Carotenoid composition in the cyanobacterium Phormidium laminosum Effect of nitrogen starvation

Publisher Website
Google Scholar
Abstract
When pigments of the non‐N2‐fixing cyanobacterium Pharmidium laminosum were carefully extracted and analyzed in a completely O2‐free atmosphere, by either high performance liquid chromatography (HPLC) or thin layer chromatography (TLC) , the presence of only two carotenoids (namely, β‐carotene and nostoxanthin) was detected. However, exposure of pigments to an air atmosphere during their manipulation led to the rapid appearance in the organic extracts of at least three additional carotenoids (identified as caloxanthin, zeaxanthin and β‐cryptoxanthin). This fact could explain in the presence in cyanobacteria of such hydroxylated acrivatives of β‐carotene widely reported in the literature. Nitrogen starvation also resulted in an important decrease on the relative β‐carotene/nostoxanthin content of cells, suggesting that this nutritional condition affects thylakoid membranes more drastically than cytoplasmic membranes.