Identification of cyanobacteria by polymorphisms of PCR-amplified ribosomal DNA spacer region

The 16S-23S ribosomal DNA spacer region of selected cyanobacterial strains was amplified by the polymerase chain reaction using primers to conserved flanking sequences. Single or multiple rDNA amplification products were generated depending on the strain and primer pair. Species could generally be distinguished on the basis of size heterogeneity of the products. Analysis of restriction digests of the amplified rDNAs indicated polymorphisms useful in identification. Four enzymes (Hin fI, Dde I, Alu I, Taq I) generated restriction fragment length patterns that could discriminate between the cyanobacteria to the taxonomic levels of genus and species. This approach should prove useful in the rapid identification of cyanobacteria.