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.

Tolerance to mercury chloride in Scenedesmus strains.

Mercury chloride toxicity was investigated in two strains of Chlorella and in a strain of Scenedesmus isolated from polluted areas in Tuscany (Italy). No Hg resistance was found in the autotrophic microorganisms isolated, but Scenedesmus sp. strain AR-2489, isolated from the Arno river, was able to grow at concentrations of up to 5 micrograms ml-1 of Hg.