类胡萝卜素在光合细菌P4株中生物合成及紫外线防护

Influential Factors of Biosynthesis of Carotenoids in Photosynthetic Bacteria P 4 Strain and Carotenoids’ Activity in Protecting Eucell Against Ultraviolet

从光合细菌Ｐ４株提取的类胡萝卜素的主要成分为β－胡萝卜素，提取率约为０．３９％．菌体中类胡萝卜素的生物合成受环境中多种因素的影响．弱光、厌氧、较高温度有利于类胡萝卜素的生物合成，培养液中Ｆｅ３＋离子浓度在５ｍｇ／Ｌ左右对其合成有明显的促进作用，碳源、氮源对类胡萝卜的生物合成影响不大，但对菌体生长速率有明显影响，从而也影响到获得类胡萝卜素的绝对量．从Ｐ４菌体中提取的类胡萝卜素对真核细胞有良好紫外线防护作用，当培养液中其含量仅为０．２μｇ／Ｌ时，保护率接近６０％．

carotene is the main component of carotenoids extracted from photosynthetic bacteria P 4. The ertractive rate is about 0.39%. The biosynthesis of carotenoids in P 4 cell are affected by many factors in the enviroment. It would be beneficial to the biosynthesis under anarobic condition, weak light and warm temperature. The biosynthesis are also obviously promoted by the “Fe 3+ ” ion concentration that is about 5mg/L in the culture. Difference in carbon and nitrogen sources has no evident effect on the biosyntheses. But the growth rate of P 4 is obviously influnced by these sources. Therefore different absolute quatities of carotenoids would be gained by using different sources.The carotenoides from P 4 cell has the ability to protect eukaryotic cell against ultraviolet. When its concentration is only 0.2 μg/L , the protective rate reaches nearly 60%.