Classification ofChlorella strains by cell appearance and group sera

Employing 32 strains ofChlorella, sizes and forms of daughter and mother cells and the cross-reaction of group sera were examined for the classification of these organisms. The cell size distribution of log phase cells grown in a glucose medium under limited light was not affected by culture temperature. The ratio of minor and major axes of ellipsoidal cells remained almost unchanged in any given species, independent of culture conditions including culture age. The taxonomic arrangment based on the cell appearance corresponded well with that based on the serological groups. In conclusion, at least 26 of the 32 strains were classified into 9 species based on the cell appearance and group sera.