Astaxanthin biosynthesis enhanced by reactive oxygen species in the green algaHaematococcus pluvialis |
| |
Authors: | Makio Kobayashi |
| |
Institution: | (1) Research Laboratory of Higashimaru Shoyu Co. Ltd., 100-3, Tominaga, Tatsuno, 679-4167 Hyogo, Japan |
| |
Abstract: | The unicellular green algaHaematococcus pluvialis has recently attracted great interest due to its large amounts of ketocarotenoid astaxanthin, 3,3′-dihydroxy-β,β-carotene-4,4′-dione,
widely used commercially as a source of pigment for aquaculture. In the life cycle ofH. pluvialis, astaxanthin biosynthesis is associated with a remarkable morphological change from green motile vegetative cells into red
immotile cyst cells as the resting stage. In recent years we have studied this morphological process from two aspects: defining
conditions governing astaxanthin biosynthesis and questioning the possible function of astaxanthin in protecting algal cells
against environmental stress. Astaxanthin accumulation in cysts was induced by a variety of environmental conditions of oxidative
stress caused by reactive oxygen species, intense light, drought, high salinity, and high temperature. In the adaptation to
stress, abscisic acid induced by reactive oxygen species, would function as a hormone in algal morphogenesis from vegetative
to cyst cells. Furthermore, measurements of bothin vitro andin vivo antioxidative activities of astaxanthin clearly demonstrated that tolerance to excessive reactive oxygen species is greater
in astaxanthin-rich cysts than in astaxanthin-poor cysts or astaxanthin-less vegetative genesis and carotenogenesis, and the
accumulated astaxanthin in cysts can function as a protective agent against oxidative stress damage. In this study, the physiological
roles of astaxanthin in stress response and cell protection are reviewed. |
| |
Keywords: | antioxidant astaxanthin cyst cell environmental stress Haematococcus pluvialis reactive oxygen species |
本文献已被 SpringerLink 等数据库收录! |
|