Specific amplification and restriction polymorphisms of the cyanobacterial rRNA operon spacer region

Forty-two strains of cyanobacteria commonly associated with toxic bloom events and representing 10 cyanobacterial genera were examined by RFLP analysis of the PCR amplified 16S-23S rRNA gene internal transcribed spacer (ITS). A total of 97 different DNA profiles were generated by the application of 8 restriction endonucleases to digest the PCR products. The length of the PCR products obtained for strains assigned to the same genus seemed to be a useful taxonomic character and could probably be used for rapid identification, Nine characteristic amplification products delineated the 10 genera studied. Intrageneric strain differentiation was provided by restriction digest profiles which, when combined for each strain, resulted in 27 distinct genotypes. Specific amplification of cyanobacterial strains from mixed populations and environmental samples containing algae and heterotrophic bacteria was possible 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, particularly within the genera Anabaena and Microcystis.