Culture of the astaxanthin-producing green algaHaematococcus pluvialis 1. Effects of nutrients on growth and cell type

Optimization of biomass, total carotenoids and astaxanthin production in Haematococcus pluvialis Flotow strain Steptoe (Nevada, USA) under laboratory conditions

“…20 and 12 in the cultures at 12 mM acetate under 35 µmol m -2 s -1 and 85 µmol m -2 s -1 , respectively) which agrees with the results found by various authors (Borowitzka et al, 1991;Kakizono et al, 1992). The latter authors have assayed the supplementation of acetate both to increase the vegetative growth of green cells and to induce the formation of cysts.…”

“…According to this author, there are strain d i f f e r e n c e s i n t h e m e c h a n i s m o f N utilization. On the other hand, it should be borne in mind that a high cell concentration of vegetative cells, transferred to an inductive carotenogenic situation, does not always accumulate astaxanthin (Borowitzka et al, 1991). These authors, working with two strains of H. pluvialis from Switzerland and Finland,respectively) found that although nitrate, ammonium and urea gave similar final cell yields, the best nitrogen source for both growth and carotenoid accumulation was nitrate, since the carotenogenesis was slightly inhibited in the ammonium-and urea-grown cultures.…”

“…The methods assayed here included mixo-and heterotrophic growth, using sodium acetate as the organic c a r b o n s o u r c e a s d i d o t h e r a u t h o r s (Kobayashi et al, 1991(Kobayashi et al, , 1992(Kobayashi et al, , 1997bBorowitzka et al, 1991;Gong and Chen, 1997;Orosa et al, 2001). Although most work has found enhanced growth rates with acetate and has recommended mixotrophic and heterotrophic cultivation system for commercial application, it is also true that some work has reported slow cell growth and low final cell densities when growth is carried out in batch mode (Borowitzka et al, 1991;Tjahjono et al, 1994;Hata et al,c u l t u r e s , r e s p e c t i v e l y ) . I n d e e d , a n d according to Orosa et al (2001), the induction of astaxanthin production is t r i g g e r e d b y s t r e s s f a c t o r s t h a t a r e cumulative of the physiological state of the cells and the culture conditions.…”

“…Currently, commercial production of astaxanthin by H. pluvialis has been reported based on both strategies using a two-step culture [Cyanotech Corporation and Aquasearch Inc., Microbio Resources Inc., and Algatec Inc. (Bubrick, 1991)] and/ or a single step process [Microgaia Inc. (Olaizola, 2000)] and both processes are carried out under photoautotrophic conditions. Although mixotrophic metabolism in this alga has been studied and documented (Borowitzka et al, 1991;Kobayashi et al, 1992;Gong and Chen, 1997), and heterotrophic growth has been reported in some strains of H. pluvialis (Kobashayi et al, 1992;Hata et al, 2001), these conditions have not been applied in cultures at commercial scale.…”

“…Since the effect of acetate is influenced by the pH of the medium (Borowitzka et al, 1991) the pH was measured and adjusted to a predefined value of 6.0, every three days. In preliminary assays, the Steptoe strain preferred slightly acid pH (data not included) and since the concentrated sodium acetate solution used as stock had a pH of 8.11, the adjustment in pH regulated the initial pH (that varied from 6.0 to 8.7 before adjusting).…”