ISSN:
1432-072X
Keywords:
Plasmid DNA
;
Chromosomal DNA
;
release from cells
;
Soil bacteria
;
Natural genetic transformation
;
Competence
;
Bacterial DNase activities
;
Gene transfer
;
Bacillus subtilis
;
Acinetobacter calcoaceticus
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract The release of chromosomal and plasmid DNA from Acinetobacter calcoaceticus and Bacillus subtilis cultivated in minimal medium and broth over a period of 50 h was monitored and related to growth phase, autolysis, DNase production and natural competence. The released DNAs were biologically active in natural transformation. In addition, the circular integrity of a released B. subtilis shuttle vector (pHV14) was demonstrated by artificial transformation of Escherichia coli. In cultures of both strains high molecular weight DNA accumulated, particularly during the stationary and death phase (up to 30 μg ml-1). Generally, despite the presence in culture fluids of DNase activity (and of an intracellular enzyme, catalase, indicating some cell lysis) there was high transforming activity of chromsomal and plasmid DNA even 40 h after the cultures reached the stationary phase. In cultures of B. subtilis in minimal medium a presumably active release of intact plasmids and chromsomal DNA occurred during the competence phase. The release of biologically functional DNA during essentially all growth phases of a gram-positive and a gram-negative member of soil bacteria might facilitate horizontal gene transfer by transformation in natural habitats.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00263005
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