[Influence of DCMU on the formation of lipids and fatty acids, and on the ultrastructure of Euglena gracilis (author's transl)]

Abstract

Euglena gracilis Klebs (strain Z) was grown heterotrophically in the dark for 6 days. Subsequently, the cells were grown photoautotrophically under white fluorescent light with varying amounts of 3-(3,4-dichlorophenyl)-1,1 dimethyl urea (DCMU) (1.7X10(-9)--1.0X10(-5)mol/l) added to the nutrient medium. Under non-photosynthetic conditions (addition of 10(-6)--10(-5)mol DCMU/l), the cells still produced chloroplast structures and a considerable percentage of compounds typical for chloroplasts, such as galactolipids (40-50%), chlorophylls (40%), and polyunsaturated C16 and C18 fatty acids (16:2, 16:3, 16:4, 18:2, 18:3) (65%). The results indicate that under these conditions the above compounds are synthesized from carbon sources outside the chloroplasts.