Intra-specific phenotypic and genotypic variation in toxic cyanobacterial Microcystis strains

J Appl Microbiol. 2008 Aug;105(2):407-15. doi: 10.1111/j.1365-2672.2008.03754.x. Epub 2008 Mar 18.


Aims: We determined if the intra-specific genetic diversity of Microcystis aeruginosa correlates with phenotypic characteristics.

Methods and results: Microcystis aeruginosa isolates from various Japanese waters were characterized using genetic analyses based on the 16S-23S rDNA internal transcribed spacer (ITS) region and DNA-independent RNA polymerase (rpoC1) gene sequences. In addition, morphological and biochemical properties, and the toxicity of M. aeruginosa strains were determined. We found a correlation in phylogenetic clusters of the ITS region and rpoC1 gene sequences. Using a polyphasic approach, genotypic and phenotypic variations in M. aeruginosa showed that the three genetic lineage groups are comprised of a particular phenotype or subgroup of closely related phenotypes. However, some strains had high phenotypic and genotypic diversity compared to the three lineage groups and did not show distinct lineages; therefore, these strains were designated as the 'complex group'.

Conclusions: The 'complex group' consisted of genetically and phenotypically incoherent and high diverse populations in M. aeruginosa, although some genotypes or lineages displayed consistent phenotypes.

Significance and impact of the study: The polyphasic approach combining phenotypic and genetic characterization was effective for comprehending distinct lineages and discriminating the potential complexity of M. aeruginosa populations at the intra-species level.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • DNA, Ribosomal Spacer / analysis
  • Eutrophication
  • Fresh Water
  • Genetic Variation
  • Genotype
  • Microcystis / classification*
  • Microcystis / genetics
  • Microcystis / metabolism
  • Phenotype
  • RNA, Ribosomal, 16S / analysis
  • Ribotyping
  • Water Microbiology*


  • DNA, Ribosomal Spacer
  • RNA, Ribosomal, 16S