大豆甾醇是近年来国际认可的降胆固醇新资源食品，目前主要通过化学合成途径获得，未有生物合成的报道。前期研究发现，米曲霉含有的氧化固醇结合蛋白（OSBP）与大豆甾醇的生物合成密切相关。本研究拟克隆米曲霉氧化固醇结合蛋白（AoOSBP）的基因，实现其在大肠杆菌中异源高效表达。鉴定AoOSBP重组蛋白与大豆甾醇类物质的结合能力；制备抗体，通过Western blotting定量分析在不同发酵时期的AoOSBP的表达差异，结合半定量或实时定量 PCR，分析AoOSBP在米曲霉发酵不同时期AoOSBP表达水平与大豆甾醇的量效关系；经过免疫荧光共定位技术，显示在不同发酵时期AoOSBP米曲霉菌丝体的亚细胞区位，阐明在米曲霉发酵过程中大豆甾醇合成代谢的分子转运路径，为研究大豆甾醇合成代谢提供科学数据。

Soybean sterols are recently widely accepted as novel food resources with lowering serum cholesterol in the international food industry, which are produced by chemosynthesis, no paper report their synthesis from Microorganisms . Based on previous studies, one Aspergillus oryzae gene oxysterol binding protein (OSBP) is associated with soybean sterol synthesis, which has not been reported. This project focuses on cloning and expression OSBP gene from Aspergillus oryzae, Western blotting analysis and immunofluorescence localization, the objective is to explore the soybean sterols level in the ferment at different fermentation time-points and explore sterols transportation in various parts of A. oryzae mycelium at the sub-cellular level. Combined with the different types and levels of sterols during fermentation, we try to reveal tranport pathway of soybean sterols' molecules by metabolic synthesis in A. oryzae,which will provide clues to produce soybean sterol by microorganisms.