Genotypic diversity and typing of cyanobacterial strains of the genus Arthrospira by very sensitive total DNA restriction profile analysis.

Arthrospira maxima and A. platensis are two species of cyanobacteria cultivated and sold as health food, animal feed and source of food additives and fine chemicals. The genotypic diversity of several strains attributed to these two species on the basis of morphological criteria was investigated using very sensitive total DNA restriction profile analysis. The restriction profiles were obtained after sodium dodecyl sulphate polyacrylamide gel electrophoresis and silver staining. The unweighted pair-group method using arithmetic averages applied to the matrix of Dice similarity coefficient values clustered the electropherograms of the strains in two well-separated genotypic groups. These clusters corresponded to those obtained with morphological criteria. The molecular approach used was also able to type the examined strains.