一株高效转化Phytosterol为雄甾烯酮菌株的筛选与鉴定

从保藏的200多株菌中筛选出1株高效转化植物甾醇为4-烯-雄甾-3，17-二酮和1，4-二烯-雄甾-3，17-二酮的菌株，并对该菌进行了形态、生理生化的研究。结果发现菌株ST06可以利用多种碳源，可以水解淀粉，但不利用纤微素。用16SrDNA的方法对其进行鉴定，发现与Bacillus属Bacillus amyloiquefaciens的相似性最高，达到99．9％，将该菌株命名为Bacillus amyloiquefaciens ST06。该菌在培养温度30℃，pH7．0，转速220r／min，转化时间7d，底物添加量为0．3％时，ADD与AD的总得率高达40％以上，此时底物转化率高达93．7％。

Screening and Characterization of an Efficient Strain for Biotransforming Phytosterol into Androstenone

A strain screened from over 200 conserved collections was isolated with its efficiently transformation ability of phytosterol into androst-4-end-3, 17-dione （4-AD） and androst-1 , 4-end-3, 17-dione （ADD） and studied on its morphology and physiochemistry. It was found that strain ST06 could utilize many kinds of carbon source, could hydrolyze starch, and however could not utilize cellulose. It was found through characterization with 16S rRNA sequencing that it had the highest similarity （up to 99.9% ） with Bacillus amyloiquefaciens, therefore, it was named as B. amyloiquefaciens ST06. Culture the strain at 30℃ , pH 7.0 and 220 rpm transforming for 7 days, when the addition of substrate at 0.3%, total yielding rate of AD and ADD was as much as 40%, and transformation rate of substrate was as high as 93.7%.