterial / Q000235:genetics / Q000378:metabolism*; D018014:Gene Transfer Techniques; D014170:Transformation, Genetic
D003470:Culture Media; D004269:DNA, Bacterial