Abstract: Biological conversion of citral to geraniol was studied using Rhodotorula mucilaginosa CCZU-G5 as fermentation strain. The effects of culture time，co-substrate concentration，initial substrate concentration，cell quantity and the reaction time on selective hydrogenation of citral to geraniol were investigated to determine the optimal fermentation conditions. The results showed that after 28 h culturing，yeast cells reached the end of the logarithmic growth phase，in which the quantity and activity of the cells were at a high level. In the process of biological conversion，the optimal fermentation conditions were as follows：glucose concentration 40 g/L，initial citral concentration 4 g/L，yeast cell concentration 0.4 g/mL and reaction time 22 h. Under these conditions，citral conversion and geraniol selectivity reached 88.6% and 95.2%，respectively. The study lays the foundation for commercialized biosynthesis of geraniol.

Key words: Rhodotorula mucilaginosa, selective hydrogenation of citral, geraniol

摘要： 以黏红酵母CCZU-G5为菌株，通过对菌体培养时间、辅底物葡萄糖浓度、底物柠檬醛初始用量、菌体浓度及反应时间等条件的研究，考察其对柠檬醛选择性加氢反应的影响。结果表明，当培养28 h后，菌体达到对数生长期末期，此时菌体数量及活力处于较高水平。利用此时的菌体进行加氢反应过程中，最佳反应条件为：辅底物葡萄糖浓度40 g/L，底物柠檬醛添加浓度4 g/L，菌体浓度0.4 g/mL，反应时间22 h。在此条件下，柠檬醛转化率及对香叶醇的选择性分别达88.6%与95.2%。此研究为生物合成香叶醇的工业化奠定基础。

关键词: 黏红酵母, 柠檬醛选择性加氢, 香叶醇