Geranyl Derivatives as Inhibitors of the Carotenogenesis in Synechococcus PCC 6911 (Cyanobacteria)

Abstract

The ability of several geranyl derivatives to inhibit carotenoid synthesis in Synechococcus (Cyanobacteria) was measured using a cyanobacterial bioassay. The inhibitory activity of differ­ent molecules varied according to chain length and substituents. Pseudoionone, farnesyl acetate, geranyl acetate, geranial and farnesol proved to be the most active derivatives tested. 6-Methylhept-5-en-2-one, farnesyl acetone, linalool and geranyl linalool exhibited no effect when employed in concentrations as high as 100 ppm. Besides phytofluene, ζ-carotene was accumu­lated after application of sublethal amounts of active geranyl derivatives. Cell growth and chlorophyll a synthesis were only slightly affected under conditions were carotenoid synthesis was markedly inhibited.