Inducing Mechanism of Acetate on Astaxanthin Synthesis in Haematococcus pluvialis

Abstract:

Nitrate reductase (NR) increased 1.6 folds in the acetate-added culture of Haematococcus pluvialis.Consequently，the algal cells absorbed nitrate quickly for heterotrophic growth，leading to ultimately short supply of nitrogen，which in turn inhibited the formation of chlorophyll and the activity of ribulose-1，5-bisphosphate carboxylase (Rubisco).When astaxanthin synthesis was triggered on the fourth day，nitrate concentration，chlorophyll content and Rubisco activity reduced by 96.7%，71.9% and 80%，respectively.By contrast，in the culture without acetate，chlorophyll content and Rubisco activity decreased only 47.2%，27.3% and 4.4% at the end of the experiment with no astaxanthin accumulated.

Key words:Haematococcus pluvialis，Astaxanthin，Acetate，NR，Rubisco