Biochemical analysis of the carotenoid pattern in zygospores of Chlamydomonas reinhardtii

Matthias Bauch, Sonja Werner, Judith Köhler, and Martin Lohr

Institute of General Botany, Johannes Gutenberg-University Mainz, Germany

Mature zygospores of C. reinhardtii display a bright orange color which is due to a massive accumulation of carotenoids. We have analyzed the pigment pattern of zygospores by means of high-performance liquid chromatography (HPLC) and found about 10 major and 15 minor additional analyte peaks as compared to vegetative cells. Here we present a more detailed characterization of the new pigments showing that the vast majority are acyl esters of hydroxy-ketocarotenoids. For the major analytes, we have analyzed after mild saponification the nature of the chromophores by analytical HPLC, diagnostic derivatization reactions, and mass spectrometry, and currently we are investigating the identity of the acyl moieties by gas chromatography. In addition, we started to compare the ketocarotenoid pattern of zygospores with those of extracts from the well-known astaxanthin-producing chlorophyte Haematococcus pluvialis and the resting spores of several other green algae. Preliminary data indicate varying ratios of β-carotene vs. α-carotene derived ketocarotenoids, with C. reinhardtii and H. pluvialis representing two opposite extremes.

e-mail address of presenting author: bauch@students.uni-mainz.de