Enhanced Carotenoid Biosynthesis by Oxidative Stress in Acetate-Induced Cyst Cells of a Green Unicellular Alga, Haematococcus pluvialis

Abstract

In a green alga, Haematococcus pluvialis, a morphological change of vegetative cells into cyst cells was rapidly induced by the addition of acetate or acetate plus Fe2+ to the vegetative growth phase. Accompanied by cyst formation, algal astaxanthin formation was more enhanced by the addition of acetate plus Fe2+ than by the addition of acetate alone. Encystment and enhanced carotenoid biosynthesis were inhibited by either actinomycin D or cycloheximide. However, after cyst formation was induced by the addition of acetate alone, carotenoid formation could be enhanced with the subsequent addition of Fe2+ even in the presence of the inhibitors. The Fe2+-enhanced carotenogenesis was inhibited by potassium iodide, a scavenger for hydroxyl radical, suggesting that hydroxyl radical formed by an iron-catalyzed Fenton reaction may be required for enhanced carotenoid biosynthesis. Moreover, it was demonstrated that four active oxygen species, singlet oxygen, superoxide anion radical, hydrogen peroxide, and peroxy radical, were capable of replacing Fe2+ in its role in the enhanced carotenoid formation in the acetate-induced cyst. From these results, it was concluded that oxidative stress is involved in the posttranslational activation of carotenoid biosynthesis in acetate-induced cyst cells.

ASTAXANTHIN ACCUMULATION IN HAEMATOCOCCUS PLUVIALIS (CHLOROPHYCEAE) AS AN ACTIVE PHOTOPROTECTIVE PROCESS UNDER HIGH IRRADIANCE1

“…Moreover, only in this unique induction system, Haematococcus cells recovered from high light stress and entered the vegetative stage. Our results indicate that astaxanthin acts both as a light screen, as suggested by Yong and Lee (1991) and Hagen et al (1994), and as a physicochemical barrier, as suggested by Hagen et al (1993) and Kobayashi et al (1993).…”

EFFECT OF DISSOLVED OXYGEN PARTIAL PRESSURE ON THE ACCUMULATION OF ASTAXANTHIN IN CHEMOSTAT CULTURES OF HAEMATOCOCCUS LACUSTRIS (CHLOROPHYTA)

“…More work is necessary to verify the effect of PFD. Kobayashi et al (1993), Tjahjono et al (1994), and the present study, nevertheless, demonstrate that oxygen stress is a major factor in inducing the synthesis of astaxanthin in Haematococcus cells. Haematococcus is a potential industrial source of astaxanthin, which is a natural colorant for fish and poultry products (Bauernfeind 1981).…”

“…On the other hand, at 20-076 O,, both the fraction of motile cells and astaxanthin content decreased with 0,. If we are to accept the argument that the dissolved Op partial pressures in the cultures determined the rate of diffusion of endogenously generated 0, from photosynthesis and the intracellular concentration of O,, this study appears to support the claim of Kobayashi et al (1993) and Tjahjono et al (1994) that the synthesis of astaxanthin in Haematococcus is regulated by light via photosynthetically generated 0,. However, we could not completely rule out the possibility of other causes (e.g.…”

Aerobic condition increases carotenoid production associated with oxidative stress tolerance inEnterococcus gilvus

“…Carotenoids can act as antioxidants (Young & Lowe, 2001) and their production can be induced by oxidativeor light-induced stress (Kobayashi et al, 1993;Takano et al, 2011). In LAB, although several antioxidants are induced by oxidative stress (Pedersen et al, 2008), not much is known regarding the relationship between carotenoid production and stress responses.…”

“…Carotenoid production can be induced by environmental stresses. In algae, oxidative stress induces the production of astaxanthin (Kobayashi et al, 1993). In case of a nonphotosynthetic bacterium, Thermus thermophilus, Takano et al (2011) reported that light could induce the production of thermozeaxanthin, which contributed to a DNA repair system.…”