Plasmid transformation of Azospirillum brasilense |
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Authors: | Renato Fani Marco Bazzicalupo Patrizia Coianiz Mario Polsinelli |
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Institution: | Department of Animal Biology and Genetics, Via Romana 17, 50125 Florence, Italy |
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Abstract: | Abstract Plasmid transformation of the nitrogen-fixing bacterium Azospirillum brasilense is described. A modification of the method of Hanahan 1] was used to transform this bacterium with the 20-kb plasmid pRK290. The efficiency of transformation ranged from 200–1000 transformants per μg of plasmid DNA according to DNA concentration. Ca2+, Mn2+ and K+ were essential for competence, while Rb+ and hexamine cobalt(III) chloride did not appear necessary. The length and the temperature of heat-pulse during transformation affected the efficiency of transformation. The response to different numbers of plasmid molecules was linear, in the range of 0.05–1.0 μg of DNA. No transformants were obtained with pRK290 plasmid DNA linearized with Eco RI. The transformability of different strains of Azospirillum has been compared. |
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Keywords: | Azospirillum brasilense competence plasmid DNA transformation |
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