SPECIFIC AMPLIFICATION AND RESTRICTION POLYMORPHISMS OF THE CYANOBACTERIAL RIBOSOMAL-RNA OPERON SPACER REGION

Forty-two strains of cyanobacteria commonly associated with toxic bloo m events and representing 10 cyanobacterial genera were examined by RF LP analysis of the PCR amplified 16S-23S rRNA gene internal transcribe d spacer (ITS). A total of 97 different DNA profiles were generated by the application of 8 restriction endonucleases to digest the PCR prod ucts. The length of the PCR products obtained for strains assigned to the same genus seemed to be a useful taxonomic character and could pro bably be used for rapid identification, Nine characteristic amplificat ion products delineated the 10 genera studied. Intrageneric strain dif ferentiation was provided by restriction digest profiles which, when c ombined for each strain, resulted in 27 distinct genotypes. Specific a mplification of cyanobacterial strains from mixed populations and envi ronmental samples containing algae and heterotrophic bacteria was poss ible due to the use of a cyanobacteria specific 16S rRNA gene-directed PCR primer. The generic relatedness observed between the taxa studied coincided with the taxonomic identification of the studied strains, p articularly within the genera Anabaena and Microcystis.