Department of Biology, Nippon Medical School, 297, Kosugi-cho 2, Nakahara, Kawasaki, 211-0063, Japan.
Curr Microbiol. 2011 Jul;63(1):75-80. doi: 10.1007/s00284-011-9941-1. Epub 2011 May 6.
Phototrophic bacteria necessarily contain carotenoids for photosynthesis, and a few phototrophic purple bacteria accumulate unusual carotenoids. The carotenoids in the genera Phaeospirillum and Roseospira were identified using spectroscopic methods. All species of the genus Phaeospirillum contained characteristic polar carotenoids in addition to lycopene and hydroxylycopene (rhodopin); hydroxylycopene glucoside, dihydroxylycopene, and its mono- and/or diglucosides. From the structures of these carotenoids, their accumulation was suggested to be due to absence of CrtD (acyclic carotenoid C-3,4 desaturase) and to possession of glucosyltransferase. Species of the genus Roseospira have been reported to have unusual absorption spectra in acetone extract, and they were found to accumulate 3,4-didehydrorhodopin as a major carotenoid. This may be due to low activity of CrtF (acyclic 1-hydroxycarotenoid methyltransferase). The study concludes in identifying genus specific unusual carotenoids, which is probably due to characteristic nature of some carotenogenesis enzymes.
进行光合作用的光能细菌必然含有类胡萝卜素，而少数光能紫色细菌则会积累不寻常的类胡萝卜素。使用光谱方法鉴定了 Phaeospirillum 和 Roseospira 属中的类胡萝卜素。除了番茄红素和羟基番茄红素（叶黄素）外，Phaeospirillum 属的所有种还含有特征性的极性类胡萝卜素（羟基番茄红素葡萄糖苷、二羟基番茄红素及其单-和/或二葡萄糖苷）。根据这些类胡萝卜素的结构，它们的积累可能是由于缺乏 CrtD（环化类胡萝卜素 C-3、4 去饱和酶）和拥有葡萄糖基转移酶。据报道，Roseospira 属的种在丙酮提取物中有不寻常的吸收光谱，并且它们被发现积累 3,4-二脱氢叶黄素作为主要类胡萝卜素。这可能是由于 CrtF（非环 1-羟基类胡萝卜素甲基转移酶）的活性低。该研究结论是确定属特异性的不寻常类胡萝卜素，这可能是由于一些类胡萝卜素生物合成酶的特征性质。
