Biomass production and astaxanthin accumulation of Haematococcus pluvialis in large-scale outdoor culture based on year-round survey: Influencing factors and physiological response

Abstract

Astaxanthin is an economically valuable carotenoid pigment, and most natural astaxanthin is produced via the large-scale cultivation of the green alga Haematococcus pluvialis in outdoor culture systems. The effects of various environmental factors on Haematococcus and the physiological response of algal cells have rarely been investigated at commercial production scale, which are important for maximizing the yield and efficiency of algae production. This study found that the light intensity and cumulative light intensity are the most important factors affecting the biomass production and astaxanthin accumulation in outdoor large-scale cultivation of Haematococcus based on a year-round survey, and the cumulative light intensity between 550 and 850 mol photons·m−2 was an optimal range for a reasonable productive harvest. The temperature, diurnal temperature difference, culture period and initial inoculation concentration were found to be associated with production performance. Light requirements for green cell growth and for astaxanthin accumulation of immotile cells were quite different, the late showed a very high tolerance to light intensity. Under high light intensity or low temperature, non-photochemical quenching seemed to play a role in quenching excess energy in red immotile spore cells. This study provided detailed information on Haematococcus biomass production and astaxanthin accumulation at big commercial scale via tubular photobioreactors, which is valuable for improvement of commercial production of Haematococcus.