Endophytic Fungi In Taxus Yunnanensis Immobilized Ggpp Enzyme

Endophytic fungus strain 12.3.2 were isolated from the Taxus Yunnanensis, which had the ability to produce the taxol or its derivates, were the study subjects in this paper.The effects of medium compositions and culture conditions on the growth of strain 12.3.2 were investigated. The temperature, carbon sources, nitrogen sources, pH, the concentration of the media, saccharides and the requirement of some general vitamins as well as the relationship of the aim strain were studied. The result showed that temperature had significant effect on the growth of the aim endophytes. In the neutral conditions, it was suitable for the growth of the aim endophytes. The dry weight of mycelium had positive correlation with the concentration of culture medium.To determine the immobilization efficiency of conidia in Taxus yunnanensis, the TTC method was established. Conidia of Fungal Endophytes in Taxus yunnanensis 12.3.2 were immobilized with sodium alginate. Then, the TTC method was applied to examine the viability of conidia. And the effects of diameter of microbeads sodium, alginate concentration, calcium chloride concentration, amount of condia unit Calcium Alginate gel, time and temperature in immobilization were also analyzed. The results showed that the under the conditions of microbeads diameter 2 mm , 40°C, 4.0 % sodium alginate, 2.6 % calcium chloride, 6 hour incubation, 2.3×10~9 condia /10 g Calcium Alginate gel and 46 % the embedded rate the immobilization efficiency was the highest. The TTC method can be used for assaying the immobilization efficiency. And the immobilization conidia exhibited the better fermentation characteristics.Geranylgeranyl diphosphate synthase (GGPP synthase) supplied the essential acyclic precursor for Taxol biosynthesis. This enzyme belonged to the isopentenyl transferase, which occurred electronic nucleophilic coupling, catalyzed FPP and IPP to form GGPP. Through using the function, controlled diterpene and in tetraterpene biosynthesis way branching point, and started the taxol biosynthesis. The GGPP synthase in the aim endophytic fungus was qualitative analyzed .