USE OF RANDOM AMPLIFIED POLYMORPHIC DNA (RAPD) FOR GENERATING SPECIFIC DNA PROBES FOR MICROORGANISMS

We report the rapid generation of DNA probes for several Azospirillum strains.This method does not require any knowledge of the genetics and /or the molecular biology of the organism (genome) to be investigated. The procedure is based on the generation of random amplified polymorp hic DNA (RAPD) fingerprints using primers with an embedded restriction site. The amplification product(s) peculiar to one strain or common t o two or more strains can be purified, cloned, sequenced and used as m olecular probes in hybridization experiments for the detection and ide ntification of microorganisms. We have tested this methodology in the nitrogen-fixing bacterium Azospirillum by amplifying the total DNA ext racted from several Azospirillum strains. We have used amplification b ands with different specificity as molecular probes in hybridization e xperiments performed on amplified DNA. Results obtained have demonstra ted the usefulness of this methodology for Azospirillum. Its use in mi crobial ecology studies as a general strategy to generate specific DNA probes is also discussed.