Nor-Carotenoids as the Major Volatile Excretion Products of Cyanidium

Abstract

Cyanidium caldarium excretes a series of nor-carotenoids. A 110 litre culture was used to isolate and determine the structure of 5 compounds: methylheptone, geranylacetone, β-ionone, dihydrotrimethylnaphthalene, butenylidenetrimethylcyclohexene. An algal bioassay was used to determine their effectivness on the growth of photoautotrophic organisms. The growth of Anabaena, Synechococcus, Nannochloris and Cyanidium was found to be inhibited at concentrations between 10 to 50 ppm.