Photoheterotrophy and chemoheterotrophy among unicellular blue-green algae
Thirty eight axenic strains belonging to the Chroococcales were screened for the ability to grow photoheterotrophically in the light with glucose in the presence of 10-5 M DCMU, which inhibits photoautotrophic growth. Seven strains could do so, and four of them could also grow chemoheterotrophically, though more slowly, with glucose in the dark. Six are members of the genus Aphanocapsa and one of the genus Chlorogloea. The remaining 31 strains examined appear to be obligate photoautotrophs. A quantitative study of the growth behaviour of one strain, Aphanocapsa 6714, fully confirmed its facultative photoheterotrophy and chemoheterotrophy.