?EＥｕｇｌｅｎａ ｇｒａｃｉｌｉｓ ｚ?F，ｂｌｅａｃｈｅｄ ｍｕｔａｎｔのカロチノイド組成と光による変動

Abstract

The permanent bleached (streptomycin) mutant of Euglena gracilis z contained 0.25pg/cell of total carotenoid when cultured in a medium with glucose and glutamate as the major carbon sources in the dark for 10 days, while the mutant contained 0.80pg/cell when cultured with illumination. The dark-grown cells increased the carotenoid content upon exposure to light depending on the light intensity. The dark-grown cells contained antheraxanthin as the major carotenoid constituent; β-carotene, ethinenone and euglenanone were other constituents. Upon illumination of the dark-grown cells, euglenanone was increased 16-fold but the content of antheraxanthin was not changed. In the bleached mutant of E. gracilis containing no chloroplasts, euglenanone appears to function to protect cells from damaging action of light.