Comparative metabolic and transcriptomic analysis of macrozoids and palmelloid cells of Haematococcus pluvialis related to astaxanthin accumulation

In this work, we propose a metabolomic and transcriptomic comparative study between a vegetative state and intermediate reddish palmelloid state growing in continuous culture conditions, giving rise to a profound understanding of the first steps of the adaptation of Haematococcus pluvialis to nitrogen limitation and the correlation with astaxanthin biosynthesis. In addition, other related metabolic pathways as fatty acid biosynthesis, starch accumulation, citric acid cycle, and amino acid biosynthesis have been analyzed. Understanding the molecular basis of astaxanthin accumulation will be useful for the optimization of astaxanthin production. Haematococcus lacustris (strain CCAP 34/8) was grown photoautotrophically in six jacketed bubble columns (0.06 m diameter, 0.50 m height), containing 1.8 L of cell suspension. Photobioreactors were continuously sparged with air (6.6 L (per L culture)/h). Temperature was maintained at 25ºC by flowing thermostated water through the jacked of the photobioreactors. The pH was controlled by on demand injection of pure CO2 into the air stream entering the culture maintained to 7.0. Each photobioreactor was illuminated by six surrounding Phillips Master TL5HO 24W/840 white-light lamps in a solar cycle simulated (12h/12h) with maximum impinging irradiance on the reactor surface of 1500 uE m-2 s-1. Experiments were carried out in continuous mode, at dilution rate of 0.8/day. The basal inorganic culture medium used to feed the reactor was previously described (Del Río et al., 2015). The medium was supplied with sodium nitrate, as to reach the final nitrate concentration indicated (15 or 2 mM).Escribe un mensaje.