The Absence of Protochlorophyll(ide) Accumulation in Algae with Inhibited Chlorophyll Synthesis

Golenkinia, Chlorella protothecoides, and mutant C-2A′ of Scenedesmus were grown in darkness and on media in which chlorophyll synthesis is reduced significantly. The pigments were analyzed by spectrophotometry or by paper chromatography and compared with similar extracts from light-grown algae and dark-grown beans. No protochlorophyll(ide) was present in the dark-grown algae indicating that chlorophyll synthesis is blocked by a mechanism other than feedback regulation of aminolevulinic acid synthesis by protochlorophyll(ide) which has been proposed for flowering plants.