ELECTRON MICROSCOPIC STUDIES OF EXTRAPLASTIDIC ASTAXANTHIN IN HAEMATOCOCCUS12

Publisher Website
Google Scholar
Abstract
The ketonic carotenoid astaxanthin accumulates in perinuclear cytoplasm characterized by a network of ribosome-coated endoplasmic reticulum segments, free ribosomes, dictyosomes in active stages of vesicle formation, and mitochondria. The pigment granules form in the ground substance and not within any organelle or vesicle. Coalescence of the globular granules results from increasing quantities of astaxanthin formed as the cells age. The gross differences in fixation image following glutar-aldehyde-KMnO4 and glutaraldehyde-OsO4 are illustrated, and the need for a variety of fixations upon which interpretations are based is emphasized. The bright red coloration of akinetes is due to a masking of the chlorophyll by the massive astaxanthin deposits rather than any breakdown of the chloroplast thylakoids.

This publication has 14 references indexed in Scilit: